2021-08-28 17:25:59 +02:00
|
|
|
.TH PCRE2API 3 "28 August 2021" "PCRE2 10.38"
|
2014-09-19 09:43:39 +02:00
|
|
|
.SH NAME
|
|
|
|
PCRE2 - Perl-compatible regular expressions (revised API)
|
|
|
|
.sp
|
|
|
|
.B #include <pcre2.h>
|
|
|
|
.sp
|
2017-04-20 18:34:35 +02:00
|
|
|
PCRE2 is a new API for PCRE, starting at release 10.0. This document contains a
|
|
|
|
description of all its native functions. See the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2\fP
|
|
|
|
.\"
|
|
|
|
document for an overview of all the PCRE2 documentation.
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH "PCRE2 NATIVE API BASIC FUNCTIONS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B pcre2_code *pcre2_compile(PCRE2_SPTR \fIpattern\fP, PCRE2_SIZE \fIlength\fP,
|
|
|
|
.B " uint32_t \fIoptions\fP, int *\fIerrorcode\fP, PCRE2_SIZE *\fIerroroffset,\fP"
|
|
|
|
.B " pcre2_compile_context *\fIccontext\fP);"
|
|
|
|
.sp
|
2015-07-29 10:03:34 +02:00
|
|
|
.B void pcre2_code_free(pcre2_code *\fIcode\fP);
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2015-07-29 10:03:34 +02:00
|
|
|
.B pcre2_match_data *pcre2_match_data_create(uint32_t \fIovecsize\fP,
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " pcre2_general_context *\fIgcontext\fP);"
|
|
|
|
.sp
|
2015-07-29 10:03:34 +02:00
|
|
|
.B pcre2_match_data *pcre2_match_data_create_from_pattern(
|
|
|
|
.B " const pcre2_code *\fIcode\fP, pcre2_general_context *\fIgcontext\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
.B int pcre2_match(const pcre2_code *\fIcode\fP, PCRE2_SPTR \fIsubject\fP,
|
|
|
|
.B " PCRE2_SIZE \fIlength\fP, PCRE2_SIZE \fIstartoffset\fP,"
|
|
|
|
.B " uint32_t \fIoptions\fP, pcre2_match_data *\fImatch_data\fP,"
|
|
|
|
.B " pcre2_match_context *\fImcontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_dfa_match(const pcre2_code *\fIcode\fP, PCRE2_SPTR \fIsubject\fP,
|
|
|
|
.B " PCRE2_SIZE \fIlength\fP, PCRE2_SIZE \fIstartoffset\fP,"
|
|
|
|
.B " uint32_t \fIoptions\fP, pcre2_match_data *\fImatch_data\fP,"
|
|
|
|
.B " pcre2_match_context *\fImcontext\fP,"
|
|
|
|
.B " int *\fIworkspace\fP, PCRE2_SIZE \fIwscount\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_match_data_free(pcre2_match_data *\fImatch_data\fP);
|
|
|
|
.fi
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH "PCRE2 NATIVE API AUXILIARY MATCH FUNCTIONS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B PCRE2_SPTR pcre2_get_mark(pcre2_match_data *\fImatch_data\fP);
|
|
|
|
.sp
|
|
|
|
.B uint32_t pcre2_get_ovector_count(pcre2_match_data *\fImatch_data\fP);
|
|
|
|
.sp
|
|
|
|
.B PCRE2_SIZE *pcre2_get_ovector_pointer(pcre2_match_data *\fImatch_data\fP);
|
|
|
|
.sp
|
|
|
|
.B PCRE2_SIZE pcre2_get_startchar(pcre2_match_data *\fImatch_data\fP);
|
|
|
|
.fi
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH "PCRE2 NATIVE API GENERAL CONTEXT FUNCTIONS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B pcre2_general_context *pcre2_general_context_create(
|
|
|
|
.B " void *(*\fIprivate_malloc\fP)(PCRE2_SIZE, void *),"
|
|
|
|
.B " void (*\fIprivate_free\fP)(void *, void *), void *\fImemory_data\fP);"
|
|
|
|
.sp
|
|
|
|
.B pcre2_general_context *pcre2_general_context_copy(
|
|
|
|
.B " pcre2_general_context *\fIgcontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_general_context_free(pcre2_general_context *\fIgcontext\fP);
|
|
|
|
.fi
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH "PCRE2 NATIVE API COMPILE CONTEXT FUNCTIONS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B pcre2_compile_context *pcre2_compile_context_create(
|
|
|
|
.B " pcre2_general_context *\fIgcontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B pcre2_compile_context *pcre2_compile_context_copy(
|
|
|
|
.B " pcre2_compile_context *\fIccontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_compile_context_free(pcre2_compile_context *\fIccontext\fP);
|
|
|
|
.sp
|
2014-10-01 19:02:33 +02:00
|
|
|
.B int pcre2_set_bsr(pcre2_compile_context *\fIccontext\fP,
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " uint32_t \fIvalue\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_set_character_tables(pcre2_compile_context *\fIccontext\fP,
|
2019-07-28 17:58:24 +02:00
|
|
|
.B " const uint8_t *\fItables\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2017-05-17 19:55:11 +02:00
|
|
|
.B int pcre2_set_compile_extra_options(pcre2_compile_context *\fIccontext\fP,
|
|
|
|
.B " uint32_t \fIextra_options\fP);"
|
|
|
|
.sp
|
2015-11-05 18:33:39 +01:00
|
|
|
.B int pcre2_set_max_pattern_length(pcre2_compile_context *\fIccontext\fP,
|
|
|
|
.B " PCRE2_SIZE \fIvalue\fP);"
|
|
|
|
.sp
|
2014-10-01 19:02:33 +02:00
|
|
|
.B int pcre2_set_newline(pcre2_compile_context *\fIccontext\fP,
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " uint32_t \fIvalue\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_set_parens_nest_limit(pcre2_compile_context *\fIccontext\fP,
|
|
|
|
.B " uint32_t \fIvalue\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_set_compile_recursion_guard(pcre2_compile_context *\fIccontext\fP,
|
2014-11-26 17:51:53 +01:00
|
|
|
.B " int (*\fIguard_function\fP)(uint32_t, void *), void *\fIuser_data\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.fi
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH "PCRE2 NATIVE API MATCH CONTEXT FUNCTIONS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B pcre2_match_context *pcre2_match_context_create(
|
|
|
|
.B " pcre2_general_context *\fIgcontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B pcre2_match_context *pcre2_match_context_copy(
|
|
|
|
.B " pcre2_match_context *\fImcontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_match_context_free(pcre2_match_context *\fImcontext\fP);
|
|
|
|
.sp
|
|
|
|
.B int pcre2_set_callout(pcre2_match_context *\fImcontext\fP,
|
2014-11-25 18:35:01 +01:00
|
|
|
.B " int (*\fIcallout_function\fP)(pcre2_callout_block *, void *),"
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " void *\fIcallout_data\fP);"
|
|
|
|
.sp
|
2018-09-18 18:31:30 +02:00
|
|
|
.B int pcre2_set_substitute_callout(pcre2_match_context *\fImcontext\fP,
|
2018-11-12 17:02:01 +01:00
|
|
|
.B " int (*\fIcallout_function\fP)(pcre2_substitute_callout_block *, void *),"
|
2018-09-18 18:31:30 +02:00
|
|
|
.B " void *\fIcallout_data\fP);"
|
|
|
|
.sp
|
2015-09-22 18:51:11 +02:00
|
|
|
.B int pcre2_set_offset_limit(pcre2_match_context *\fImcontext\fP,
|
|
|
|
.B " PCRE2_SIZE \fIvalue\fP);"
|
|
|
|
.sp
|
2017-04-11 13:47:25 +02:00
|
|
|
.B int pcre2_set_heap_limit(pcre2_match_context *\fImcontext\fP,
|
|
|
|
.B " uint32_t \fIvalue\fP);"
|
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
.B int pcre2_set_match_limit(pcre2_match_context *\fImcontext\fP,
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " uint32_t \fIvalue\fP);"
|
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
.B int pcre2_set_depth_limit(pcre2_match_context *\fImcontext\fP,
|
|
|
|
.B " uint32_t \fIvalue\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.fi
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH "PCRE2 NATIVE API STRING EXTRACTION FUNCTIONS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_substring_copy_byname(pcre2_match_data *\fImatch_data\fP,
|
|
|
|
.B " PCRE2_SPTR \fIname\fP, PCRE2_UCHAR *\fIbuffer\fP, PCRE2_SIZE *\fIbufflen\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_substring_copy_bynumber(pcre2_match_data *\fImatch_data\fP,
|
2014-12-01 17:14:53 +01:00
|
|
|
.B " uint32_t \fInumber\fP, PCRE2_UCHAR *\fIbuffer\fP,"
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " PCRE2_SIZE *\fIbufflen\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_substring_free(PCRE2_UCHAR *\fIbuffer\fP);
|
|
|
|
.sp
|
|
|
|
.B int pcre2_substring_get_byname(pcre2_match_data *\fImatch_data\fP,
|
|
|
|
.B " PCRE2_SPTR \fIname\fP, PCRE2_UCHAR **\fIbufferptr\fP, PCRE2_SIZE *\fIbufflen\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_substring_get_bynumber(pcre2_match_data *\fImatch_data\fP,
|
2014-12-01 17:14:53 +01:00
|
|
|
.B " uint32_t \fInumber\fP, PCRE2_UCHAR **\fIbufferptr\fP,"
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " PCRE2_SIZE *\fIbufflen\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_substring_length_byname(pcre2_match_data *\fImatch_data\fP,
|
|
|
|
.B " PCRE2_SPTR \fIname\fP, PCRE2_SIZE *\fIlength\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_substring_length_bynumber(pcre2_match_data *\fImatch_data\fP,
|
2014-12-01 17:14:53 +01:00
|
|
|
.B " uint32_t \fInumber\fP, PCRE2_SIZE *\fIlength\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
.B int pcre2_substring_nametable_scan(const pcre2_code *\fIcode\fP,
|
|
|
|
.B " PCRE2_SPTR \fIname\fP, PCRE2_SPTR *\fIfirst\fP, PCRE2_SPTR *\fIlast\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_substring_number_from_name(const pcre2_code *\fIcode\fP,
|
|
|
|
.B " PCRE2_SPTR \fIname\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_substring_list_free(PCRE2_SPTR *\fIlist\fP);
|
|
|
|
.sp
|
|
|
|
.B int pcre2_substring_list_get(pcre2_match_data *\fImatch_data\fP,
|
|
|
|
.B " PCRE2_UCHAR ***\fIlistptr\fP, PCRE2_SIZE **\fIlengthsptr\fP);
|
|
|
|
.fi
|
|
|
|
.
|
|
|
|
.
|
2014-11-11 17:51:07 +01:00
|
|
|
.SH "PCRE2 NATIVE API STRING SUBSTITUTION FUNCTION"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_substitute(const pcre2_code *\fIcode\fP, PCRE2_SPTR \fIsubject\fP,
|
|
|
|
.B " PCRE2_SIZE \fIlength\fP, PCRE2_SIZE \fIstartoffset\fP,"
|
|
|
|
.B " uint32_t \fIoptions\fP, pcre2_match_data *\fImatch_data\fP,"
|
2020-04-24 18:05:36 +02:00
|
|
|
.B " pcre2_match_context *\fImcontext\fP, PCRE2_SPTR \fIreplacementz\fP,"
|
2014-11-11 17:51:07 +01:00
|
|
|
.B " PCRE2_SIZE \fIrlength\fP, PCRE2_UCHAR *\fIoutputbuffer\fP,"
|
|
|
|
.B " PCRE2_SIZE *\fIoutlengthptr\fP);"
|
|
|
|
.fi
|
|
|
|
.
|
|
|
|
.
|
2014-09-19 09:43:39 +02:00
|
|
|
.SH "PCRE2 NATIVE API JIT FUNCTIONS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_jit_compile(pcre2_code *\fIcode\fP, uint32_t \fIoptions\fP);
|
|
|
|
.sp
|
|
|
|
.B int pcre2_jit_match(const pcre2_code *\fIcode\fP, PCRE2_SPTR \fIsubject\fP,
|
|
|
|
.B " PCRE2_SIZE \fIlength\fP, PCRE2_SIZE \fIstartoffset\fP,"
|
|
|
|
.B " uint32_t \fIoptions\fP, pcre2_match_data *\fImatch_data\fP,"
|
2014-11-08 17:09:24 +01:00
|
|
|
.B " pcre2_match_context *\fImcontext\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
.B void pcre2_jit_free_unused_memory(pcre2_general_context *\fIgcontext\fP);
|
|
|
|
.sp
|
2014-11-28 13:46:16 +01:00
|
|
|
.B pcre2_jit_stack *pcre2_jit_stack_create(PCRE2_SIZE \fIstartsize\fP,
|
|
|
|
.B " PCRE2_SIZE \fImaxsize\fP, pcre2_general_context *\fIgcontext\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2014-11-08 17:09:24 +01:00
|
|
|
.B void pcre2_jit_stack_assign(pcre2_match_context *\fImcontext\fP,
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " pcre2_jit_callback \fIcallback_function\fP, void *\fIcallback_data\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_jit_stack_free(pcre2_jit_stack *\fIjit_stack\fP);
|
|
|
|
.fi
|
|
|
|
.
|
|
|
|
.
|
2015-01-23 17:51:47 +01:00
|
|
|
.SH "PCRE2 NATIVE API SERIALIZATION FUNCTIONS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int32_t pcre2_serialize_decode(pcre2_code **\fIcodes\fP,
|
2015-09-03 17:27:43 +02:00
|
|
|
.B " int32_t \fInumber_of_codes\fP, const uint8_t *\fIbytes\fP,"
|
2015-01-23 17:51:47 +01:00
|
|
|
.B " pcre2_general_context *\fIgcontext\fP);"
|
|
|
|
.sp
|
2015-09-03 17:27:43 +02:00
|
|
|
.B int32_t pcre2_serialize_encode(const pcre2_code **\fIcodes\fP,
|
|
|
|
.B " int32_t \fInumber_of_codes\fP, uint8_t **\fIserialized_bytes\fP,"
|
2015-01-23 17:51:47 +01:00
|
|
|
.B " PCRE2_SIZE *\fIserialized_size\fP, pcre2_general_context *\fIgcontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_serialize_free(uint8_t *\fIbytes\fP);
|
|
|
|
.sp
|
|
|
|
.B int32_t pcre2_serialize_get_number_of_codes(const uint8_t *\fIbytes\fP);
|
|
|
|
.fi
|
|
|
|
.
|
|
|
|
.
|
2014-09-19 09:43:39 +02:00
|
|
|
.SH "PCRE2 NATIVE API AUXILIARY FUNCTIONS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
2016-02-26 19:26:17 +01:00
|
|
|
.B pcre2_code *pcre2_code_copy(const pcre2_code *\fIcode\fP);
|
|
|
|
.sp
|
2016-11-22 16:37:02 +01:00
|
|
|
.B pcre2_code *pcre2_code_copy_with_tables(const pcre2_code *\fIcode\fP);
|
|
|
|
.sp
|
2014-09-19 09:43:39 +02:00
|
|
|
.B int pcre2_get_error_message(int \fIerrorcode\fP, PCRE2_UCHAR *\fIbuffer\fP,
|
|
|
|
.B " PCRE2_SIZE \fIbufflen\fP);"
|
|
|
|
.sp
|
2019-08-01 18:49:09 +02:00
|
|
|
.B const uint8_t *pcre2_maketables(pcre2_general_context *\fIgcontext\fP);
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2019-10-17 18:39:38 +02:00
|
|
|
.B void pcre2_maketables_free(pcre2_general_context *\fIgcontext\fP,
|
2019-09-03 16:16:07 +02:00
|
|
|
.B " const uint8_t *\fItables\fP);"
|
|
|
|
.sp
|
2019-03-04 19:07:04 +01:00
|
|
|
.B int pcre2_pattern_info(const pcre2_code *\fIcode\fP, uint32_t \fIwhat\fP,
|
2019-02-14 17:07:14 +01:00
|
|
|
.B " void *\fIwhere\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2015-03-23 16:52:08 +01:00
|
|
|
.B int pcre2_callout_enumerate(const pcre2_code *\fIcode\fP,
|
|
|
|
.B " int (*\fIcallback\fP)(pcre2_callout_enumerate_block *, void *),"
|
|
|
|
.B " void *\fIuser_data\fP);"
|
|
|
|
.sp
|
2014-10-15 18:44:12 +02:00
|
|
|
.B int pcre2_config(uint32_t \fIwhat\fP, void *\fIwhere\fP);
|
2014-09-23 13:35:51 +02:00
|
|
|
.fi
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
2017-03-28 18:34:29 +02:00
|
|
|
.SH "PCRE2 NATIVE API OBSOLETE FUNCTIONS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_set_recursion_limit(pcre2_match_context *\fImcontext\fP,
|
|
|
|
.B " uint32_t \fIvalue\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_set_recursion_memory_management(
|
|
|
|
.B " pcre2_match_context *\fImcontext\fP,"
|
|
|
|
.B " void *(*\fIprivate_malloc\fP)(PCRE2_SIZE, void *),"
|
|
|
|
.B " void (*\fIprivate_free\fP)(void *, void *), void *\fImemory_data\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
2017-05-30 12:42:57 +02:00
|
|
|
These functions became obsolete at release 10.30 and are retained only for
|
2017-03-28 18:34:29 +02:00
|
|
|
backward compatibility. They should not be used in new code. The first is
|
|
|
|
replaced by \fBpcre2_set_depth_limit()\fP; the second is no longer needed and
|
2017-04-20 18:34:35 +02:00
|
|
|
has no effect (it always returns zero).
|
2017-03-28 18:34:29 +02:00
|
|
|
.
|
|
|
|
.
|
2017-07-12 18:34:49 +02:00
|
|
|
.SH "PCRE2 EXPERIMENTAL PATTERN CONVERSION FUNCTIONS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B pcre2_convert_context *pcre2_convert_context_create(
|
|
|
|
.B " pcre2_general_context *\fIgcontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B pcre2_convert_context *pcre2_convert_context_copy(
|
|
|
|
.B " pcre2_convert_context *\fIcvcontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_convert_context_free(pcre2_convert_context *\fIcvcontext\fP);
|
|
|
|
.sp
|
|
|
|
.B int pcre2_set_glob_escape(pcre2_convert_context *\fIcvcontext\fP,
|
|
|
|
.B " uint32_t \fIescape_char\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_set_glob_separator(pcre2_convert_context *\fIcvcontext\fP,
|
|
|
|
.B " uint32_t \fIseparator_char\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_pattern_convert(PCRE2_SPTR \fIpattern\fP, PCRE2_SIZE \fIlength\fP,
|
|
|
|
.B " uint32_t \fIoptions\fP, PCRE2_UCHAR **\fIbuffer\fP,"
|
|
|
|
.B " PCRE2_SIZE *\fIblength\fP, pcre2_convert_context *\fIcvcontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_converted_pattern_free(PCRE2_UCHAR *\fIconverted_pattern\fP);
|
|
|
|
.fi
|
|
|
|
.sp
|
|
|
|
These functions provide a way of converting non-PCRE2 patterns into
|
|
|
|
patterns that can be processed by \fBpcre2_compile()\fP. This facility is
|
|
|
|
experimental and may be changed in future releases. At present, "globs" and
|
|
|
|
POSIX basic and extended patterns can be converted. Details are given in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2convert\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
|
|
|
.
|
|
|
|
.
|
2014-09-19 09:43:39 +02:00
|
|
|
.SH "PCRE2 8-BIT, 16-BIT, AND 32-BIT LIBRARIES"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
There are three PCRE2 libraries, supporting 8-bit, 16-bit, and 32-bit code
|
|
|
|
units, respectively. However, there is just one header file, \fBpcre2.h\fP.
|
|
|
|
This contains the function prototypes and other definitions for all three
|
|
|
|
libraries. One, two, or all three can be installed simultaneously. On Unix-like
|
|
|
|
systems the libraries are called \fBlibpcre2-8\fP, \fBlibpcre2-16\fP, and
|
|
|
|
\fBlibpcre2-32\fP, and they can also co-exist with the original PCRE libraries.
|
|
|
|
.P
|
|
|
|
Character strings are passed to and from a PCRE2 library as a sequence of
|
|
|
|
unsigned integers in code units of the appropriate width. Every PCRE2 function
|
|
|
|
comes in three different forms, one for each library, for example:
|
|
|
|
.sp
|
|
|
|
\fBpcre2_compile_8()\fP
|
|
|
|
\fBpcre2_compile_16()\fP
|
|
|
|
\fBpcre2_compile_32()\fP
|
|
|
|
.sp
|
|
|
|
There are also three different sets of data types:
|
|
|
|
.sp
|
|
|
|
\fBPCRE2_UCHAR8, PCRE2_UCHAR16, PCRE2_UCHAR32\fP
|
|
|
|
\fBPCRE2_SPTR8, PCRE2_SPTR16, PCRE2_SPTR32\fP
|
|
|
|
.sp
|
|
|
|
The UCHAR types define unsigned code units of the appropriate widths. For
|
|
|
|
example, PCRE2_UCHAR16 is usually defined as `uint16_t'. The SPTR types are
|
|
|
|
constant pointers to the equivalent UCHAR types, that is, they are pointers to
|
|
|
|
vectors of unsigned code units.
|
|
|
|
.P
|
|
|
|
Many applications use only one code unit width. For their convenience, macros
|
|
|
|
are defined whose names are the generic forms such as \fBpcre2_compile()\fP and
|
|
|
|
PCRE2_SPTR. These macros use the value of the macro PCRE2_CODE_UNIT_WIDTH to
|
|
|
|
generate the appropriate width-specific function and macro names.
|
|
|
|
PCRE2_CODE_UNIT_WIDTH is not defined by default. An application must define it
|
|
|
|
to be 8, 16, or 32 before including \fBpcre2.h\fP in order to make use of the
|
|
|
|
generic names.
|
|
|
|
.P
|
|
|
|
Applications that use more than one code unit width can be linked with more
|
|
|
|
than one PCRE2 library, but must define PCRE2_CODE_UNIT_WIDTH to be 0 before
|
|
|
|
including \fBpcre2.h\fP, and then use the real function names. Any code that is
|
|
|
|
to be included in an environment where the value of PCRE2_CODE_UNIT_WIDTH is
|
|
|
|
unknown should also use the real function names. (Unfortunately, it is not
|
|
|
|
possible in C code to save and restore the value of a macro.)
|
|
|
|
.P
|
2014-10-20 19:28:49 +02:00
|
|
|
If PCRE2_CODE_UNIT_WIDTH is not defined before including \fBpcre2.h\fP, a
|
2014-09-19 09:43:39 +02:00
|
|
|
compiler error occurs.
|
|
|
|
.P
|
|
|
|
When using multiple libraries in an application, you must take care when
|
|
|
|
processing any particular pattern to use only functions from a single library.
|
|
|
|
For example, if you want to run a match using a pattern that was compiled with
|
|
|
|
\fBpcre2_compile_16()\fP, you must do so with \fBpcre2_match_16()\fP, not
|
2017-04-08 17:21:39 +02:00
|
|
|
\fBpcre2_match_8()\fP or \fBpcre2_match_32()\fP.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
In the function summaries above, and in the rest of this document and other
|
|
|
|
PCRE2 documents, functions and data types are described using their generic
|
2017-04-20 18:34:35 +02:00
|
|
|
names, without the _8, _16, or _32 suffix.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH "PCRE2 API OVERVIEW"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
PCRE2 has its own native API, which is described in this document. There are
|
|
|
|
also some wrapper functions for the 8-bit library that correspond to the
|
|
|
|
POSIX regular expression API, but they do not give access to all the
|
2017-04-20 18:34:35 +02:00
|
|
|
functionality of PCRE2. They are described in the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2posix\fP
|
|
|
|
.\"
|
|
|
|
documentation. Both these APIs define a set of C function calls.
|
|
|
|
.P
|
|
|
|
The native API C data types, function prototypes, option values, and error
|
2017-04-20 18:34:35 +02:00
|
|
|
codes are defined in the header file \fBpcre2.h\fP, which also contains
|
|
|
|
definitions of PCRE2_MAJOR and PCRE2_MINOR, the major and minor release numbers
|
|
|
|
for the library. Applications can use these to include support for different
|
|
|
|
releases of PCRE2.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
In a Windows environment, if you want to statically link an application program
|
|
|
|
against a non-dll PCRE2 library, you must define PCRE2_STATIC before including
|
|
|
|
\fBpcre2.h\fP.
|
|
|
|
.P
|
2017-03-28 18:34:29 +02:00
|
|
|
The functions \fBpcre2_compile()\fP and \fBpcre2_match()\fP are used for
|
2014-09-19 09:43:39 +02:00
|
|
|
compiling and matching regular expressions in a Perl-compatible manner. A
|
|
|
|
sample program that demonstrates the simplest way of using them is provided in
|
|
|
|
the file called \fIpcre2demo.c\fP in the PCRE2 source distribution. A listing
|
|
|
|
of this program is given in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2demo\fP
|
|
|
|
.\"
|
|
|
|
documentation, and the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2sample\fP
|
|
|
|
.\"
|
|
|
|
documentation describes how to compile and run it.
|
|
|
|
.P
|
2017-05-30 12:42:57 +02:00
|
|
|
The compiling and matching functions recognize various options that are passed
|
|
|
|
as bits in an options argument. There are also some more complicated parameters
|
|
|
|
such as custom memory management functions and resource limits that are passed
|
|
|
|
in "contexts" (which are just memory blocks, described below). Simple
|
2017-03-28 18:34:29 +02:00
|
|
|
applications do not need to make use of contexts.
|
|
|
|
.P
|
|
|
|
Just-in-time (JIT) compiler support is an optional feature of PCRE2 that can be
|
|
|
|
built in appropriate hardware environments. It greatly speeds up the matching
|
2014-09-19 09:43:39 +02:00
|
|
|
performance of many patterns. Programs can request that it be used if
|
2017-03-28 18:34:29 +02:00
|
|
|
available by calling \fBpcre2_jit_compile()\fP after a pattern has been
|
2014-09-19 09:43:39 +02:00
|
|
|
successfully compiled by \fBpcre2_compile()\fP. This does nothing if JIT
|
|
|
|
support is not available.
|
|
|
|
.P
|
|
|
|
More complicated programs might need to make use of the specialist functions
|
2014-11-03 18:13:00 +01:00
|
|
|
\fBpcre2_jit_stack_create()\fP, \fBpcre2_jit_stack_free()\fP, and
|
2014-09-19 09:43:39 +02:00
|
|
|
\fBpcre2_jit_stack_assign()\fP in order to control the JIT code's memory usage.
|
|
|
|
.P
|
2016-06-05 18:05:34 +02:00
|
|
|
JIT matching is automatically used by \fBpcre2_match()\fP if it is available,
|
|
|
|
unless the PCRE2_NO_JIT option is set. There is also a direct interface for JIT
|
2017-05-30 12:42:57 +02:00
|
|
|
matching, which gives improved performance at the expense of less sanity
|
2017-03-28 18:34:29 +02:00
|
|
|
checking. The JIT-specific functions are discussed in the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2jit\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
|
|
|
.P
|
2014-10-21 18:33:30 +02:00
|
|
|
A second matching function, \fBpcre2_dfa_match()\fP, which is not
|
2014-09-19 09:43:39 +02:00
|
|
|
Perl-compatible, is also provided. This uses a different algorithm for the
|
|
|
|
matching. The alternative algorithm finds all possible matches (at a given
|
|
|
|
point in the subject), and scans the subject just once (unless there are
|
2017-03-28 18:34:29 +02:00
|
|
|
lookaround assertions). However, this algorithm does not return captured
|
2014-09-19 09:43:39 +02:00
|
|
|
substrings. A description of the two matching algorithms and their advantages
|
|
|
|
and disadvantages is given in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2matching\fP
|
|
|
|
.\"
|
|
|
|
documentation. There is no JIT support for \fBpcre2_dfa_match()\fP.
|
|
|
|
.P
|
|
|
|
In addition to the main compiling and matching functions, there are convenience
|
2014-11-11 17:51:07 +01:00
|
|
|
functions for extracting captured substrings from a subject string that has
|
|
|
|
been matched by \fBpcre2_match()\fP. They are:
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
\fBpcre2_substring_copy_byname()\fP
|
|
|
|
\fBpcre2_substring_copy_bynumber()\fP
|
|
|
|
\fBpcre2_substring_get_byname()\fP
|
|
|
|
\fBpcre2_substring_get_bynumber()\fP
|
|
|
|
\fBpcre2_substring_list_get()\fP
|
|
|
|
\fBpcre2_substring_length_byname()\fP
|
|
|
|
\fBpcre2_substring_length_bynumber()\fP
|
|
|
|
\fBpcre2_substring_nametable_scan()\fP
|
|
|
|
\fBpcre2_substring_number_from_name()\fP
|
|
|
|
.sp
|
|
|
|
\fBpcre2_substring_free()\fP and \fBpcre2_substring_list_free()\fP are also
|
2018-08-13 13:57:09 +02:00
|
|
|
provided, to free memory used for extracted strings. If either of these
|
|
|
|
functions is called with a NULL argument, the function returns immediately
|
2018-06-28 18:26:03 +02:00
|
|
|
without doing anything.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2014-11-11 17:51:07 +01:00
|
|
|
The function \fBpcre2_substitute()\fP can be called to match a pattern and
|
|
|
|
return a copy of the subject string with substitutions for parts that were
|
|
|
|
matched.
|
|
|
|
.P
|
2016-02-06 13:45:56 +01:00
|
|
|
Functions whose names begin with \fBpcre2_serialize_\fP are used for saving
|
|
|
|
compiled patterns on disc or elsewhere, and reloading them later.
|
|
|
|
.P
|
2014-11-11 17:51:07 +01:00
|
|
|
Finally, there are functions for finding out information about a compiled
|
|
|
|
pattern (\fBpcre2_pattern_info()\fP) and about the configuration with which
|
|
|
|
PCRE2 was built (\fBpcre2_config()\fP).
|
2016-02-06 13:45:56 +01:00
|
|
|
.P
|
|
|
|
Functions with names ending with \fB_free()\fP are used for freeing memory
|
|
|
|
blocks of various sorts. In all cases, if one of these functions is called with
|
|
|
|
a NULL argument, it does nothing.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
2014-11-25 18:50:28 +01:00
|
|
|
.SH "STRING LENGTHS AND OFFSETS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
The PCRE2 API uses string lengths and offsets into strings of code units in
|
|
|
|
several places. These values are always of type PCRE2_SIZE, which is an
|
2014-11-26 17:51:53 +01:00
|
|
|
unsigned integer type, currently always defined as \fIsize_t\fP. The largest
|
|
|
|
value that can be stored in such a type (that is ~(PCRE2_SIZE)0) is reserved
|
|
|
|
as a special indicator for zero-terminated strings and unset offsets.
|
|
|
|
Therefore, the longest string that can be handled is one less than this
|
|
|
|
maximum.
|
2014-11-25 18:50:28 +01:00
|
|
|
.
|
|
|
|
.
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HTML <a name="newlines"></a>
|
|
|
|
.SH NEWLINES
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
PCRE2 supports five different conventions for indicating line breaks in
|
|
|
|
strings: a single CR (carriage return) character, a single LF (linefeed)
|
|
|
|
character, the two-character sequence CRLF, any of the three preceding, or any
|
|
|
|
Unicode newline sequence. The Unicode newline sequences are the three just
|
|
|
|
mentioned, plus the single characters VT (vertical tab, U+000B), FF (form feed,
|
|
|
|
U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and PS
|
|
|
|
(paragraph separator, U+2029).
|
|
|
|
.P
|
|
|
|
Each of the first three conventions is used by at least one operating system as
|
|
|
|
its standard newline sequence. When PCRE2 is built, a default can be specified.
|
2018-06-17 16:13:28 +02:00
|
|
|
If it is not, the default is set to LF, which is the Unix standard. However,
|
|
|
|
the newline convention can be changed by an application when calling
|
|
|
|
\fBpcre2_compile()\fP, or it can be specified by special text at the start of
|
|
|
|
the pattern itself; this overrides any other settings. See the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2pattern\fP
|
|
|
|
.\"
|
|
|
|
page for details of the special character sequences.
|
|
|
|
.P
|
|
|
|
In the PCRE2 documentation the word "newline" is used to mean "the character or
|
|
|
|
pair of characters that indicate a line break". The choice of newline
|
|
|
|
convention affects the handling of the dot, circumflex, and dollar
|
|
|
|
metacharacters, the handling of #-comments in /x mode, and, when CRLF is a
|
|
|
|
recognized line ending sequence, the match position advancement for a
|
|
|
|
non-anchored pattern. There is more detail about this in the
|
|
|
|
.\" HTML <a href="#matchoptions">
|
|
|
|
.\" </a>
|
|
|
|
section on \fBpcre2_match()\fP options
|
|
|
|
.\"
|
|
|
|
below.
|
|
|
|
.P
|
|
|
|
The choice of newline convention does not affect the interpretation of
|
2014-11-18 19:32:12 +01:00
|
|
|
the \en or \er escape sequences, nor does it affect what \eR matches; this has
|
|
|
|
its own separate convention.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH MULTITHREADING
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
In a multithreaded application it is important to keep thread-specific data
|
|
|
|
separate from data that can be shared between threads. The PCRE2 library code
|
|
|
|
itself is thread-safe: it contains no static or global variables. The API is
|
|
|
|
designed to be fairly simple for non-threaded applications while at the same
|
|
|
|
time ensuring that multithreaded applications can use it.
|
|
|
|
.P
|
|
|
|
There are several different blocks of data that are used to pass information
|
2014-11-18 19:32:12 +01:00
|
|
|
between the application and the PCRE2 libraries.
|
2016-02-05 20:39:45 +01:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.SS "The compiled pattern"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
A pointer to the compiled form of a pattern is returned to the user when
|
2014-09-19 09:43:39 +02:00
|
|
|
\fBpcre2_compile()\fP is successful. The data in the compiled pattern is fixed,
|
|
|
|
and does not change when the pattern is matched. Therefore, it is thread-safe,
|
|
|
|
that is, the same compiled pattern can be used by more than one thread
|
2016-02-05 20:39:45 +01:00
|
|
|
simultaneously. For example, an application can compile all its patterns at the
|
|
|
|
start, before forking off multiple threads that use them. However, if the
|
2017-03-28 18:34:29 +02:00
|
|
|
just-in-time (JIT) optimization feature is being used, it needs separate memory
|
|
|
|
stack areas for each thread. See the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2jit\fP
|
|
|
|
.\"
|
|
|
|
documentation for more details.
|
|
|
|
.P
|
2016-02-05 20:39:45 +01:00
|
|
|
In a more complicated situation, where patterns are compiled only when they are
|
|
|
|
first needed, but are still shared between threads, pointers to compiled
|
2020-11-04 18:01:13 +01:00
|
|
|
patterns must be protected from simultaneous writing by multiple threads. This
|
|
|
|
is somewhat tricky to do correctly. If you know that writing to a pointer is
|
|
|
|
atomic in your environment, you can use logic like this:
|
2016-02-05 20:39:45 +01:00
|
|
|
.sp
|
2016-02-25 18:40:16 +01:00
|
|
|
Get a read-only (shared) lock (mutex) for pointer
|
2016-02-05 20:39:45 +01:00
|
|
|
if (pointer == NULL)
|
|
|
|
{
|
2016-02-25 18:40:16 +01:00
|
|
|
Get a write (unique) lock for pointer
|
2020-11-04 18:01:13 +01:00
|
|
|
if (pointer == NULL) pointer = pcre2_compile(...
|
2016-02-05 20:39:45 +01:00
|
|
|
}
|
2016-06-05 18:05:34 +02:00
|
|
|
Release the lock
|
2016-02-05 20:39:45 +01:00
|
|
|
Use pointer in pcre2_match()
|
|
|
|
.sp
|
|
|
|
Of course, testing for compilation errors should also be included in the code.
|
|
|
|
.P
|
2020-11-04 18:01:13 +01:00
|
|
|
The reason for checking the pointer a second time is as follows: Several
|
|
|
|
threads may have acquired the shared lock and tested the pointer for being
|
|
|
|
NULL, but only one of them will be given the write lock, with the rest kept
|
|
|
|
waiting. The winning thread will compile the pattern and store the result.
|
|
|
|
After this thread releases the write lock, another thread will get it, and if
|
|
|
|
it does not retest pointer for being NULL, will recompile the pattern and
|
|
|
|
overwrite the pointer, creating a memory leak and possibly causing other
|
|
|
|
issues.
|
|
|
|
.P
|
|
|
|
In an environment where writing to a pointer may not be atomic, the above logic
|
|
|
|
is not sufficient. The thread that is doing the compiling may be descheduled
|
|
|
|
after writing only part of the pointer, which could cause other threads to use
|
|
|
|
an invalid value. Instead of checking the pointer itself, a separate "pointer
|
|
|
|
is valid" flag (that can be updated atomically) must be used:
|
|
|
|
.sp
|
|
|
|
Get a read-only (shared) lock (mutex) for pointer
|
|
|
|
if (!pointer_is_valid)
|
|
|
|
{
|
|
|
|
Get a write (unique) lock for pointer
|
2020-11-06 18:27:35 +01:00
|
|
|
if (!pointer_is_valid)
|
2020-11-04 18:01:13 +01:00
|
|
|
{
|
|
|
|
pointer = pcre2_compile(...
|
|
|
|
pointer_is_valid = TRUE
|
2020-11-06 18:27:35 +01:00
|
|
|
}
|
2020-11-04 18:01:13 +01:00
|
|
|
}
|
|
|
|
Release the lock
|
|
|
|
Use pointer in pcre2_match()
|
|
|
|
.sp
|
|
|
|
If JIT is being used, but the JIT compilation is not being done immediately
|
|
|
|
(perhaps waiting to see if the pattern is used often enough), similar logic is
|
|
|
|
required. JIT compilation updates a value within the compiled code block, so a
|
|
|
|
thread must gain unique write access to the pointer before calling
|
2017-01-16 18:40:47 +01:00
|
|
|
\fBpcre2_jit_compile()\fP. Alternatively, \fBpcre2_code_copy()\fP or
|
2016-11-22 16:37:02 +01:00
|
|
|
\fBpcre2_code_copy_with_tables()\fP can be used to obtain a private copy of the
|
2017-04-20 18:34:35 +02:00
|
|
|
compiled code before calling the JIT compiler.
|
2016-02-05 20:39:45 +01:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.SS "Context blocks"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
The next main section below introduces the idea of "contexts" in which PCRE2
|
2014-09-19 09:43:39 +02:00
|
|
|
functions are called. A context is nothing more than a collection of parameters
|
|
|
|
that control the way PCRE2 operates. Grouping a number of parameters together
|
|
|
|
in a context is a convenient way of passing them to a PCRE2 function without
|
|
|
|
using lots of arguments. The parameters that are stored in contexts are in some
|
|
|
|
sense "advanced features" of the API. Many straightforward applications will
|
|
|
|
not need to use contexts.
|
|
|
|
.P
|
|
|
|
In a multithreaded application, if the parameters in a context are values that
|
|
|
|
are never changed, the same context can be used by all the threads. However, if
|
|
|
|
any thread needs to change any value in a context, it must make its own
|
|
|
|
thread-specific copy.
|
2016-02-05 20:39:45 +01:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.SS "Match blocks"
|
|
|
|
.rs
|
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
The matching functions need a block of memory for storing the results of a
|
|
|
|
match. This includes details of what was matched, as well as additional
|
|
|
|
information such as the name of a (*MARK) setting. Each thread must provide its
|
|
|
|
own copy of this memory.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH "PCRE2 CONTEXTS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
Some PCRE2 functions have a lot of parameters, many of which are used only by
|
|
|
|
specialist applications, for example, those that use custom memory management
|
|
|
|
or non-standard character tables. To keep function argument lists at a
|
|
|
|
reasonable size, and at the same time to keep the API extensible, "uncommon"
|
|
|
|
parameters are passed to certain functions in a \fBcontext\fP instead of
|
|
|
|
directly. A context is just a block of memory that holds the parameter values.
|
|
|
|
Applications that do not need to adjust any of the context parameters can pass
|
|
|
|
NULL when a context pointer is required.
|
|
|
|
.P
|
|
|
|
There are three different types of context: a general context that is relevant
|
|
|
|
for several PCRE2 operations, a compile-time context, and a match-time context.
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.SS "The general context"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
At present, this context just contains pointers to (and data for) external
|
|
|
|
memory management functions that are called from several places in the PCRE2
|
|
|
|
library. The context is named `general' rather than specifically `memory'
|
|
|
|
because in future other fields may be added. If you do not want to supply your
|
|
|
|
own custom memory management functions, you do not need to bother with a
|
|
|
|
general context. A general context is created by:
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B pcre2_general_context *pcre2_general_context_create(
|
|
|
|
.B " void *(*\fIprivate_malloc\fP)(PCRE2_SIZE, void *),"
|
|
|
|
.B " void (*\fIprivate_free\fP)(void *, void *), void *\fImemory_data\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
|
|
|
The two function pointers specify custom memory management functions, whose
|
|
|
|
prototypes are:
|
|
|
|
.sp
|
|
|
|
\fBvoid *private_malloc(PCRE2_SIZE, void *);\fP
|
|
|
|
\fBvoid private_free(void *, void *);\fP
|
|
|
|
.sp
|
|
|
|
Whenever code in PCRE2 calls these functions, the final argument is the value
|
|
|
|
of \fImemory_data\fP. Either of the first two arguments of the creation
|
|
|
|
function may be NULL, in which case the system memory management functions
|
|
|
|
\fImalloc()\fP and \fIfree()\fP are used. (This is not currently useful, as
|
|
|
|
there are no other fields in a general context, but in future there might be.)
|
|
|
|
The \fIprivate_malloc()\fP function is used (if supplied) to obtain memory for
|
|
|
|
storing the context, and all three values are saved as part of the context.
|
|
|
|
.P
|
|
|
|
Whenever PCRE2 creates a data block of any kind, the block contains a pointer
|
|
|
|
to the \fIfree()\fP function that matches the \fImalloc()\fP function that was
|
|
|
|
used. When the time comes to free the block, this function is called.
|
|
|
|
.P
|
|
|
|
A general context can be copied by calling:
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B pcre2_general_context *pcre2_general_context_copy(
|
|
|
|
.B " pcre2_general_context *\fIgcontext\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
|
|
|
The memory used for a general context should be freed by calling:
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B void pcre2_general_context_free(pcre2_general_context *\fIgcontext\fP);
|
|
|
|
.fi
|
|
|
|
.sp
|
2018-06-30 15:13:47 +02:00
|
|
|
If this function is passed a NULL argument, it returns immediately without
|
|
|
|
doing anything.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.\" HTML <a name="compilecontext"></a>
|
|
|
|
.SS "The compile context"
|
|
|
|
.rs
|
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
A compile context is required if you want to provide an external function for
|
|
|
|
stack checking during compilation or to change the default values of any of the
|
|
|
|
following compile-time parameters:
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2014-11-18 19:32:12 +01:00
|
|
|
What \eR matches (Unicode newlines or CR, LF, CRLF only)
|
|
|
|
PCRE2's character tables
|
|
|
|
The newline character sequence
|
|
|
|
The compile time nested parentheses limit
|
2015-12-17 19:44:06 +01:00
|
|
|
The maximum length of the pattern string
|
2017-05-30 12:42:57 +02:00
|
|
|
The extra options bits (none set by default)
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2014-10-20 19:28:49 +02:00
|
|
|
A compile context is also required if you are using custom memory management.
|
2014-09-19 09:43:39 +02:00
|
|
|
If none of these apply, just pass NULL as the context argument of
|
|
|
|
\fIpcre2_compile()\fP.
|
|
|
|
.P
|
|
|
|
A compile context is created, copied, and freed by the following functions:
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B pcre2_compile_context *pcre2_compile_context_create(
|
|
|
|
.B " pcre2_general_context *\fIgcontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B pcre2_compile_context *pcre2_compile_context_copy(
|
|
|
|
.B " pcre2_compile_context *\fIccontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_compile_context_free(pcre2_compile_context *\fIccontext\fP);
|
|
|
|
.fi
|
|
|
|
.sp
|
2014-10-20 19:28:49 +02:00
|
|
|
A compile context is created with default values for its parameters. These can
|
|
|
|
be changed by calling the following functions, which return 0 on success, or
|
2014-09-19 09:43:39 +02:00
|
|
|
PCRE2_ERROR_BADDATA if invalid data is detected.
|
|
|
|
.sp
|
|
|
|
.nf
|
2014-10-01 19:02:33 +02:00
|
|
|
.B int pcre2_set_bsr(pcre2_compile_context *\fIccontext\fP,
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " uint32_t \fIvalue\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
2014-10-20 19:28:49 +02:00
|
|
|
The value must be PCRE2_BSR_ANYCRLF, to specify that \eR matches only CR, LF,
|
|
|
|
or CRLF, or PCRE2_BSR_UNICODE, to specify that \eR matches any Unicode line
|
2014-11-18 19:32:12 +01:00
|
|
|
ending sequence. The value is used by the JIT compiler and by the two
|
|
|
|
interpreted matching functions, \fIpcre2_match()\fP and
|
2014-10-01 19:02:33 +02:00
|
|
|
\fIpcre2_dfa_match()\fP.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_set_character_tables(pcre2_compile_context *\fIccontext\fP,
|
2019-07-28 17:58:24 +02:00
|
|
|
.B " const uint8_t *\fItables\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.fi
|
|
|
|
.sp
|
2019-09-03 16:16:07 +02:00
|
|
|
The value must be the result of a call to \fBpcre2_maketables()\fP, whose only
|
2014-09-19 09:43:39 +02:00
|
|
|
argument is a general context. This function builds a set of character tables
|
|
|
|
in the current locale.
|
|
|
|
.sp
|
|
|
|
.nf
|
2017-05-17 19:55:11 +02:00
|
|
|
.B int pcre2_set_compile_extra_options(pcre2_compile_context *\fIccontext\fP,
|
|
|
|
.B " uint32_t \fIextra_options\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
|
|
|
As PCRE2 has developed, almost all the 32 option bits that are available in
|
|
|
|
the \fIoptions\fP argument of \fBpcre2_compile()\fP have been used up. To avoid
|
2017-05-30 12:42:57 +02:00
|
|
|
running out, the compile context contains a set of extra option bits which are
|
|
|
|
used for some newer, assumed rarer, options. This function sets those bits. It
|
|
|
|
always sets all the bits (either on or off). It does not modify any existing
|
2017-05-17 19:55:11 +02:00
|
|
|
setting. The available options are defined in the section entitled "Extra
|
|
|
|
compile options"
|
|
|
|
.\" HTML <a href="#extracompileoptions">
|
|
|
|
.\" </a>
|
|
|
|
below.
|
|
|
|
.\"
|
|
|
|
.sp
|
|
|
|
.nf
|
2015-11-05 18:33:39 +01:00
|
|
|
.B int pcre2_set_max_pattern_length(pcre2_compile_context *\fIccontext\fP,
|
|
|
|
.B " PCRE2_SIZE \fIvalue\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
This sets a maximum length, in code units, for any pattern string that is
|
|
|
|
compiled with this context. If the pattern is longer, an error is generated.
|
|
|
|
This facility is provided so that applications that accept patterns from
|
|
|
|
external sources can limit their size. The default is the largest number that a
|
|
|
|
PCRE2_SIZE variable can hold, which is effectively unlimited.
|
2015-11-05 18:33:39 +01:00
|
|
|
.sp
|
|
|
|
.nf
|
2014-10-01 19:02:33 +02:00
|
|
|
.B int pcre2_set_newline(pcre2_compile_context *\fIccontext\fP,
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " uint32_t \fIvalue\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
2014-10-20 19:28:49 +02:00
|
|
|
This specifies which characters or character sequences are to be recognized as
|
2014-09-19 09:43:39 +02:00
|
|
|
newlines. The value must be one of PCRE2_NEWLINE_CR (carriage return only),
|
2014-10-20 19:28:49 +02:00
|
|
|
PCRE2_NEWLINE_LF (linefeed only), PCRE2_NEWLINE_CRLF (the two-character
|
2017-05-30 12:42:57 +02:00
|
|
|
sequence CR followed by LF), PCRE2_NEWLINE_ANYCRLF (any of the above),
|
|
|
|
PCRE2_NEWLINE_ANY (any Unicode newline sequence), or PCRE2_NEWLINE_NUL (the
|
2017-05-26 19:14:36 +02:00
|
|
|
NUL character, that is a binary zero).
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2017-03-28 18:34:29 +02:00
|
|
|
A pattern can override the value set in the compile context by starting with a
|
|
|
|
sequence such as (*CRLF). See the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2pattern\fP
|
|
|
|
.\"
|
|
|
|
page for details.
|
|
|
|
.P
|
2017-04-20 18:34:35 +02:00
|
|
|
When a pattern is compiled with the PCRE2_EXTENDED or PCRE2_EXTENDED_MORE
|
2018-08-03 11:38:36 +02:00
|
|
|
option, the newline convention affects the recognition of the end of internal
|
|
|
|
comments starting with #. The value is saved with the compiled pattern for
|
|
|
|
subsequent use by the JIT compiler and by the two interpreted matching
|
|
|
|
functions, \fIpcre2_match()\fP and \fIpcre2_dfa_match()\fP.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_set_parens_nest_limit(pcre2_compile_context *\fIccontext\fP,
|
|
|
|
.B " uint32_t \fIvalue\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
2018-10-17 18:44:22 +02:00
|
|
|
This parameter adjusts the limit, set when PCRE2 is built (default 250), on the
|
2014-09-19 09:43:39 +02:00
|
|
|
depth of parenthesis nesting in a pattern. This limit stops rogue patterns
|
2017-01-16 18:40:47 +01:00
|
|
|
using up too much system stack when being compiled. The limit applies to
|
2016-10-02 18:01:01 +02:00
|
|
|
parentheses of all kinds, not just capturing parentheses.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_set_compile_recursion_guard(pcre2_compile_context *\fIccontext\fP,
|
2014-11-26 17:51:53 +01:00
|
|
|
.B " int (*\fIguard_function\fP)(uint32_t, void *), void *\fIuser_data\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.fi
|
|
|
|
.sp
|
|
|
|
There is at least one application that runs PCRE2 in threads with very limited
|
2014-10-20 19:28:49 +02:00
|
|
|
system stack, where running out of stack is to be avoided at all costs. The
|
2014-09-19 09:43:39 +02:00
|
|
|
parenthesis limit above cannot take account of how much stack is actually
|
2017-04-20 18:34:35 +02:00
|
|
|
available during compilation. For a finer control, you can supply a function
|
|
|
|
that is called whenever \fBpcre2_compile()\fP starts to compile a parenthesized
|
|
|
|
part of a pattern. This function can check the actual stack size (or anything
|
|
|
|
else that it wants to, of course).
|
2014-11-26 17:51:53 +01:00
|
|
|
.P
|
|
|
|
The first argument to the callout function gives the current depth of
|
|
|
|
nesting, and the second is user data that is set up by the last argument of
|
|
|
|
\fBpcre2_set_compile_recursion_guard()\fP. The callout function should return
|
|
|
|
zero if all is well, or non-zero to force an error.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.\" HTML <a name="matchcontext"></a>
|
|
|
|
.SS "The match context"
|
|
|
|
.rs
|
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
A match context is required if you want to:
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
Set up a callout function
|
|
|
|
Set an offset limit for matching an unanchored pattern
|
2017-05-30 12:42:57 +02:00
|
|
|
Change the limit on the amount of heap used when matching
|
2017-03-28 18:34:29 +02:00
|
|
|
Change the backtracking match limit
|
|
|
|
Change the backtracking depth limit
|
|
|
|
Set custom memory management specifically for the match
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2014-10-20 19:28:49 +02:00
|
|
|
If none of these apply, just pass NULL as the context argument of
|
2014-09-19 09:43:39 +02:00
|
|
|
\fBpcre2_match()\fP, \fBpcre2_dfa_match()\fP, or \fBpcre2_jit_match()\fP.
|
|
|
|
.P
|
|
|
|
A match context is created, copied, and freed by the following functions:
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B pcre2_match_context *pcre2_match_context_create(
|
|
|
|
.B " pcre2_general_context *\fIgcontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B pcre2_match_context *pcre2_match_context_copy(
|
|
|
|
.B " pcre2_match_context *\fImcontext\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_match_context_free(pcre2_match_context *\fImcontext\fP);
|
|
|
|
.fi
|
|
|
|
.sp
|
2014-10-20 19:28:49 +02:00
|
|
|
A match context is created with default values for its parameters. These can
|
|
|
|
be changed by calling the following functions, which return 0 on success, or
|
2014-09-19 09:43:39 +02:00
|
|
|
PCRE2_ERROR_BADDATA if invalid data is detected.
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_set_callout(pcre2_match_context *\fImcontext\fP,
|
2014-11-25 18:35:01 +01:00
|
|
|
.B " int (*\fIcallout_function\fP)(pcre2_callout_block *, void *),"
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " void *\fIcallout_data\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
2018-09-18 18:31:30 +02:00
|
|
|
This sets up a callout function for PCRE2 to call at specified points
|
2014-09-19 09:43:39 +02:00
|
|
|
during a matching operation. Details are given in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2callout\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
|
|
|
.sp
|
|
|
|
.nf
|
2018-09-18 18:31:30 +02:00
|
|
|
.B int pcre2_set_substitute_callout(pcre2_match_context *\fImcontext\fP,
|
2018-11-12 17:02:01 +01:00
|
|
|
.B " int (*\fIcallout_function\fP)(pcre2_substitute_callout_block *, void *),"
|
2018-09-18 18:31:30 +02:00
|
|
|
.B " void *\fIcallout_data\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
|
|
|
This sets up a callout function for PCRE2 to call after each substitution
|
|
|
|
made by \fBpcre2_substitute()\fP. Details are given in the section entitled
|
|
|
|
"Creating a new string with substitutions"
|
|
|
|
.\" HTML <a href="#substitutions">
|
|
|
|
.\" </a>
|
|
|
|
below.
|
|
|
|
.\"
|
|
|
|
.sp
|
|
|
|
.nf
|
2015-09-22 18:51:11 +02:00
|
|
|
.B int pcre2_set_offset_limit(pcre2_match_context *\fImcontext\fP,
|
|
|
|
.B " PCRE2_SIZE \fIvalue\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
|
|
|
The \fIoffset_limit\fP parameter limits how far an unanchored search can
|
|
|
|
advance in the subject string. The default value is PCRE2_UNSET. The
|
|
|
|
\fBpcre2_match()\fP and \fBpcre2_dfa_match()\fP functions return
|
|
|
|
PCRE2_ERROR_NOMATCH if a match with a starting point before or at the given
|
2018-01-13 17:53:02 +01:00
|
|
|
offset is not found. The \fBpcre2_substitute()\fP function makes no more
|
2017-10-23 18:57:22 +02:00
|
|
|
substitutions.
|
|
|
|
.P
|
|
|
|
For example, if the pattern /abc/ is matched against "123abc" with an offset
|
2018-12-14 17:10:57 +01:00
|
|
|
limit less than 3, the result is PCRE2_ERROR_NOMATCH. A match can never be
|
2017-10-23 18:57:22 +02:00
|
|
|
found if the \fIstartoffset\fP argument of \fBpcre2_match()\fP,
|
|
|
|
\fBpcre2_dfa_match()\fP, or \fBpcre2_substitute()\fP is greater than the offset
|
|
|
|
limit set in the match context.
|
2015-09-22 18:51:11 +02:00
|
|
|
.P
|
2017-03-28 18:34:29 +02:00
|
|
|
When using this facility, you must set the PCRE2_USE_OFFSET_LIMIT option when
|
|
|
|
calling \fBpcre2_compile()\fP so that when JIT is in use, different code can be
|
2015-09-22 18:51:11 +02:00
|
|
|
compiled. If a match is started with a non-default match limit when
|
|
|
|
PCRE2_USE_OFFSET_LIMIT is not set, an error is generated.
|
|
|
|
.P
|
|
|
|
The offset limit facility can be used to track progress when searching large
|
2017-10-23 18:57:22 +02:00
|
|
|
subject strings or to limit the extent of global substitutions. See also the
|
2017-12-31 18:44:12 +01:00
|
|
|
PCRE2_FIRSTLINE option, which requires a match to start before or at the first
|
|
|
|
newline that follows the start of matching in the subject. If this is set with
|
|
|
|
an offset limit, a match must occur in the first line and also within the
|
|
|
|
offset limit. In other words, whichever limit comes first is used.
|
2015-09-22 18:51:11 +02:00
|
|
|
.sp
|
|
|
|
.nf
|
2017-04-11 13:47:25 +02:00
|
|
|
.B int pcre2_set_heap_limit(pcre2_match_context *\fImcontext\fP,
|
|
|
|
.B " uint32_t \fIvalue\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
2018-06-17 16:13:28 +02:00
|
|
|
The \fIheap_limit\fP parameter specifies, in units of kibibytes (1024 bytes),
|
|
|
|
the maximum amount of heap memory that \fBpcre2_match()\fP may use to hold
|
|
|
|
backtracking information when running an interpretive match. This limit also
|
|
|
|
applies to \fBpcre2_dfa_match()\fP, which may use the heap when processing
|
|
|
|
patterns with a lot of nested pattern recursion or lookarounds or atomic
|
|
|
|
groups. This limit does not apply to matching with the JIT optimization, which
|
|
|
|
has its own memory control arrangements (see the
|
2017-04-11 13:47:25 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2jit\fP
|
|
|
|
.\"
|
2018-04-27 18:48:35 +02:00
|
|
|
documentation for more details). If the limit is reached, the negative error
|
2018-06-17 16:13:28 +02:00
|
|
|
code PCRE2_ERROR_HEAPLIMIT is returned. The default limit can be set when PCRE2
|
|
|
|
is built; if it is not, the default is set very large and is essentially
|
|
|
|
"unlimited".
|
2017-04-11 13:47:25 +02:00
|
|
|
.P
|
|
|
|
A value for the heap limit may also be supplied by an item at the start of a
|
|
|
|
pattern of the form
|
|
|
|
.sp
|
|
|
|
(*LIMIT_HEAP=ddd)
|
|
|
|
.sp
|
|
|
|
where ddd is a decimal number. However, such a setting is ignored unless ddd is
|
|
|
|
less than the limit set by the caller of \fBpcre2_match()\fP or, if no such
|
|
|
|
limit is set, less than the default.
|
|
|
|
.P
|
2018-06-18 16:03:33 +02:00
|
|
|
The \fBpcre2_match()\fP function starts out using a 20KiB vector on the system
|
2017-04-11 13:47:25 +02:00
|
|
|
stack for recording backtracking points. The more nested backtracking points
|
2017-05-30 12:42:57 +02:00
|
|
|
there are (that is, the deeper the search tree), the more memory is needed.
|
|
|
|
Heap memory is used only if the initial vector is too small. If the heap limit
|
|
|
|
is set to a value less than 21 (in particular, zero) no heap memory will be
|
|
|
|
used. In this case, only patterns that do not have a lot of nested backtracking
|
|
|
|
can be successfully processed.
|
2018-04-27 18:48:35 +02:00
|
|
|
.P
|
2018-06-18 18:49:12 +02:00
|
|
|
Similarly, for \fBpcre2_dfa_match()\fP, a vector on the system stack is used
|
|
|
|
when processing pattern recursions, lookarounds, or atomic groups, and only if
|
|
|
|
this is not big enough is heap memory used. In this case, too, setting a value
|
2018-04-27 18:48:35 +02:00
|
|
|
of zero disables the use of the heap.
|
2017-04-11 13:47:25 +02:00
|
|
|
.sp
|
|
|
|
.nf
|
2014-09-19 09:43:39 +02:00
|
|
|
.B int pcre2_set_match_limit(pcre2_match_context *\fImcontext\fP,
|
|
|
|
.B " uint32_t \fIvalue\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
|
|
|
The \fImatch_limit\fP parameter provides a means of preventing PCRE2 from using
|
2017-04-11 13:47:25 +02:00
|
|
|
up too many computing resources when processing patterns that are not going to
|
|
|
|
match, but which have a very large number of possibilities in their search
|
|
|
|
trees. The classic example is a pattern that uses nested unlimited repeats.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2017-03-28 18:34:29 +02:00
|
|
|
There is an internal counter in \fBpcre2_match()\fP that is incremented each
|
|
|
|
time round its main matching loop. If this value reaches the match limit,
|
|
|
|
\fBpcre2_match()\fP returns the negative value PCRE2_ERROR_MATCHLIMIT. This has
|
|
|
|
the effect of limiting the amount of backtracking that can take place. For
|
2014-09-19 09:43:39 +02:00
|
|
|
patterns that are not anchored, the count restarts from zero for each position
|
2017-05-30 12:42:57 +02:00
|
|
|
in the subject string. This limit also applies to \fBpcre2_dfa_match()\fP,
|
|
|
|
though the counting is done in a different way.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2014-11-21 17:45:06 +01:00
|
|
|
When \fBpcre2_match()\fP is called with a pattern that was successfully
|
2014-11-18 19:32:12 +01:00
|
|
|
processed by \fBpcre2_jit_compile()\fP, the way in which matching is executed
|
|
|
|
is entirely different. However, there is still the possibility of runaway
|
|
|
|
matching that goes on for a very long time, and so the \fImatch_limit\fP value
|
|
|
|
is also used in this case (but in a different way) to limit how long the
|
|
|
|
matching can continue.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
The default value for the limit can be set when PCRE2 is built; the default
|
2017-03-28 18:34:29 +02:00
|
|
|
default is 10 million, which handles all but the most extreme cases. A value
|
2014-09-19 09:43:39 +02:00
|
|
|
for the match limit may also be supplied by an item at the start of a pattern
|
|
|
|
of the form
|
|
|
|
.sp
|
|
|
|
(*LIMIT_MATCH=ddd)
|
|
|
|
.sp
|
|
|
|
where ddd is a decimal number. However, such a setting is ignored unless ddd is
|
2017-05-30 12:42:57 +02:00
|
|
|
less than the limit set by the caller of \fBpcre2_match()\fP or
|
|
|
|
\fBpcre2_dfa_match()\fP or, if no such limit is set, less than the default.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
.nf
|
2017-03-28 18:34:29 +02:00
|
|
|
.B int pcre2_set_depth_limit(pcre2_match_context *\fImcontext\fP,
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " uint32_t \fIvalue\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
This parameter limits the depth of nested backtracking in \fBpcre2_match()\fP.
|
2017-05-30 12:42:57 +02:00
|
|
|
Each time a nested backtracking point is passed, a new memory "frame" is used
|
2017-03-28 18:34:29 +02:00
|
|
|
to remember the state of matching at that point. Thus, this parameter
|
2017-04-11 13:47:25 +02:00
|
|
|
indirectly limits the amount of memory that is used in a match. However,
|
|
|
|
because the size of each memory "frame" depends on the number of capturing
|
|
|
|
parentheses, the actual memory limit varies from pattern to pattern. This limit
|
|
|
|
was more useful in versions before 10.30, where function recursion was used for
|
|
|
|
backtracking.
|
|
|
|
.P
|
|
|
|
The depth limit is not relevant, and is ignored, when matching is done using
|
|
|
|
JIT compiled code. However, it is supported by \fBpcre2_dfa_match()\fP, which
|
2018-04-27 18:48:35 +02:00
|
|
|
uses it to limit the depth of nested internal recursive function calls that
|
|
|
|
implement atomic groups, lookaround assertions, and pattern recursions. This
|
2018-06-17 16:13:28 +02:00
|
|
|
limits, indirectly, the amount of system stack that is used. It was more useful
|
2018-04-27 18:48:35 +02:00
|
|
|
in versions before 10.32, when stack memory was used for local workspace
|
|
|
|
vectors for recursive function calls. From version 10.32, only local variables
|
|
|
|
are allocated on the stack and as each call uses only a few hundred bytes, even
|
|
|
|
a small stack can support quite a lot of recursion.
|
|
|
|
.P
|
|
|
|
If the depth of internal recursive function calls is great enough, local
|
|
|
|
workspace vectors are allocated on the heap from version 10.32 onwards, so the
|
|
|
|
depth limit also indirectly limits the amount of heap memory that is used. A
|
|
|
|
recursive pattern such as /(.(?2))((?1)|)/, when matched to a very long string
|
|
|
|
using \fBpcre2_dfa_match()\fP, can use a great deal of memory. However, it is
|
|
|
|
probably better to limit heap usage directly by calling
|
|
|
|
\fBpcre2_set_heap_limit()\fP.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2018-06-18 18:49:12 +02:00
|
|
|
The default value for the depth limit can be set when PCRE2 is built; if it is
|
2018-06-17 16:13:28 +02:00
|
|
|
not, the default is set to the same value as the default for the match limit.
|
|
|
|
If the limit is exceeded, \fBpcre2_match()\fP or \fBpcre2_dfa_match()\fP
|
|
|
|
returns PCRE2_ERROR_DEPTHLIMIT. A value for the depth limit may also be
|
|
|
|
supplied by an item at the start of a pattern of the form
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
(*LIMIT_DEPTH=ddd)
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
where ddd is a decimal number. However, such a setting is ignored unless ddd is
|
2016-12-23 12:04:51 +01:00
|
|
|
less than the limit set by the caller of \fBpcre2_match()\fP or
|
|
|
|
\fBpcre2_dfa_match()\fP or, if no such limit is set, less than the default.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH "CHECKING BUILD-TIME OPTIONS"
|
|
|
|
.rs
|
|
|
|
.sp
|
2014-10-15 18:44:12 +02:00
|
|
|
.B int pcre2_config(uint32_t \fIwhat\fP, void *\fIwhere\fP);
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2020-03-20 19:09:59 +01:00
|
|
|
The function \fBpcre2_config()\fP makes it possible for a PCRE2 client to find
|
|
|
|
the value of certain configuration parameters and to discover which optional
|
|
|
|
features have been compiled into the PCRE2 library. The
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2build\fP
|
|
|
|
.\"
|
2020-03-20 19:09:59 +01:00
|
|
|
documentation has more details about these features.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
The first argument for \fBpcre2_config()\fP specifies which information is
|
|
|
|
required. The second argument is a pointer to memory into which the information
|
2014-10-16 18:49:23 +02:00
|
|
|
is placed. If NULL is passed, the function returns the amount of memory that is
|
2014-10-15 18:44:12 +02:00
|
|
|
needed for the requested information. For calls that return numerical values,
|
2014-10-16 18:49:23 +02:00
|
|
|
the value is in bytes; when requesting these values, \fIwhere\fP should point
|
2014-10-20 19:28:49 +02:00
|
|
|
to appropriately aligned memory. For calls that return strings, the required
|
2014-10-16 18:49:23 +02:00
|
|
|
length is given in code units, not counting the terminating zero.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2014-10-16 18:49:23 +02:00
|
|
|
When requesting information, the returned value from \fBpcre2_config()\fP is
|
|
|
|
non-negative on success, or the negative error code PCRE2_ERROR_BADOPTION if
|
|
|
|
the value in the first argument is not recognized. The following information is
|
|
|
|
available:
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_BSR
|
|
|
|
.sp
|
2014-11-25 12:55:07 +01:00
|
|
|
The output is a uint32_t integer whose value indicates what character
|
|
|
|
sequences the \eR escape sequence matches by default. A value of
|
|
|
|
PCRE2_BSR_UNICODE means that \eR matches any Unicode line ending sequence; a
|
|
|
|
value of PCRE2_BSR_ANYCRLF means that \eR matches only CR, LF, or CRLF. The
|
|
|
|
default can be overridden when a pattern is compiled.
|
2017-09-16 13:39:38 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_COMPILED_WIDTHS
|
|
|
|
.sp
|
|
|
|
The output is a uint32_t integer whose lower bits indicate which code unit
|
2017-09-17 18:56:41 +02:00
|
|
|
widths were selected when PCRE2 was built. The 1-bit indicates 8-bit support,
|
2017-09-16 13:39:38 +02:00
|
|
|
and the 2-bit and 4-bit indicate 16-bit and 32-bit support, respectively.
|
2017-03-28 18:34:29 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_DEPTHLIMIT
|
|
|
|
.sp
|
|
|
|
The output is a uint32_t integer that gives the default limit for the depth of
|
2018-04-27 18:48:35 +02:00
|
|
|
nested backtracking in \fBpcre2_match()\fP or the depth of nested recursions,
|
|
|
|
lookarounds, and atomic groups in \fBpcre2_dfa_match()\fP. Further details are
|
|
|
|
given with \fBpcre2_set_depth_limit()\fP above.
|
2017-04-11 13:47:25 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_HEAPLIMIT
|
|
|
|
.sp
|
2018-06-17 16:13:28 +02:00
|
|
|
The output is a uint32_t integer that gives, in kibibytes, the default limit
|
2018-06-18 18:49:12 +02:00
|
|
|
for the amount of heap memory used by \fBpcre2_match()\fP or
|
2018-04-27 18:48:35 +02:00
|
|
|
\fBpcre2_dfa_match()\fP. Further details are given with
|
|
|
|
\fBpcre2_set_heap_limit()\fP above.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_JIT
|
|
|
|
.sp
|
2014-11-25 12:55:07 +01:00
|
|
|
The output is a uint32_t integer that is set to one if support for just-in-time
|
2014-09-19 09:43:39 +02:00
|
|
|
compiling is available; otherwise it is set to zero.
|
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_JITTARGET
|
|
|
|
.sp
|
2014-10-16 18:49:23 +02:00
|
|
|
The \fIwhere\fP argument should point to a buffer that is at least 48 code
|
2014-11-18 19:32:12 +01:00
|
|
|
units long. (The exact length required can be found by calling
|
2014-10-16 18:49:23 +02:00
|
|
|
\fBpcre2_config()\fP with \fBwhere\fP set to NULL.) The buffer is filled with a
|
|
|
|
string that contains the name of the architecture for which the JIT compiler is
|
|
|
|
configured, for example "x86 32bit (little endian + unaligned)". If JIT support
|
2014-11-08 17:09:24 +01:00
|
|
|
is not available, PCRE2_ERROR_BADOPTION is returned, otherwise the number of
|
|
|
|
code units used is returned. This is the length of the string, plus one unit
|
|
|
|
for the terminating zero.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_LINKSIZE
|
|
|
|
.sp
|
2014-11-25 12:55:07 +01:00
|
|
|
The output is a uint32_t integer that contains the number of bytes used for
|
|
|
|
internal linkage in compiled regular expressions. When PCRE2 is configured, the
|
|
|
|
value can be set to 2, 3, or 4, with the default being 2. This is the value
|
|
|
|
that is returned by \fBpcre2_config()\fP. However, when the 16-bit library is
|
|
|
|
compiled, a value of 3 is rounded up to 4, and when the 32-bit library is
|
|
|
|
compiled, internal linkages always use 4 bytes, so the configured value is not
|
|
|
|
relevant.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
The default value of 2 for the 8-bit and 16-bit libraries is sufficient for all
|
|
|
|
but the most massive patterns, since it allows the size of the compiled pattern
|
2018-06-18 16:03:33 +02:00
|
|
|
to be up to 65535 code units. Larger values allow larger regular expressions to
|
2014-09-19 09:43:39 +02:00
|
|
|
be compiled by those two libraries, but at the expense of slower matching.
|
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_MATCHLIMIT
|
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
The output is a uint32_t integer that gives the default match limit for
|
|
|
|
\fBpcre2_match()\fP. Further details are given with
|
|
|
|
\fBpcre2_set_match_limit()\fP above.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_NEWLINE
|
|
|
|
.sp
|
2014-11-25 12:55:07 +01:00
|
|
|
The output is a uint32_t integer whose value specifies the default character
|
|
|
|
sequence that is recognized as meaning "newline". The values are:
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2014-11-18 19:32:12 +01:00
|
|
|
PCRE2_NEWLINE_CR Carriage return (CR)
|
|
|
|
PCRE2_NEWLINE_LF Linefeed (LF)
|
|
|
|
PCRE2_NEWLINE_CRLF Carriage return, linefeed (CRLF)
|
|
|
|
PCRE2_NEWLINE_ANY Any Unicode line ending
|
|
|
|
PCRE2_NEWLINE_ANYCRLF Any of CR, LF, or CRLF
|
2017-05-30 12:42:57 +02:00
|
|
|
PCRE2_NEWLINE_NUL The NUL character (binary zero)
|
2014-10-20 19:28:49 +02:00
|
|
|
.sp
|
2014-09-19 09:43:39 +02:00
|
|
|
The default should normally correspond to the standard sequence for your
|
|
|
|
operating system.
|
2017-09-16 13:39:38 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_NEVER_BACKSLASH_C
|
|
|
|
.sp
|
2017-09-17 18:56:41 +02:00
|
|
|
The output is a uint32_t integer that is set to one if the use of \eC was
|
|
|
|
permanently disabled when PCRE2 was built; otherwise it is set to zero.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_PARENSLIMIT
|
|
|
|
.sp
|
2014-11-25 12:55:07 +01:00
|
|
|
The output is a uint32_t integer that gives the maximum depth of nesting
|
2014-09-19 09:43:39 +02:00
|
|
|
of parentheses (of any kind) in a pattern. This limit is imposed to cap the
|
|
|
|
amount of system stack used when a pattern is compiled. It is specified when
|
|
|
|
PCRE2 is built; the default is 250. This limit does not take into account the
|
|
|
|
stack that may already be used by the calling application. For finer control
|
|
|
|
over compilation stack usage, see \fBpcre2_set_compile_recursion_guard()\fP.
|
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_STACKRECURSE
|
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
This parameter is obsolete and should not be used in new code. The output is a
|
|
|
|
uint32_t integer that is always set to zero.
|
2020-03-20 19:09:59 +01:00
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_TABLES_LENGTH
|
|
|
|
.sp
|
2020-04-15 18:34:36 +02:00
|
|
|
The output is a uint32_t integer that gives the length of PCRE2's character
|
2020-03-20 19:09:59 +01:00
|
|
|
processing tables in bytes. For details of these tables see the
|
|
|
|
.\" HTML <a href="#localesupport">
|
|
|
|
.\" </a>
|
|
|
|
section on locale support
|
|
|
|
.\"
|
|
|
|
below.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_UNICODE_VERSION
|
2014-10-20 19:28:49 +02:00
|
|
|
.sp
|
2014-09-19 09:43:39 +02:00
|
|
|
The \fIwhere\fP argument should point to a buffer that is at least 24 code
|
2014-11-18 19:32:12 +01:00
|
|
|
units long. (The exact length required can be found by calling
|
2014-10-16 18:49:23 +02:00
|
|
|
\fBpcre2_config()\fP with \fBwhere\fP set to NULL.) If PCRE2 has been compiled
|
|
|
|
without Unicode support, the buffer is filled with the text "Unicode not
|
2015-07-17 17:44:51 +02:00
|
|
|
supported". Otherwise, the Unicode version string (for example, "8.0.0") is
|
2014-11-08 17:09:24 +01:00
|
|
|
inserted. The number of code units used is returned. This is the length of the
|
|
|
|
string plus one unit for the terminating zero.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_UNICODE
|
|
|
|
.sp
|
2014-11-25 12:55:07 +01:00
|
|
|
The output is a uint32_t integer that is set to one if Unicode support is
|
|
|
|
available; otherwise it is set to zero. Unicode support implies UTF support.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_CONFIG_VERSION
|
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
The \fIwhere\fP argument should point to a buffer that is at least 24 code
|
2014-11-18 19:32:12 +01:00
|
|
|
units long. (The exact length required can be found by calling
|
2014-10-16 18:49:23 +02:00
|
|
|
\fBpcre2_config()\fP with \fBwhere\fP set to NULL.) The buffer is filled with
|
2014-11-11 17:51:07 +01:00
|
|
|
the PCRE2 version string, zero-terminated. The number of code units used is
|
|
|
|
returned. This is the length of the string plus one unit for the terminating
|
2014-11-08 17:09:24 +01:00
|
|
|
zero.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
2014-10-19 17:30:48 +02:00
|
|
|
.\" HTML <a name="compiling"></a>
|
2014-09-19 09:43:39 +02:00
|
|
|
.SH "COMPILING A PATTERN"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B pcre2_code *pcre2_compile(PCRE2_SPTR \fIpattern\fP, PCRE2_SIZE \fIlength\fP,
|
|
|
|
.B " uint32_t \fIoptions\fP, int *\fIerrorcode\fP, PCRE2_SIZE *\fIerroroffset,\fP"
|
|
|
|
.B " pcre2_compile_context *\fIccontext\fP);"
|
|
|
|
.sp
|
2015-07-29 10:03:34 +02:00
|
|
|
.B void pcre2_code_free(pcre2_code *\fIcode\fP);
|
2016-02-26 19:26:17 +01:00
|
|
|
.sp
|
|
|
|
.B pcre2_code *pcre2_code_copy(const pcre2_code *\fIcode\fP);
|
2016-11-22 16:37:02 +01:00
|
|
|
.sp
|
|
|
|
.B pcre2_code *pcre2_code_copy_with_tables(const pcre2_code *\fIcode\fP);
|
2014-09-19 09:43:39 +02:00
|
|
|
.fi
|
|
|
|
.P
|
2014-11-18 19:32:12 +01:00
|
|
|
The \fBpcre2_compile()\fP function compiles a pattern into an internal form.
|
2017-09-17 18:56:41 +02:00
|
|
|
The pattern is defined by a pointer to a string of code units and a length (in
|
|
|
|
code units). If the pattern is zero-terminated, the length can be specified as
|
2014-11-18 19:32:12 +01:00
|
|
|
PCRE2_ZERO_TERMINATED. The function returns a pointer to a block of memory that
|
2016-06-17 13:30:27 +02:00
|
|
|
contains the compiled pattern and related data, or NULL if an error occurred.
|
2016-02-26 19:26:17 +01:00
|
|
|
.P
|
|
|
|
If the compile context argument \fIccontext\fP is NULL, memory for the compiled
|
|
|
|
pattern is obtained by calling \fBmalloc()\fP. Otherwise, it is obtained from
|
|
|
|
the same memory function that was used for the compile context. The caller must
|
|
|
|
free the memory by calling \fBpcre2_code_free()\fP when it is no longer needed.
|
2018-08-13 13:57:09 +02:00
|
|
|
If \fBpcre2_code_free()\fP is called with a NULL argument, it returns
|
2018-06-28 18:26:03 +02:00
|
|
|
immediately, without doing anything.
|
2016-02-26 19:26:17 +01:00
|
|
|
.P
|
2016-06-05 18:05:34 +02:00
|
|
|
The function \fBpcre2_code_copy()\fP makes a copy of the compiled code in new
|
|
|
|
memory, using the same memory allocator as was used for the original. However,
|
2016-02-26 19:26:17 +01:00
|
|
|
if the code has been processed by the JIT compiler (see
|
|
|
|
.\" HTML <a href="#jitcompiling">
|
|
|
|
.\" </a>
|
|
|
|
below),
|
|
|
|
.\"
|
2016-06-05 18:05:34 +02:00
|
|
|
the JIT information cannot be copied (because it is position-dependent).
|
|
|
|
The new copy can initially be used only for non-JIT matching, though it can be
|
2018-08-13 13:57:09 +02:00
|
|
|
passed to \fBpcre2_jit_compile()\fP if required. If \fBpcre2_code_copy()\fP is
|
2018-06-28 18:26:03 +02:00
|
|
|
called with a NULL argument, it returns NULL.
|
2016-11-22 16:37:02 +01:00
|
|
|
.P
|
|
|
|
The \fBpcre2_code_copy()\fP function provides a way for individual threads in a
|
2017-01-16 18:40:47 +01:00
|
|
|
multithreaded application to acquire a private copy of shared compiled code.
|
|
|
|
However, it does not make a copy of the character tables used by the compiled
|
2016-11-22 16:37:02 +01:00
|
|
|
pattern; the new pattern code points to the same tables as the original code.
|
|
|
|
(See
|
|
|
|
.\" HTML <a href="#jitcompiling">
|
|
|
|
.\" </a>
|
|
|
|
"Locale Support"
|
|
|
|
.\"
|
|
|
|
below for details of these character tables.) In many applications the same
|
2017-01-16 18:40:47 +01:00
|
|
|
tables are used throughout, so this behaviour is appropriate. Nevertheless,
|
|
|
|
there are occasions when a copy of a compiled pattern and the relevant tables
|
|
|
|
are needed. The \fBpcre2_code_copy_with_tables()\fP provides this facility.
|
|
|
|
Copies of both the code and the tables are made, with the new code pointing to
|
2016-11-22 16:37:02 +01:00
|
|
|
the new tables. The memory for the new tables is automatically freed when
|
2018-06-28 18:26:03 +02:00
|
|
|
\fBpcre2_code_free()\fP is called for the new copy of the compiled code. If
|
2019-02-12 18:50:19 +01:00
|
|
|
\fBpcre2_code_copy_with_tables()\fP is called with a NULL argument, it returns
|
2018-06-28 18:26:03 +02:00
|
|
|
NULL.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2014-12-14 18:17:06 +01:00
|
|
|
NOTE: When one of the matching functions is called, pointers to the compiled
|
|
|
|
pattern and the subject string are set in the match data block so that they can
|
2018-10-19 17:31:16 +02:00
|
|
|
be referenced by the substring extraction functions after a successful match.
|
|
|
|
After running a match, you must not free a compiled pattern or a subject string
|
|
|
|
until after all operations on the
|
2014-12-14 18:17:06 +01:00
|
|
|
.\" HTML <a href="#matchdatablock">
|
|
|
|
.\" </a>
|
2014-12-19 10:55:25 +01:00
|
|
|
match data block
|
2014-12-14 18:17:06 +01:00
|
|
|
.\"
|
2019-03-04 19:07:04 +01:00
|
|
|
have taken place, unless, in the case of the subject string, you have used the
|
2018-10-17 10:33:38 +02:00
|
|
|
PCRE2_COPY_MATCHED_SUBJECT option, which is described in the section entitled
|
|
|
|
"Option bits for \fBpcre2_match()\fP"
|
|
|
|
.\" HTML <a href="#matchoptions>">
|
|
|
|
.\" </a>
|
|
|
|
below.
|
|
|
|
.\"
|
2014-12-14 18:17:06 +01:00
|
|
|
.P
|
2016-02-26 19:26:17 +01:00
|
|
|
The \fIoptions\fP argument for \fBpcre2_compile()\fP contains various bit
|
2019-02-12 18:50:19 +01:00
|
|
|
settings that affect the compilation. It should be zero if none of them are
|
2016-02-26 19:26:17 +01:00
|
|
|
required. The available options are described below. Some of them (in
|
|
|
|
particular, those that are compatible with Perl, but some others as well) can
|
|
|
|
also be set and unset from within the pattern (see the detailed description in
|
|
|
|
the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2pattern\fP
|
|
|
|
.\"
|
2014-10-20 19:28:49 +02:00
|
|
|
documentation).
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
For those options that can be different in different parts of the pattern, the
|
|
|
|
contents of the \fIoptions\fP argument specifies their settings at the start of
|
2017-04-04 19:09:33 +02:00
|
|
|
compilation. The PCRE2_ANCHORED, PCRE2_ENDANCHORED, and PCRE2_NO_UTF_CHECK
|
|
|
|
options can be set at the time of matching as well as at compile time.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2019-02-12 18:50:19 +01:00
|
|
|
Some additional options and less frequently required compile-time parameters
|
|
|
|
(for example, the newline setting) can be provided in a compile context (as
|
|
|
|
described
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HTML <a href="#compilecontext">
|
|
|
|
.\" </a>
|
|
|
|
above).
|
|
|
|
.\"
|
|
|
|
.P
|
|
|
|
If \fIerrorcode\fP or \fIerroroffset\fP is NULL, \fBpcre2_compile()\fP returns
|
2016-06-17 13:30:27 +02:00
|
|
|
NULL immediately. Otherwise, the variables to which these point are set to an
|
|
|
|
error code and an offset (number of code units) within the pattern,
|
|
|
|
respectively, when \fBpcre2_compile()\fP returns NULL because a compilation
|
|
|
|
error has occurred. The values are not defined when compilation is successful
|
2017-01-16 18:40:47 +01:00
|
|
|
and \fBpcre2_compile()\fP returns a non-NULL value.
|
2016-10-02 18:01:01 +02:00
|
|
|
.P
|
2017-09-17 18:56:41 +02:00
|
|
|
There are nearly 100 positive error codes that \fBpcre2_compile()\fP may return
|
|
|
|
if it finds an error in the pattern. There are also some negative error codes
|
2019-05-24 19:15:48 +02:00
|
|
|
that are used for invalid UTF strings when validity checking is in force. These
|
|
|
|
are the same as given by \fBpcre2_match()\fP and \fBpcre2_dfa_match()\fP, and
|
|
|
|
are described in the
|
2017-09-17 18:56:41 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2unicode\fP
|
|
|
|
.\"
|
2019-05-24 19:15:48 +02:00
|
|
|
documentation. There is no separate documentation for the positive error codes,
|
|
|
|
because the textual error messages that are obtained by calling the
|
2017-09-17 18:56:41 +02:00
|
|
|
\fBpcre2_get_error_message()\fP function (see "Obtaining a textual error
|
2016-06-17 13:30:27 +02:00
|
|
|
message"
|
|
|
|
.\" HTML <a href="#geterrormessage">
|
|
|
|
.\" </a>
|
|
|
|
below)
|
|
|
|
.\"
|
2017-09-17 18:56:41 +02:00
|
|
|
should be self-explanatory. Macro names starting with PCRE2_ERROR_ are defined
|
|
|
|
for both positive and negative error codes in \fBpcre2.h\fP.
|
|
|
|
.P
|
|
|
|
The value returned in \fIerroroffset\fP is an indication of where in the
|
|
|
|
pattern the error occurred. It is not necessarily the furthest point in the
|
|
|
|
pattern that was read. For example, after the error "lookbehind assertion is
|
|
|
|
not fixed length", the error offset points to the start of the failing
|
|
|
|
assertion. For an invalid UTF-8 or UTF-16 string, the offset is that of the
|
|
|
|
first code unit of the failing character.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
Some errors are not detected until the whole pattern has been scanned; in these
|
|
|
|
cases, the offset passed back is the length of the pattern. Note that the
|
|
|
|
offset is in code units, not characters, even in a UTF mode. It may sometimes
|
|
|
|
point into the middle of a UTF-8 or UTF-16 character.
|
|
|
|
.P
|
|
|
|
This code fragment shows a typical straightforward call to
|
|
|
|
\fBpcre2_compile()\fP:
|
|
|
|
.sp
|
|
|
|
pcre2_code *re;
|
|
|
|
PCRE2_SIZE erroffset;
|
2014-10-20 19:28:49 +02:00
|
|
|
int errorcode;
|
2014-09-19 09:43:39 +02:00
|
|
|
re = pcre2_compile(
|
|
|
|
"^A.*Z", /* the pattern */
|
2014-10-20 19:28:49 +02:00
|
|
|
PCRE2_ZERO_TERMINATED, /* the pattern is zero-terminated */
|
2014-09-19 09:43:39 +02:00
|
|
|
0, /* default options */
|
|
|
|
&errorcode, /* for error code */
|
|
|
|
&erroffset, /* for error offset */
|
|
|
|
NULL); /* no compile context */
|
|
|
|
.sp
|
2019-02-12 18:50:19 +01:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.SS "Main compile options"
|
|
|
|
.rs
|
|
|
|
.sp
|
2014-09-19 09:43:39 +02:00
|
|
|
The following names for option bits are defined in the \fBpcre2.h\fP header
|
|
|
|
file:
|
|
|
|
.sp
|
|
|
|
PCRE2_ANCHORED
|
|
|
|
.sp
|
|
|
|
If this bit is set, the pattern is forced to be "anchored", that is, it is
|
|
|
|
constrained to match only at the first matching point in the string that is
|
|
|
|
being searched (the "subject string"). This effect can also be achieved by
|
|
|
|
appropriate constructs in the pattern itself, which is the only way to do it in
|
|
|
|
Perl.
|
|
|
|
.sp
|
|
|
|
PCRE2_ALLOW_EMPTY_CLASS
|
|
|
|
.sp
|
2014-10-20 19:28:49 +02:00
|
|
|
By default, for compatibility with Perl, a closing square bracket that
|
|
|
|
immediately follows an opening one is treated as a data character for the
|
|
|
|
class. When PCRE2_ALLOW_EMPTY_CLASS is set, it terminates the class, which
|
|
|
|
therefore contains no characters and so can never match.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ALT_BSUX
|
|
|
|
.sp
|
2014-10-20 19:28:49 +02:00
|
|
|
This option request alternative handling of three escape sequences, which
|
2014-09-19 09:43:39 +02:00
|
|
|
makes PCRE2's behaviour more like ECMAscript (aka JavaScript). When it is set:
|
|
|
|
.P
|
|
|
|
(1) \eU matches an upper case "U" character; by default \eU causes a compile
|
|
|
|
time error (Perl uses \eU to upper case subsequent characters).
|
|
|
|
.P
|
|
|
|
(2) \eu matches a lower case "u" character unless it is followed by four
|
|
|
|
hexadecimal digits, in which case the hexadecimal number defines the code point
|
|
|
|
to match. By default, \eu causes a compile time error (Perl uses it to upper
|
|
|
|
case the following character).
|
|
|
|
.P
|
|
|
|
(3) \ex matches a lower case "x" character unless it is followed by two
|
|
|
|
hexadecimal digits, in which case the hexadecimal number defines the code point
|
|
|
|
to match. By default, as in Perl, a hexadecimal number is always expected after
|
|
|
|
\ex, but it may have zero, one, or two digits (so, for example, \exz matches a
|
|
|
|
binary zero character followed by z).
|
2019-02-12 18:50:19 +01:00
|
|
|
.P
|
|
|
|
ECMAscript 6 added additional functionality to \eu. This can be accessed using
|
|
|
|
the PCRE2_EXTRA_ALT_BSUX extra option (see "Extra compile options"
|
|
|
|
.\" HTML <a href="#extracompileoptions">
|
|
|
|
.\" </a>
|
|
|
|
below).
|
|
|
|
.\"
|
2019-03-04 19:07:04 +01:00
|
|
|
Note that this alternative escape handling applies only to patterns. Neither of
|
|
|
|
these options affects the processing of replacement strings passed to
|
2019-02-12 18:50:19 +01:00
|
|
|
\fBpcre2_substitute()\fP.
|
2015-04-22 19:39:25 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ALT_CIRCUMFLEX
|
2015-06-18 18:39:25 +02:00
|
|
|
.sp
|
2015-04-22 19:39:25 +02:00
|
|
|
In multiline mode (when PCRE2_MULTILINE is set), the circumflex metacharacter
|
|
|
|
matches at the start of the subject (unless PCRE2_NOTBOL is set), and also
|
|
|
|
after any internal newline. However, it does not match after a newline at the
|
|
|
|
end of the subject, for compatibility with Perl. If you want a multiline
|
|
|
|
circumflex also to match after a terminating newline, you must set
|
|
|
|
PCRE2_ALT_CIRCUMFLEX.
|
2015-08-30 19:47:36 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ALT_VERBNAMES
|
|
|
|
.sp
|
|
|
|
By default, for compatibility with Perl, the name in any verb sequence such as
|
|
|
|
(*MARK:NAME) is any sequence of characters that does not include a closing
|
|
|
|
parenthesis. The name is not processed in any way, and it is not possible to
|
|
|
|
include a closing parenthesis in the name. However, if the PCRE2_ALT_VERBNAMES
|
|
|
|
option is set, normal backslash processing is applied to verb names and only an
|
2015-09-01 19:32:42 +02:00
|
|
|
unescaped closing parenthesis terminates the name. A closing parenthesis can be
|
2017-05-30 12:42:57 +02:00
|
|
|
included in a name either as \e) or between \eQ and \eE. If the PCRE2_EXTENDED
|
2018-08-03 11:38:36 +02:00
|
|
|
or PCRE2_EXTENDED_MORE option is set with PCRE2_ALT_VERBNAMES, unescaped
|
|
|
|
whitespace in verb names is skipped and #-comments are recognized, exactly as
|
|
|
|
in the rest of the pattern.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_AUTO_CALLOUT
|
|
|
|
.sp
|
|
|
|
If this bit is set, \fBpcre2_compile()\fP automatically inserts callout items,
|
2016-10-02 18:01:01 +02:00
|
|
|
all with number 255, before each pattern item, except immediately before or
|
2017-03-28 18:34:29 +02:00
|
|
|
after an explicit callout in the pattern. For discussion of the callout
|
|
|
|
facility, see the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2callout\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
|
|
|
.sp
|
|
|
|
PCRE2_CASELESS
|
|
|
|
.sp
|
|
|
|
If this bit is set, letters in the pattern match both upper and lower case
|
|
|
|
letters in the subject. It is equivalent to Perl's /i option, and it can be
|
2020-04-15 18:34:36 +02:00
|
|
|
changed within a pattern by a (?i) option setting. If either PCRE2_UTF or
|
2020-02-24 17:35:15 +01:00
|
|
|
PCRE2_UCP is set, Unicode properties are used for all characters with more than
|
|
|
|
one other case, and for all characters whose code points are greater than
|
2020-10-05 18:52:39 +02:00
|
|
|
U+007F. Note that there are two ASCII characters, K and S, that, in addition to
|
|
|
|
their lower case ASCII equivalents, are case-equivalent with U+212A (Kelvin
|
|
|
|
sign) and U+017F (long S) respectively. For lower valued characters with only
|
|
|
|
one other case, a lookup table is used for speed. When neither PCRE2_UTF nor
|
|
|
|
PCRE2_UCP is set, a lookup table is used for all code points less than 256, and
|
|
|
|
higher code points (available only in 16-bit or 32-bit mode) are treated as not
|
|
|
|
having another case.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_DOLLAR_ENDONLY
|
|
|
|
.sp
|
|
|
|
If this bit is set, a dollar metacharacter in the pattern matches only at the
|
|
|
|
end of the subject string. Without this option, a dollar also matches
|
|
|
|
immediately before a newline at the end of the string (but not before any other
|
|
|
|
newlines). The PCRE2_DOLLAR_ENDONLY option is ignored if PCRE2_MULTILINE is
|
|
|
|
set. There is no equivalent to this option in Perl, and no way to set it within
|
|
|
|
a pattern.
|
|
|
|
.sp
|
|
|
|
PCRE2_DOTALL
|
|
|
|
.sp
|
|
|
|
If this bit is set, a dot metacharacter in the pattern matches any character,
|
|
|
|
including one that indicates a newline. However, it only ever matches one
|
|
|
|
character, even if newlines are coded as CRLF. Without this option, a dot does
|
|
|
|
not match when the current position in the subject is at a newline. This option
|
|
|
|
is equivalent to Perl's /s option, and it can be changed within a pattern by a
|
|
|
|
(?s) option setting. A negative class such as [^a] always matches newline
|
2018-07-27 18:30:40 +02:00
|
|
|
characters, and the \eN escape sequence always matches a non-newline character,
|
|
|
|
independent of the setting of PCRE2_DOTALL.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_DUPNAMES
|
|
|
|
.sp
|
2019-02-06 19:11:36 +01:00
|
|
|
If this bit is set, names used to identify capture groups need not be unique.
|
|
|
|
This can be helpful for certain types of pattern when it is known that only one
|
|
|
|
instance of the named group can ever be matched. There are more details of
|
|
|
|
named capture groups below; see also the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2pattern\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
2017-04-04 19:09:33 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ENDANCHORED
|
|
|
|
.sp
|
|
|
|
If this bit is set, the end of any pattern match must be right at the end of
|
2017-05-30 12:42:57 +02:00
|
|
|
the string being searched (the "subject string"). If the pattern match
|
|
|
|
succeeds by reaching (*ACCEPT), but does not reach the end of the subject, the
|
|
|
|
match fails at the current starting point. For unanchored patterns, a new match
|
|
|
|
is then tried at the next starting point. However, if the match succeeds by
|
|
|
|
reaching the end of the pattern, but not the end of the subject, backtracking
|
2017-04-14 14:55:45 +02:00
|
|
|
occurs and an alternative match may be found. Consider these two patterns:
|
|
|
|
.sp
|
|
|
|
.(*ACCEPT)|..
|
|
|
|
.|..
|
|
|
|
.sp
|
|
|
|
If matched against "abc" with PCRE2_ENDANCHORED set, the first matches "c"
|
|
|
|
whereas the second matches "bc". The effect of PCRE2_ENDANCHORED can also be
|
2017-04-04 19:09:33 +02:00
|
|
|
achieved by appropriate constructs in the pattern itself, which is the only way
|
|
|
|
to do it in Perl.
|
2017-04-14 14:55:45 +02:00
|
|
|
.P
|
2017-05-30 12:42:57 +02:00
|
|
|
For DFA matching with \fBpcre2_dfa_match()\fP, PCRE2_ENDANCHORED applies only
|
2017-04-14 14:55:45 +02:00
|
|
|
to the first (that is, the longest) matched string. Other parallel matches,
|
2017-05-30 12:42:57 +02:00
|
|
|
which are necessarily substrings of the first one, must obviously end before
|
2017-04-14 14:55:45 +02:00
|
|
|
the end of the subject.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_EXTENDED
|
|
|
|
.sp
|
|
|
|
If this bit is set, most white space characters in the pattern are totally
|
|
|
|
ignored except when escaped or inside a character class. However, white space
|
|
|
|
is not allowed within sequences such as (?> that introduce various
|
2019-02-06 19:11:36 +01:00
|
|
|
parenthesized groups, nor within numerical quantifiers such as {1,3}. Ignorable
|
|
|
|
white space is permitted between an item and a following quantifier and between
|
|
|
|
a quantifier and a following + that indicates possessiveness. PCRE2_EXTENDED is
|
|
|
|
equivalent to Perl's /x option, and it can be changed within a pattern by a
|
|
|
|
(?x) option setting.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2018-08-13 13:57:09 +02:00
|
|
|
When PCRE2 is compiled without Unicode support, PCRE2_EXTENDED recognizes as
|
|
|
|
white space only those characters with code points less than 256 that are
|
|
|
|
flagged as white space in its low-character table. The table is normally
|
|
|
|
created by
|
2018-08-03 11:38:36 +02:00
|
|
|
.\" HREF
|
2018-08-13 13:57:09 +02:00
|
|
|
\fBpcre2_maketables()\fP,
|
2018-08-03 11:38:36 +02:00
|
|
|
.\"
|
|
|
|
which uses the \fBisspace()\fP function to identify space characters. In most
|
|
|
|
ASCII environments, the relevant characters are those with code points 0x0009
|
|
|
|
(tab), 0x000A (linefeed), 0x000B (vertical tab), 0x000C (formfeed), 0x000D
|
2018-08-13 13:57:09 +02:00
|
|
|
(carriage return), and 0x0020 (space).
|
2018-08-03 11:38:36 +02:00
|
|
|
.P
|
|
|
|
When PCRE2 is compiled with Unicode support, in addition to these characters,
|
|
|
|
five more Unicode "Pattern White Space" characters are recognized by
|
|
|
|
PCRE2_EXTENDED. These are U+0085 (next line), U+200E (left-to-right mark),
|
|
|
|
U+200F (right-to-left mark), U+2028 (line separator), and U+2029 (paragraph
|
|
|
|
separator). This set of characters is the same as recognized by Perl's /x
|
|
|
|
option. Note that the horizontal and vertical space characters that are matched
|
|
|
|
by the \eh and \ev escapes in patterns are a much bigger set.
|
|
|
|
.P
|
|
|
|
As well as ignoring most white space, PCRE2_EXTENDED also causes characters
|
|
|
|
between an unescaped # outside a character class and the next newline,
|
|
|
|
inclusive, to be ignored, which makes it possible to include comments inside
|
|
|
|
complicated patterns. Note that the end of this type of comment is a literal
|
|
|
|
newline sequence in the pattern; escape sequences that happen to represent a
|
|
|
|
newline do not count.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
Which characters are interpreted as newlines can be specified by a setting in
|
|
|
|
the compile context that is passed to \fBpcre2_compile()\fP or by a special
|
|
|
|
sequence at the start of the pattern, as described in the section entitled
|
2014-11-14 19:41:20 +01:00
|
|
|
.\" HTML <a href="pcre2pattern.html#newlines">
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" </a>
|
|
|
|
"Newline conventions"
|
|
|
|
.\"
|
2014-10-20 19:28:49 +02:00
|
|
|
in the \fBpcre2pattern\fP documentation. A default is defined when PCRE2 is
|
2014-09-19 09:43:39 +02:00
|
|
|
built.
|
2017-04-18 14:32:52 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_EXTENDED_MORE
|
|
|
|
.sp
|
2017-04-20 18:34:35 +02:00
|
|
|
This option has the effect of PCRE2_EXTENDED, but, in addition, unescaped space
|
2018-08-13 13:57:09 +02:00
|
|
|
and horizontal tab characters are ignored inside a character class. Note: only
|
|
|
|
these two characters are ignored, not the full set of pattern white space
|
2018-08-03 11:38:36 +02:00
|
|
|
characters that are ignored outside a character class. PCRE2_EXTENDED_MORE is
|
|
|
|
equivalent to Perl's /xx option, and it can be changed within a pattern by a
|
|
|
|
(?xx) option setting.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_FIRSTLINE
|
|
|
|
.sp
|
2017-04-20 18:34:35 +02:00
|
|
|
If this option is set, the start of an unanchored pattern match must be before
|
2017-12-31 18:44:12 +01:00
|
|
|
or at the first newline in the subject string following the start of matching,
|
2018-01-13 17:53:02 +01:00
|
|
|
though the matched text may continue over the newline. If \fIstartoffset\fP is
|
|
|
|
non-zero, the limiting newline is not necessarily the first newline in the
|
2017-12-31 18:44:12 +01:00
|
|
|
subject. For example, if the subject string is "abc\enxyz" (where \en
|
|
|
|
represents a single-character newline) a pattern match for "yz" succeeds with
|
|
|
|
PCRE2_FIRSTLINE if \fIstartoffset\fP is greater than 3. See also
|
|
|
|
PCRE2_USE_OFFSET_LIMIT, which provides a more general limiting facility. If
|
|
|
|
PCRE2_FIRSTLINE is set with an offset limit, a match must occur in the first
|
|
|
|
line and also within the offset limit. In other words, whichever limit comes
|
|
|
|
first is used.
|
2017-06-15 18:41:44 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_LITERAL
|
|
|
|
.sp
|
2017-06-16 19:51:13 +02:00
|
|
|
If this option is set, all meta-characters in the pattern are disabled, and it
|
|
|
|
is treated as a literal string. Matching literal strings with a regular
|
|
|
|
expression engine is not the most efficient way of doing it. If you are doing a
|
|
|
|
lot of literal matching and are worried about efficiency, you should consider
|
|
|
|
using other approaches. The only other main options that are allowed with
|
|
|
|
PCRE2_LITERAL are: PCRE2_ANCHORED, PCRE2_ENDANCHORED, PCRE2_AUTO_CALLOUT,
|
2019-05-24 19:15:48 +02:00
|
|
|
PCRE2_CASELESS, PCRE2_FIRSTLINE, PCRE2_MATCH_INVALID_UTF,
|
|
|
|
PCRE2_NO_START_OPTIMIZE, PCRE2_NO_UTF_CHECK, PCRE2_UTF, and
|
|
|
|
PCRE2_USE_OFFSET_LIMIT. The extra options PCRE2_EXTRA_MATCH_LINE and
|
|
|
|
PCRE2_EXTRA_MATCH_WORD are also supported. Any other options cause an error.
|
|
|
|
.sp
|
|
|
|
PCRE2_MATCH_INVALID_UTF
|
|
|
|
.sp
|
|
|
|
This option forces PCRE2_UTF (see below) and also enables support for matching
|
|
|
|
by \fBpcre2_match()\fP in subject strings that contain invalid UTF sequences.
|
|
|
|
This facility is not supported for DFA matching. For details, see the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2unicode\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_MATCH_UNSET_BACKREF
|
|
|
|
.sp
|
2019-02-06 19:11:36 +01:00
|
|
|
If this option is set, a backreference to an unset capture group matches an
|
2014-09-19 09:43:39 +02:00
|
|
|
empty string (by default this causes the current matching alternative to fail).
|
|
|
|
A pattern such as (\e1)(a) succeeds when this option is set (assuming it can
|
|
|
|
find an "a" in the subject), whereas it fails by default, for Perl
|
2014-10-20 19:28:49 +02:00
|
|
|
compatibility. Setting this option makes PCRE2 behave more like ECMAscript (aka
|
2014-09-19 09:43:39 +02:00
|
|
|
JavaScript).
|
|
|
|
.sp
|
|
|
|
PCRE2_MULTILINE
|
|
|
|
.sp
|
|
|
|
By default, for the purposes of matching "start of line" and "end of line",
|
|
|
|
PCRE2 treats the subject string as consisting of a single line of characters,
|
|
|
|
even if it actually contains newlines. The "start of line" metacharacter (^)
|
|
|
|
matches only at the start of the string, and the "end of line" metacharacter
|
|
|
|
($) matches only at the end of the string, or before a terminating newline
|
|
|
|
(except when PCRE2_DOLLAR_ENDONLY is set). Note, however, that unless
|
|
|
|
PCRE2_DOTALL is set, the "any character" metacharacter (.) does not match at a
|
|
|
|
newline. This behaviour (for ^, $, and dot) is the same as Perl.
|
|
|
|
.P
|
|
|
|
When PCRE2_MULTILINE it is set, the "start of line" and "end of line"
|
|
|
|
constructs match immediately following or immediately before internal newlines
|
|
|
|
in the subject string, respectively, as well as at the very start and end. This
|
|
|
|
is equivalent to Perl's /m option, and it can be changed within a pattern by a
|
2015-04-22 19:39:25 +02:00
|
|
|
(?m) option setting. Note that the "start of line" metacharacter does not match
|
|
|
|
after a newline at the end of the subject, for compatibility with Perl.
|
|
|
|
However, you can change this by setting the PCRE2_ALT_CIRCUMFLEX option. If
|
|
|
|
there are no newlines in a subject string, or no occurrences of ^ or $ in a
|
|
|
|
pattern, setting PCRE2_MULTILINE has no effect.
|
2015-04-13 19:29:05 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_NEVER_BACKSLASH_C
|
|
|
|
.sp
|
2015-06-18 18:39:25 +02:00
|
|
|
This option locks out the use of \eC in the pattern that is being compiled.
|
2015-04-13 19:29:05 +02:00
|
|
|
This escape can cause unpredictable behaviour in UTF-8 or UTF-16 modes, because
|
|
|
|
it may leave the current matching point in the middle of a multi-code-unit
|
|
|
|
character. This option may be useful in applications that process patterns from
|
2015-12-17 19:44:06 +01:00
|
|
|
external sources. Note that there is also a build-time option that permanently
|
2015-10-17 15:50:56 +02:00
|
|
|
locks out the use of \eC.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_NEVER_UCP
|
|
|
|
.sp
|
|
|
|
This option locks out the use of Unicode properties for handling \eB, \eb, \eD,
|
2014-10-20 19:28:49 +02:00
|
|
|
\ed, \eS, \es, \eW, \ew, and some of the POSIX character classes, as described
|
|
|
|
for the PCRE2_UCP option below. In particular, it prevents the creator of the
|
|
|
|
pattern from enabling this facility by starting the pattern with (*UCP). This
|
2015-04-13 19:29:05 +02:00
|
|
|
option may be useful in applications that process patterns from external
|
|
|
|
sources. The option combination PCRE_UCP and PCRE_NEVER_UCP causes an error.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_NEVER_UTF
|
|
|
|
.sp
|
|
|
|
This option locks out interpretation of the pattern as UTF-8, UTF-16, or
|
|
|
|
UTF-32, depending on which library is in use. In particular, it prevents the
|
|
|
|
creator of the pattern from switching to UTF interpretation by starting the
|
2015-04-13 19:29:05 +02:00
|
|
|
pattern with (*UTF). This option may be useful in applications that process
|
|
|
|
patterns from external sources. The combination of PCRE2_UTF and
|
|
|
|
PCRE2_NEVER_UTF causes an error.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_NO_AUTO_CAPTURE
|
|
|
|
.sp
|
|
|
|
If this option is set, it disables the use of numbered capturing parentheses in
|
|
|
|
the pattern. Any opening parenthesis that is not followed by ? behaves as if it
|
|
|
|
were followed by ?: but named parentheses can still be used for capturing (and
|
2017-04-18 18:21:50 +02:00
|
|
|
they acquire numbers in the usual way). This is the same as Perl's /n option.
|
2019-02-06 19:11:36 +01:00
|
|
|
Note that, when this option is set, references to capture groups
|
2018-06-17 16:13:28 +02:00
|
|
|
(backreferences or recursion/subroutine calls) may only refer to named groups,
|
2016-01-31 20:14:15 +01:00
|
|
|
though the reference can be by name or by number.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_NO_AUTO_POSSESS
|
|
|
|
.sp
|
|
|
|
If this option is set, it disables "auto-possessification", which is an
|
|
|
|
optimization that, for example, turns a+b into a++b in order to avoid
|
|
|
|
backtracks into a+ that can never be successful. However, if callouts are in
|
|
|
|
use, auto-possessification means that some callouts are never taken. You can
|
|
|
|
set this option if you want the matching functions to do a full unoptimized
|
|
|
|
search and run all the callouts, but it is mainly provided for testing
|
|
|
|
purposes.
|
2015-01-02 18:09:16 +01:00
|
|
|
.sp
|
|
|
|
PCRE2_NO_DOTSTAR_ANCHOR
|
|
|
|
.sp
|
|
|
|
If this option is set, it disables an optimization that is applied when .* is
|
|
|
|
the first significant item in a top-level branch of a pattern, and all the
|
|
|
|
other branches also start with .* or with \eA or \eG or ^. The optimization is
|
2019-02-06 19:11:36 +01:00
|
|
|
automatically disabled for .* if it is inside an atomic group or a capture
|
2018-06-17 16:13:28 +02:00
|
|
|
group that is the subject of a backreference, or if the pattern contains
|
2015-01-02 18:09:16 +01:00
|
|
|
(*PRUNE) or (*SKIP). When the optimization is not disabled, such a pattern is
|
|
|
|
automatically anchored if PCRE2_DOTALL is set for all the .* items and
|
|
|
|
PCRE2_MULTILINE is not set for any ^ items. Otherwise, the fact that any match
|
|
|
|
must start either at the start of the subject or following a newline is
|
|
|
|
remembered. Like other optimizations, this can cause callouts to be skipped.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_NO_START_OPTIMIZE
|
|
|
|
.sp
|
2014-10-01 18:16:27 +02:00
|
|
|
This is an option whose main effect is at matching time. It does not change
|
|
|
|
what \fBpcre2_compile()\fP generates, but it does affect the output of the JIT
|
|
|
|
compiler.
|
|
|
|
.P
|
|
|
|
There are a number of optimizations that may occur at the start of a match, in
|
|
|
|
order to speed up the process. For example, if it is known that an unanchored
|
2017-04-20 18:34:35 +02:00
|
|
|
match must start with a specific code unit value, the matching code searches
|
|
|
|
the subject for that value, and fails immediately if it cannot find it, without
|
2014-10-01 18:16:27 +02:00
|
|
|
actually running the main matching function. This means that a special item
|
|
|
|
such as (*COMMIT) at the start of a pattern is not considered until after a
|
|
|
|
suitable starting point for the match has been found. Also, when callouts or
|
|
|
|
(*MARK) items are in use, these "start-up" optimizations can cause them to be
|
|
|
|
skipped if the pattern is never actually used. The start-up optimizations are
|
|
|
|
in effect a pre-scan of the subject that takes place before the pattern is run.
|
|
|
|
.P
|
|
|
|
The PCRE2_NO_START_OPTIMIZE option disables the start-up optimizations,
|
|
|
|
possibly causing performance to suffer, but ensuring that in cases where the
|
|
|
|
result is "no match", the callouts do occur, and that items such as (*COMMIT)
|
|
|
|
and (*MARK) are considered at every possible starting position in the subject
|
|
|
|
string.
|
|
|
|
.P
|
|
|
|
Setting PCRE2_NO_START_OPTIMIZE may change the outcome of a matching operation.
|
|
|
|
Consider the pattern
|
|
|
|
.sp
|
|
|
|
(*COMMIT)ABC
|
|
|
|
.sp
|
|
|
|
When this is compiled, PCRE2 records the fact that a match must start with the
|
|
|
|
character "A". Suppose the subject string is "DEFABC". The start-up
|
|
|
|
optimization scans along the subject, finds "A" and runs the first match
|
|
|
|
attempt from there. The (*COMMIT) item means that the pattern must match the
|
|
|
|
current starting position, which in this case, it does. However, if the same
|
|
|
|
match is run with PCRE2_NO_START_OPTIMIZE set, the initial scan along the
|
|
|
|
subject string does not happen. The first match attempt is run starting from
|
|
|
|
"D" and when this fails, (*COMMIT) prevents any further matches being tried, so
|
2017-05-30 12:42:57 +02:00
|
|
|
the overall result is "no match".
|
2017-04-20 18:34:35 +02:00
|
|
|
.P
|
2019-05-30 17:43:05 +02:00
|
|
|
As another start-up optimization makes use of a minimum length for a matching
|
|
|
|
subject, which is recorded when possible. Consider the pattern
|
2014-10-01 18:16:27 +02:00
|
|
|
.sp
|
2019-05-30 17:43:05 +02:00
|
|
|
(*MARK:1)B(*MARK:2)(X|Y)
|
2014-10-01 18:16:27 +02:00
|
|
|
.sp
|
2019-06-25 17:40:42 +02:00
|
|
|
The minimum length for a match is two characters. If the subject is "XXBB", the
|
|
|
|
"starting character" optimization skips "XX", then tries to match "BB", which
|
|
|
|
is long enough. In the process, (*MARK:2) is encountered and remembered. When
|
2019-05-30 17:43:05 +02:00
|
|
|
the match attempt fails, the next "B" is found, but there is only one character
|
|
|
|
left, so there are no more attempts, and "no match" is returned with the "last
|
|
|
|
mark seen" set to "2". If NO_START_OPTIMIZE is set, however, matches are tried
|
|
|
|
at every possible starting position, including at the end of the subject, where
|
|
|
|
(*MARK:1) is encountered, but there is no "B", so the "last mark seen" that is
|
|
|
|
returned is "1". In this case, the optimizations do not affect the overall
|
|
|
|
match result, which is still "no match", but they do affect the auxiliary
|
|
|
|
information that is returned.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_NO_UTF_CHECK
|
|
|
|
.sp
|
|
|
|
When PCRE2_UTF is set, the validity of the pattern as a UTF string is
|
|
|
|
automatically checked. There are discussions about the validity of
|
|
|
|
.\" HTML <a href="pcre2unicode.html#utf8strings">
|
|
|
|
.\" </a>
|
|
|
|
UTF-8 strings,
|
|
|
|
.\"
|
|
|
|
.\" HTML <a href="pcre2unicode.html#utf16strings">
|
|
|
|
.\" </a>
|
|
|
|
UTF-16 strings,
|
|
|
|
.\"
|
|
|
|
and
|
|
|
|
.\" HTML <a href="pcre2unicode.html#utf32strings">
|
|
|
|
.\" </a>
|
|
|
|
UTF-32 strings
|
|
|
|
.\"
|
|
|
|
in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2unicode\fP
|
|
|
|
.\"
|
2017-03-28 18:34:29 +02:00
|
|
|
document. If an invalid UTF sequence is found, \fBpcre2_compile()\fP returns a
|
2017-05-30 12:42:57 +02:00
|
|
|
negative error code.
|
2017-05-17 19:55:11 +02:00
|
|
|
.P
|
|
|
|
If you know that your pattern is a valid UTF string, and you want to skip this
|
|
|
|
check for performance reasons, you can set the PCRE2_NO_UTF_CHECK option. When
|
|
|
|
it is set, the effect of passing an invalid UTF string as a pattern is
|
2017-05-30 12:42:57 +02:00
|
|
|
undefined. It may cause your program to crash or loop.
|
2017-05-17 19:55:11 +02:00
|
|
|
.P
|
|
|
|
Note that this option can also be passed to \fBpcre2_match()\fP and
|
|
|
|
\fBpcre_dfa_match()\fP, to suppress UTF validity checking of the subject
|
|
|
|
string.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2017-05-17 19:55:11 +02:00
|
|
|
Note also that setting PCRE2_NO_UTF_CHECK at compile time does not disable the
|
|
|
|
error that is given if an escape sequence for an invalid Unicode code point is
|
|
|
|
encountered in the pattern. In particular, the so-called "surrogate" code
|
|
|
|
points (0xd800 to 0xdfff) are invalid. If you want to allow escape sequences
|
|
|
|
such as \ex{d800} you can set the PCRE2_EXTRA_ALLOW_SURROGATE_ESCAPES extra
|
|
|
|
option, as described in the section entitled "Extra compile options"
|
|
|
|
.\" HTML <a href="#extracompileoptions">
|
|
|
|
.\" </a>
|
2017-05-30 12:42:57 +02:00
|
|
|
below.
|
2017-05-17 19:55:11 +02:00
|
|
|
.\"
|
|
|
|
However, this is possible only in UTF-8 and UTF-32 modes, because these values
|
|
|
|
are not representable in UTF-16.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_UCP
|
|
|
|
.sp
|
2020-02-24 17:35:15 +01:00
|
|
|
This option has two effects. Firstly, it change the way PCRE2 processes \eB,
|
|
|
|
\eb, \eD, \ed, \eS, \es, \eW, \ew, and some of the POSIX character classes. By
|
|
|
|
default, only ASCII characters are recognized, but if PCRE2_UCP is set, Unicode
|
|
|
|
properties are used instead to classify characters. More details are given in
|
|
|
|
the section on
|
2014-11-14 19:41:20 +01:00
|
|
|
.\" HTML <a href="pcre2pattern.html#genericchartypes">
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" </a>
|
|
|
|
generic character types
|
|
|
|
.\"
|
|
|
|
in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2pattern\fP
|
|
|
|
.\"
|
|
|
|
page. If you set PCRE2_UCP, matching one of the items it affects takes much
|
2020-04-15 18:34:36 +02:00
|
|
|
longer.
|
2020-02-24 17:35:15 +01:00
|
|
|
.P
|
|
|
|
The second effect of PCRE2_UCP is to force the use of Unicode properties for
|
|
|
|
upper/lower casing operations on characters with code points greater than 127,
|
|
|
|
even when PCRE2_UTF is not set. This makes it possible, for example, to process
|
|
|
|
strings in the 16-bit UCS-2 code. This option is available only if PCRE2 has
|
|
|
|
been compiled with Unicode support (which is the default).
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_UNGREEDY
|
|
|
|
.sp
|
|
|
|
This option inverts the "greediness" of the quantifiers so that they are not
|
|
|
|
greedy by default, but become greedy if followed by "?". It is not compatible
|
|
|
|
with Perl. It can also be set by a (?U) option setting within the pattern.
|
2015-09-22 18:51:11 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_USE_OFFSET_LIMIT
|
|
|
|
.sp
|
2015-10-07 19:32:48 +02:00
|
|
|
This option must be set for \fBpcre2_compile()\fP if
|
|
|
|
\fBpcre2_set_offset_limit()\fP is going to be used to set a non-default offset
|
2015-09-22 18:51:11 +02:00
|
|
|
limit in a match context for matches that use this pattern. An error is
|
|
|
|
generated if an offset limit is set without this option. For more details, see
|
|
|
|
the description of \fBpcre2_set_offset_limit()\fP in the
|
|
|
|
.\" HTML <a href="#matchcontext">
|
|
|
|
.\" </a>
|
|
|
|
section
|
|
|
|
.\"
|
|
|
|
that describes match contexts. See also the PCRE2_FIRSTLINE
|
|
|
|
option above.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_UTF
|
|
|
|
.sp
|
|
|
|
This option causes PCRE2 to regard both the pattern and the subject strings
|
|
|
|
that are subsequently processed as strings of UTF characters instead of
|
2014-11-18 19:32:12 +01:00
|
|
|
single-code-unit strings. It is available when PCRE2 is built to include
|
|
|
|
Unicode support (which is the default). If Unicode support is not available,
|
2017-04-20 18:34:35 +02:00
|
|
|
the use of this option provokes an error. Details of how PCRE2_UTF changes the
|
|
|
|
behaviour of PCRE2 are given in the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2unicode\fP
|
|
|
|
.\"
|
2018-09-11 16:27:39 +02:00
|
|
|
page. In particular, note that it changes the way PCRE2_CASELESS handles
|
2018-09-02 18:03:27 +02:00
|
|
|
characters with code points greater than 127.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
2017-05-17 19:55:11 +02:00
|
|
|
.\" HTML <a name="extracompileoptions"></a>
|
|
|
|
.SS "Extra compile options"
|
|
|
|
.rs
|
|
|
|
.sp
|
2019-02-12 18:50:19 +01:00
|
|
|
The option bits that can be set in a compile context by calling the
|
|
|
|
\fBpcre2_set_compile_extra_options()\fP function are as follows:
|
2017-05-17 19:55:11 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_EXTRA_ALLOW_SURROGATE_ESCAPES
|
|
|
|
.sp
|
2017-05-30 12:42:57 +02:00
|
|
|
This option applies when compiling a pattern in UTF-8 or UTF-32 mode. It is
|
2017-05-17 19:55:11 +02:00
|
|
|
forbidden in UTF-16 mode, and ignored in non-UTF modes. Unicode "surrogate"
|
|
|
|
code points in the range 0xd800 to 0xdfff are used in pairs in UTF-16 to encode
|
2017-05-30 12:42:57 +02:00
|
|
|
code points with values in the range 0x10000 to 0x10ffff. The surrogates cannot
|
2017-05-17 19:55:11 +02:00
|
|
|
therefore be represented in UTF-16. They can be represented in UTF-8 and
|
2017-05-30 12:42:57 +02:00
|
|
|
UTF-32, but are defined as invalid code points, and cause errors if encountered
|
|
|
|
in a UTF-8 or UTF-32 string that is being checked for validity by PCRE2.
|
2017-05-17 19:55:11 +02:00
|
|
|
.P
|
|
|
|
These values also cause errors if encountered in escape sequences such as
|
|
|
|
\ex{d912} within a pattern. However, it seems that some applications, when
|
|
|
|
using PCRE2 to check for unwanted characters in UTF-8 strings, explicitly test
|
|
|
|
for the surrogates using escape sequences. The PCRE2_NO_UTF_CHECK option does
|
|
|
|
not disable the error that occurs, because it applies only to the testing of
|
|
|
|
input strings for UTF validity.
|
|
|
|
.P
|
2017-05-30 12:42:57 +02:00
|
|
|
If the extra option PCRE2_EXTRA_ALLOW_SURROGATE_ESCAPES is set, surrogate code
|
|
|
|
point values in UTF-8 and UTF-32 patterns no longer provoke errors and are
|
|
|
|
incorporated in the compiled pattern. However, they can only match subject
|
2017-05-17 19:55:11 +02:00
|
|
|
characters if the matching function is called with PCRE2_NO_UTF_CHECK set.
|
2019-02-12 18:50:19 +01:00
|
|
|
.sp
|
|
|
|
PCRE2_EXTRA_ALT_BSUX
|
|
|
|
.sp
|
2019-03-04 19:07:04 +01:00
|
|
|
The original option PCRE2_ALT_BSUX causes PCRE2 to process \eU, \eu, and \ex in
|
|
|
|
the way that ECMAscript (aka JavaScript) does. Additional functionality was
|
|
|
|
defined by ECMAscript 6; setting PCRE2_EXTRA_ALT_BSUX has the effect of
|
|
|
|
PCRE2_ALT_BSUX, but in addition it recognizes \eu{hhh..} as a hexadecimal
|
2019-02-12 18:50:19 +01:00
|
|
|
character code, where hhh.. is any number of hexadecimal digits.
|
2017-06-01 20:10:15 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_EXTRA_BAD_ESCAPE_IS_LITERAL
|
|
|
|
.sp
|
|
|
|
This is a dangerous option. Use with care. By default, an unrecognized escape
|
|
|
|
such as \ej or a malformed one such as \ex{2z} causes a compile-time error when
|
|
|
|
detected by \fBpcre2_compile()\fP. Perl is somewhat inconsistent in handling
|
|
|
|
such items: for example, \ej is treated as a literal "j", and non-hexadecimal
|
|
|
|
digits in \ex{} are just ignored, though warnings are given in both cases if
|
|
|
|
Perl's warning switch is enabled. However, a malformed octal number after \eo{
|
|
|
|
always causes an error in Perl.
|
|
|
|
.P
|
|
|
|
If the PCRE2_EXTRA_BAD_ESCAPE_IS_LITERAL extra option is passed to
|
2019-01-04 17:41:32 +01:00
|
|
|
\fBpcre2_compile()\fP, all unrecognized or malformed escape sequences are
|
2017-06-01 20:10:15 +02:00
|
|
|
treated as single-character escapes. For example, \ej is a literal "j" and
|
|
|
|
\ex{2z} is treated as the literal string "x{2z}". Setting this option means
|
2019-03-04 19:07:04 +01:00
|
|
|
that typos in patterns may go undetected and have unexpected results. Also note
|
2019-01-04 17:41:32 +01:00
|
|
|
that a sequence such as [\eN{] is interpreted as a malformed attempt at
|
|
|
|
[\eN{...}] and so is treated as [N{] whereas [\eN] gives an error because an
|
|
|
|
unqualified \eN is a valid escape sequence but is not supported in a character
|
|
|
|
class. To reiterate: this is a dangerous option. Use with great care.
|
2018-09-21 18:59:48 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_EXTRA_ESCAPED_CR_IS_LF
|
|
|
|
.sp
|
2019-03-04 19:07:04 +01:00
|
|
|
There are some legacy applications where the escape sequence \er in a pattern
|
|
|
|
is expected to match a newline. If this option is set, \er in a pattern is
|
|
|
|
converted to \en so that it matches a LF (linefeed) instead of a CR (carriage
|
2018-09-21 18:59:48 +02:00
|
|
|
return) character. The option does not affect a literal CR in the pattern, nor
|
|
|
|
does it affect CR specified as an explicit code point such as \ex{0D}.
|
2017-06-16 19:51:13 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_EXTRA_MATCH_LINE
|
|
|
|
.sp
|
|
|
|
This option is provided for use by the \fB-x\fP option of \fBpcre2grep\fP. It
|
2017-07-12 18:34:49 +02:00
|
|
|
causes the pattern only to match complete lines. This is achieved by
|
2017-06-16 19:51:13 +02:00
|
|
|
automatically inserting the code for "^(?:" at the start of the compiled
|
|
|
|
pattern and ")$" at the end. Thus, when PCRE2_MULTILINE is set, the matched
|
|
|
|
line may be in the middle of the subject string. This option can be used with
|
|
|
|
PCRE2_LITERAL.
|
|
|
|
.sp
|
|
|
|
PCRE2_EXTRA_MATCH_WORD
|
|
|
|
.sp
|
|
|
|
This option is provided for use by the \fB-w\fP option of \fBpcre2grep\fP. It
|
|
|
|
causes the pattern only to match strings that have a word boundary at the start
|
|
|
|
and the end. This is achieved by automatically inserting the code for "\eb(?:"
|
|
|
|
at the start of the compiled pattern and ")\eb" at the end. The option may be
|
|
|
|
used with PCRE2_LITERAL. However, it is ignored if PCRE2_EXTRA_MATCH_LINE is
|
|
|
|
also set.
|
2017-05-17 19:55:11 +02:00
|
|
|
.
|
|
|
|
.
|
2016-02-26 19:26:17 +01:00
|
|
|
.\" HTML <a name="jitcompiling"></a>
|
2014-09-19 09:43:39 +02:00
|
|
|
.SH "JUST-IN-TIME (JIT) COMPILATION"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_jit_compile(pcre2_code *\fIcode\fP, uint32_t \fIoptions\fP);
|
|
|
|
.sp
|
|
|
|
.B int pcre2_jit_match(const pcre2_code *\fIcode\fP, PCRE2_SPTR \fIsubject\fP,
|
|
|
|
.B " PCRE2_SIZE \fIlength\fP, PCRE2_SIZE \fIstartoffset\fP,"
|
|
|
|
.B " uint32_t \fIoptions\fP, pcre2_match_data *\fImatch_data\fP,"
|
2014-11-08 17:09:24 +01:00
|
|
|
.B " pcre2_match_context *\fImcontext\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
.B void pcre2_jit_free_unused_memory(pcre2_general_context *\fIgcontext\fP);
|
|
|
|
.sp
|
2014-11-28 13:46:16 +01:00
|
|
|
.B pcre2_jit_stack *pcre2_jit_stack_create(PCRE2_SIZE \fIstartsize\fP,
|
|
|
|
.B " PCRE2_SIZE \fImaxsize\fP, pcre2_general_context *\fIgcontext\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2014-11-08 17:09:24 +01:00
|
|
|
.B void pcre2_jit_stack_assign(pcre2_match_context *\fImcontext\fP,
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " pcre2_jit_callback \fIcallback_function\fP, void *\fIcallback_data\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_jit_stack_free(pcre2_jit_stack *\fIjit_stack\fP);
|
|
|
|
.fi
|
|
|
|
.P
|
|
|
|
These functions provide support for JIT compilation, which, if the just-in-time
|
|
|
|
compiler is available, further processes a compiled pattern into machine code
|
|
|
|
that executes much faster than the \fBpcre2_match()\fP interpretive matching
|
|
|
|
function. Full details are given in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2jit\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
|
|
|
.P
|
|
|
|
JIT compilation is a heavyweight optimization. It can take some time for
|
|
|
|
patterns to be analyzed, and for one-off matches and simple patterns the
|
|
|
|
benefit of faster execution might be offset by a much slower compilation time.
|
2017-03-28 18:34:29 +02:00
|
|
|
Most (but not all) patterns can be optimized by the JIT compiler.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.\" HTML <a name="localesupport"></a>
|
|
|
|
.SH "LOCALE SUPPORT"
|
|
|
|
.rs
|
|
|
|
.sp
|
2019-09-03 16:16:07 +02:00
|
|
|
.nf
|
|
|
|
.B const uint8_t *pcre2_maketables(pcre2_general_context *\fIgcontext\fP);
|
|
|
|
.sp
|
2019-10-17 18:39:38 +02:00
|
|
|
.B void pcre2_maketables_free(pcre2_general_context *\fIgcontext\fP,
|
2019-09-03 16:16:07 +02:00
|
|
|
.B " const uint8_t *\fItables\fP);"
|
|
|
|
.fi
|
|
|
|
.P
|
2014-09-19 09:43:39 +02:00
|
|
|
PCRE2 handles caseless matching, and determines whether characters are letters,
|
|
|
|
digits, or whatever, by reference to a set of tables, indexed by character code
|
2019-09-03 16:16:07 +02:00
|
|
|
point. However, this applies only to characters whose code points are less than
|
|
|
|
256. By default, higher-valued code points never match escapes such as \ew or
|
2020-04-15 18:34:36 +02:00
|
|
|
\ed.
|
2020-02-24 17:35:15 +01:00
|
|
|
.P
|
2020-04-15 18:34:36 +02:00
|
|
|
When PCRE2 is built with Unicode support (the default), the Unicode properties
|
2020-02-24 17:35:15 +01:00
|
|
|
of all characters can be tested with \ep and \eP, or, alternatively, the
|
|
|
|
PCRE2_UCP option can be set when a pattern is compiled; this causes \ew and
|
|
|
|
friends to use Unicode property support instead of the built-in tables.
|
|
|
|
PCRE2_UCP also causes upper/lower casing operations on characters with code
|
|
|
|
points greater than 127 to use Unicode properties. These effects apply even
|
|
|
|
when PCRE2_UTF is not set.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
The use of locales with Unicode is discouraged. If you are handling characters
|
2020-02-24 17:35:15 +01:00
|
|
|
with code points greater than 127, you should either use Unicode support, or
|
2014-09-19 09:43:39 +02:00
|
|
|
use locales, but not try to mix the two.
|
|
|
|
.P
|
2019-09-03 16:16:07 +02:00
|
|
|
PCRE2 contains a built-in set of character tables that are used by default.
|
2014-09-19 09:43:39 +02:00
|
|
|
These are sufficient for many applications. Normally, the internal tables
|
|
|
|
recognize only ASCII characters. However, when PCRE2 is built, it is possible
|
|
|
|
to cause the internal tables to be rebuilt in the default "C" locale of the
|
|
|
|
local system, which may cause them to be different.
|
|
|
|
.P
|
2019-09-03 16:16:07 +02:00
|
|
|
The built-in tables can be overridden by tables supplied by the application
|
2014-09-19 09:43:39 +02:00
|
|
|
that calls PCRE2. These may be created in a different locale from the default.
|
|
|
|
As more and more applications change to using Unicode, the need for this locale
|
|
|
|
support is expected to die away.
|
|
|
|
.P
|
|
|
|
External tables are built by calling the \fBpcre2_maketables()\fP function, in
|
2019-09-03 16:16:07 +02:00
|
|
|
the relevant locale. The only argument to this function is a general context,
|
|
|
|
which can be used to pass a custom memory allocator. If the argument is NULL,
|
|
|
|
the system \fBmalloc()\fP is used. The result can be passed to
|
|
|
|
\fBpcre2_compile()\fP as often as necessary, by creating a compile context and
|
|
|
|
calling \fBpcre2_set_character_tables()\fP to set the tables pointer therein.
|
|
|
|
.P
|
|
|
|
For example, to build and use tables that are appropriate for the French locale
|
2020-03-20 19:09:59 +01:00
|
|
|
(where accented characters with values greater than 127 are treated as
|
2014-09-19 09:43:39 +02:00
|
|
|
letters), the following code could be used:
|
|
|
|
.sp
|
|
|
|
setlocale(LC_CTYPE, "fr_FR");
|
|
|
|
tables = pcre2_maketables(NULL);
|
|
|
|
ccontext = pcre2_compile_context_create(NULL);
|
|
|
|
pcre2_set_character_tables(ccontext, tables);
|
|
|
|
re = pcre2_compile(..., ccontext);
|
|
|
|
.sp
|
|
|
|
The locale name "fr_FR" is used on Linux and other Unix-like systems; if you
|
2019-10-17 18:39:38 +02:00
|
|
|
are using Windows, the name for the French locale is "french".
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
The pointer that is passed (via the compile context) to \fBpcre2_compile()\fP
|
2020-03-20 19:09:59 +01:00
|
|
|
is saved with the compiled pattern, and the same tables are used by the
|
|
|
|
matching functions. Thus, for any single pattern, compilation and matching both
|
|
|
|
happen in the same locale, but different patterns can be processed in different
|
|
|
|
locales.
|
2019-09-03 16:16:07 +02:00
|
|
|
.P
|
|
|
|
It is the caller's responsibility to ensure that the memory containing the
|
|
|
|
tables remains available while they are still in use. When they are no longer
|
|
|
|
needed, you can discard them using \fBpcre2_maketables_free()\fP, which should
|
|
|
|
pass as its first parameter the same global context that was used to create the
|
|
|
|
tables.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
2020-03-20 19:09:59 +01:00
|
|
|
.SS "Saving locale tables"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
The tables described above are just a sequence of binary bytes, which makes
|
|
|
|
them independent of hardware characteristics such as endianness or whether the
|
|
|
|
processor is 32-bit or 64-bit. A copy of the result of \fBpcre2_maketables()\fP
|
|
|
|
can therefore be saved in a file or elsewhere and re-used later, even in a
|
|
|
|
different program or on another computer. The size of the tables (number of
|
|
|
|
bytes) must be obtained by calling \fBpcre2_config()\fP with the
|
|
|
|
PCRE2_CONFIG_TABLES_LENGTH option because \fBpcre2_maketables()\fP does not
|
|
|
|
return this value. Note that the \fBpcre2_dftables\fP program, which is part of
|
|
|
|
the PCRE2 build system, can be used stand-alone to create a file that contains
|
|
|
|
a set of binary tables. See the
|
|
|
|
.\" HTML <a href="pcre2build.html#createtables">
|
|
|
|
.\" </a>
|
|
|
|
\fBpcre2build\fP
|
|
|
|
.\"
|
|
|
|
documentation for details.
|
|
|
|
.
|
|
|
|
.
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HTML <a name="infoaboutpattern"></a>
|
|
|
|
.SH "INFORMATION ABOUT A COMPILED PATTERN"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_pattern_info(const pcre2 *\fIcode\fP, uint32_t \fIwhat\fP, void *\fIwhere\fP);
|
|
|
|
.fi
|
|
|
|
.P
|
2015-03-23 16:52:08 +01:00
|
|
|
The \fBpcre2_pattern_info()\fP function returns general information about a
|
|
|
|
compiled pattern. For information about callouts, see the
|
2020-03-20 19:09:59 +01:00
|
|
|
.\" HTML <a href="#infoaboutcallouts">
|
2015-03-23 16:52:08 +01:00
|
|
|
.\" </a>
|
|
|
|
next section.
|
|
|
|
.\"
|
|
|
|
The first argument for \fBpcre2_pattern_info()\fP is a pointer to the compiled
|
|
|
|
pattern. The second argument specifies which piece of information is required,
|
|
|
|
and the third argument is a pointer to a variable to receive the data. If the
|
|
|
|
third argument is NULL, the first argument is ignored, and the function returns
|
|
|
|
the size in bytes of the variable that is required for the information
|
2017-03-28 18:34:29 +02:00
|
|
|
requested. Otherwise, the yield of the function is zero for success, or one of
|
2015-03-23 16:52:08 +01:00
|
|
|
the following negative numbers:
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_NULL the argument \fIcode\fP was NULL
|
|
|
|
PCRE2_ERROR_BADMAGIC the "magic number" was not found
|
|
|
|
PCRE2_ERROR_BADOPTION the value of \fIwhat\fP was invalid
|
|
|
|
PCRE2_ERROR_UNSET the requested field is not set
|
|
|
|
.sp
|
2019-07-22 13:05:19 +02:00
|
|
|
The "magic number" is placed at the start of each compiled pattern as a simple
|
2014-10-16 18:49:23 +02:00
|
|
|
check against passing an arbitrary memory pointer. Here is a typical call of
|
|
|
|
\fBpcre2_pattern_info()\fP, to obtain the length of the compiled pattern:
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
int rc;
|
|
|
|
size_t length;
|
|
|
|
rc = pcre2_pattern_info(
|
|
|
|
re, /* result of pcre2_compile() */
|
|
|
|
PCRE2_INFO_SIZE, /* what is required */
|
|
|
|
&length); /* where to put the data */
|
|
|
|
.sp
|
|
|
|
The possible values for the second argument are defined in \fBpcre2.h\fP, and
|
|
|
|
are as follows:
|
|
|
|
.sp
|
|
|
|
PCRE2_INFO_ALLOPTIONS
|
2014-10-20 19:28:49 +02:00
|
|
|
PCRE2_INFO_ARGOPTIONS
|
2018-01-13 17:53:02 +01:00
|
|
|
PCRE2_INFO_EXTRAOPTIONS
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2017-12-16 18:49:26 +01:00
|
|
|
Return copies of the pattern's options. The third argument should point to a
|
2014-09-19 09:43:39 +02:00
|
|
|
\fBuint32_t\fP variable. PCRE2_INFO_ARGOPTIONS returns exactly the options that
|
|
|
|
were passed to \fBpcre2_compile()\fP, whereas PCRE2_INFO_ALLOPTIONS returns
|
2016-02-27 13:10:40 +01:00
|
|
|
the compile options as modified by any top-level (*XXX) option settings such as
|
2018-01-13 17:53:02 +01:00
|
|
|
(*UTF) at the start of the pattern itself. PCRE2_INFO_EXTRAOPTIONS returns the
|
2017-12-16 18:49:26 +01:00
|
|
|
extra options that were set in the compile context by calling the
|
|
|
|
pcre2_set_compile_extra_options() function.
|
2016-02-27 13:10:40 +01:00
|
|
|
.P
|
|
|
|
For example, if the pattern /(*UTF)abc/ is compiled with the PCRE2_EXTENDED
|
|
|
|
option, the result for PCRE2_INFO_ALLOPTIONS is PCRE2_EXTENDED and PCRE2_UTF.
|
|
|
|
Option settings such as (?i) that can change within a pattern do not affect the
|
|
|
|
result of PCRE2_INFO_ALLOPTIONS, even if they appear right at the start of the
|
|
|
|
pattern. (This was different in some earlier releases.)
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2015-01-02 18:09:16 +01:00
|
|
|
A pattern compiled without PCRE2_ANCHORED is automatically anchored by PCRE2 if
|
|
|
|
the first significant item in every top-level branch is one of the following:
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
^ unless PCRE2_MULTILINE is set
|
|
|
|
\eA always
|
|
|
|
\eG always
|
2015-01-02 18:09:16 +01:00
|
|
|
.* sometimes - see below
|
|
|
|
.sp
|
|
|
|
When .* is the first significant item, anchoring is possible only when all the
|
|
|
|
following are true:
|
|
|
|
.sp
|
|
|
|
.* is not in an atomic group
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" JOIN
|
2019-02-06 19:11:36 +01:00
|
|
|
.* is not in a capture group that is the subject
|
2018-06-17 16:13:28 +02:00
|
|
|
of a backreference
|
2015-01-02 18:09:16 +01:00
|
|
|
PCRE2_DOTALL is in force for .*
|
2017-03-28 18:34:29 +02:00
|
|
|
Neither (*PRUNE) nor (*SKIP) appears in the pattern
|
|
|
|
PCRE2_NO_DOTSTAR_ANCHOR is not set
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
2015-01-02 18:09:16 +01:00
|
|
|
For patterns that are auto-anchored, the PCRE2_ANCHORED bit is set in the
|
|
|
|
options returned for PCRE2_INFO_ALLOPTIONS.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_BACKREFMAX
|
|
|
|
.sp
|
2018-06-17 16:13:28 +02:00
|
|
|
Return the number of the highest backreference in the pattern. The third
|
2019-07-22 13:05:19 +02:00
|
|
|
argument should point to a \fBuint32_t\fP variable. Named capture groups
|
2019-02-06 19:11:36 +01:00
|
|
|
acquire numbers as well as names, and these count towards the highest
|
|
|
|
backreference. Backreferences such as \e4 or \eg{12} match the captured
|
|
|
|
characters of the given group, but in addition, the check that a capture
|
|
|
|
group is set in a conditional group such as (?(3)a|b) is also a backreference.
|
|
|
|
Zero is returned if there are no backreferences.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_BSR
|
|
|
|
.sp
|
2018-06-17 16:13:28 +02:00
|
|
|
The output is a uint32_t integer whose value indicates what character sequences
|
|
|
|
the \eR escape sequence matches. A value of PCRE2_BSR_UNICODE means that \eR
|
|
|
|
matches any Unicode line ending sequence; a value of PCRE2_BSR_ANYCRLF means
|
|
|
|
that \eR matches only CR, LF, or CRLF.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_CAPTURECOUNT
|
|
|
|
.sp
|
2019-02-06 19:11:36 +01:00
|
|
|
Return the highest capture group number in the pattern. In patterns where (?|
|
|
|
|
is not used, this is also the total number of capture groups. The third
|
2019-07-22 13:05:19 +02:00
|
|
|
argument should point to a \fBuint32_t\fP variable.
|
2017-03-28 18:34:29 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_DEPTHLIMIT
|
|
|
|
.sp
|
|
|
|
If the pattern set a backtracking depth limit by including an item of the form
|
|
|
|
(*LIMIT_DEPTH=nnnn) at the start, the value is returned. The third argument
|
2018-06-17 16:13:28 +02:00
|
|
|
should point to a uint32_t integer. If no such value has been set, the call to
|
|
|
|
\fBpcre2_pattern_info()\fP returns the error PCRE2_ERROR_UNSET. Note that this
|
|
|
|
limit will only be used during matching if it is less than the limit set or
|
|
|
|
defaulted by the caller of the match function.
|
2015-11-21 17:27:06 +01:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_FIRSTBITMAP
|
|
|
|
.sp
|
|
|
|
In the absence of a single first code unit for a non-anchored pattern,
|
|
|
|
\fBpcre2_compile()\fP may construct a 256-bit table that defines a fixed set of
|
|
|
|
values for the first code unit in any match. For example, a pattern that starts
|
|
|
|
with [abc] results in a table with three bits set. When code unit values
|
|
|
|
greater than 255 are supported, the flag bit for 255 means "any code unit of
|
|
|
|
value 255 or above". If such a table was constructed, a pointer to it is
|
2018-06-17 16:13:28 +02:00
|
|
|
returned. Otherwise NULL is returned. The third argument should point to a
|
2015-11-21 17:27:06 +01:00
|
|
|
\fBconst uint8_t *\fP variable.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_FIRSTCODETYPE
|
|
|
|
.sp
|
|
|
|
Return information about the first code unit of any matched string, for a
|
2019-07-22 13:05:19 +02:00
|
|
|
non-anchored pattern. The third argument should point to a \fBuint32_t\fP
|
2015-12-17 19:44:06 +01:00
|
|
|
variable. If there is a fixed first value, for example, the letter "c" from a
|
2017-04-20 18:34:35 +02:00
|
|
|
pattern such as (cat|cow|coyote), 1 is returned, and the value can be retrieved
|
|
|
|
using PCRE2_INFO_FIRSTCODEUNIT. If there is no fixed first value, but it is
|
|
|
|
known that a match can occur only at the start of the subject or following a
|
|
|
|
newline in the subject, 2 is returned. Otherwise, and for anchored patterns, 0
|
|
|
|
is returned.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_FIRSTCODEUNIT
|
|
|
|
.sp
|
2017-04-20 18:34:35 +02:00
|
|
|
Return the value of the first code unit of any matched string for a pattern
|
2014-09-19 09:43:39 +02:00
|
|
|
where PCRE2_INFO_FIRSTCODETYPE returns 1; otherwise return 0. The third
|
2019-07-22 13:05:19 +02:00
|
|
|
argument should point to a \fBuint32_t\fP variable. In the 8-bit library, the
|
2014-09-19 09:43:39 +02:00
|
|
|
value is always less than 256. In the 16-bit library the value can be up to
|
|
|
|
0xffff. In the 32-bit library in UTF-32 mode the value can be up to 0x10ffff,
|
|
|
|
and up to 0xffffffff when not using UTF-32 mode.
|
2017-03-28 18:34:29 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_FRAMESIZE
|
|
|
|
.sp
|
|
|
|
Return the size (in bytes) of the data frames that are used to remember
|
|
|
|
backtracking positions when the pattern is processed by \fBpcre2_match()\fP
|
2018-06-17 16:13:28 +02:00
|
|
|
without the use of JIT. The third argument should point to a \fBsize_t\fP
|
2017-03-28 18:34:29 +02:00
|
|
|
variable. The frame size depends on the number of capturing parentheses in the
|
2019-02-06 19:11:36 +01:00
|
|
|
pattern. Each additional capture group adds two PCRE2_SIZE variables.
|
2015-11-14 18:28:19 +01:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_HASBACKSLASHC
|
|
|
|
.sp
|
|
|
|
Return 1 if the pattern contains any instances of \eC, otherwise 0. The third
|
2019-07-22 13:05:19 +02:00
|
|
|
argument should point to a \fBuint32_t\fP variable.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_HASCRORLF
|
|
|
|
.sp
|
|
|
|
Return 1 if the pattern contains any explicit matches for CR or LF characters,
|
2019-07-22 13:05:19 +02:00
|
|
|
otherwise 0. The third argument should point to a \fBuint32_t\fP variable. An
|
2017-03-28 18:34:29 +02:00
|
|
|
explicit match is either a literal CR or LF character, or \er or \en or one of
|
|
|
|
the equivalent hexadecimal or octal escape sequences.
|
2017-04-11 13:47:25 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_HEAPLIMIT
|
|
|
|
.sp
|
|
|
|
If the pattern set a heap memory limit by including an item of the form
|
|
|
|
(*LIMIT_HEAP=nnnn) at the start, the value is returned. The third argument
|
2018-06-17 16:13:28 +02:00
|
|
|
should point to a uint32_t integer. If no such value has been set, the call to
|
|
|
|
\fBpcre2_pattern_info()\fP returns the error PCRE2_ERROR_UNSET. Note that this
|
|
|
|
limit will only be used during matching if it is less than the limit set or
|
|
|
|
defaulted by the caller of the match function.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_JCHANGED
|
|
|
|
.sp
|
|
|
|
Return 1 if the (?J) or (?-J) option setting is used in the pattern, otherwise
|
2019-07-22 13:05:19 +02:00
|
|
|
0. The third argument should point to a \fBuint32_t\fP variable. (?J) and
|
2014-09-19 09:43:39 +02:00
|
|
|
(?-J) set and unset the local PCRE2_DUPNAMES option, respectively.
|
|
|
|
.sp
|
|
|
|
PCRE2_INFO_JITSIZE
|
|
|
|
.sp
|
|
|
|
If the compiled pattern was successfully processed by
|
|
|
|
\fBpcre2_jit_compile()\fP, return the size of the JIT compiled code, otherwise
|
|
|
|
return zero. The third argument should point to a \fBsize_t\fP variable.
|
|
|
|
.sp
|
|
|
|
PCRE2_INFO_LASTCODETYPE
|
|
|
|
.sp
|
|
|
|
Returns 1 if there is a rightmost literal code unit that must exist in any
|
2019-07-22 13:05:19 +02:00
|
|
|
matched string, other than at its start. The third argument should point to a
|
2014-10-20 19:28:49 +02:00
|
|
|
\fBuint32_t\fP variable. If there is no such value, 0 is returned. When 1 is
|
2014-09-19 09:43:39 +02:00
|
|
|
returned, the code unit value itself can be retrieved using
|
2015-12-17 19:44:06 +01:00
|
|
|
PCRE2_INFO_LASTCODEUNIT. For anchored patterns, a last literal value is
|
|
|
|
recorded only if it follows something of variable length. For example, for the
|
|
|
|
pattern /^a\ed+z\ed+/ the returned value is 1 (with "z" returned from
|
|
|
|
PCRE2_INFO_LASTCODEUNIT), but for /^a\edz\ed/ the returned value is 0.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_LASTCODEUNIT
|
|
|
|
.sp
|
2017-04-20 18:34:35 +02:00
|
|
|
Return the value of the rightmost literal code unit that must exist in any
|
|
|
|
matched string, other than at its start, for a pattern where
|
|
|
|
PCRE2_INFO_LASTCODETYPE returns 1. Otherwise, return 0. The third argument
|
2019-07-22 13:05:19 +02:00
|
|
|
should point to a \fBuint32_t\fP variable.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_MATCHEMPTY
|
|
|
|
.sp
|
2015-11-11 10:42:26 +01:00
|
|
|
Return 1 if the pattern might match an empty string, otherwise 0. The third
|
2019-07-22 13:05:19 +02:00
|
|
|
argument should point to a \fBuint32_t\fP variable. When a pattern contains
|
2015-12-17 19:44:06 +01:00
|
|
|
recursive subroutine calls it is not always possible to determine whether or
|
|
|
|
not it can match an empty string. PCRE2 takes a cautious approach and returns 1
|
2015-11-11 10:42:26 +01:00
|
|
|
in such cases.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_MATCHLIMIT
|
|
|
|
.sp
|
|
|
|
If the pattern set a match limit by including an item of the form
|
|
|
|
(*LIMIT_MATCH=nnnn) at the start, the value is returned. The third argument
|
2018-06-17 16:13:28 +02:00
|
|
|
should point to a uint32_t integer. If no such value has been set, the call to
|
|
|
|
\fBpcre2_pattern_info()\fP returns the error PCRE2_ERROR_UNSET. Note that this
|
|
|
|
limit will only be used during matching if it is less than the limit set or
|
|
|
|
defaulted by the caller of the match function.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_MAXLOOKBEHIND
|
|
|
|
.sp
|
2019-09-04 20:14:54 +02:00
|
|
|
A lookbehind assertion moves back a certain number of characters (not code
|
|
|
|
units) when it starts to process each of its branches. This request returns the
|
|
|
|
largest of these backward moves. The third argument should point to a uint32_t
|
|
|
|
integer. The simple assertions \eb and \eB require a one-character lookbehind
|
|
|
|
and cause PCRE2_INFO_MAXLOOKBEHIND to return 1 in the absence of anything
|
|
|
|
longer. \eA also registers a one-character lookbehind, though it does not
|
|
|
|
actually inspect the previous character.
|
|
|
|
.P
|
|
|
|
Note that this information is useful for multi-segment matching only
|
2019-10-17 18:39:38 +02:00
|
|
|
if the pattern contains no nested lookbehinds. For example, the pattern
|
|
|
|
(?<=a(?<=ba)c) returns a maximum lookbehind of 2, but when it is processed, the
|
2019-09-04 20:14:54 +02:00
|
|
|
first lookbehind moves back by two characters, matches one character, then the
|
|
|
|
nested lookbehind also moves back by two characters. This puts the matching
|
|
|
|
point three characters earlier than it was at the start.
|
|
|
|
PCRE2_INFO_MAXLOOKBEHIND is really only useful as a debugging tool. See the
|
2019-06-25 17:40:42 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2partial\fP
|
|
|
|
.\"
|
2019-09-04 20:14:54 +02:00
|
|
|
documentation for a discussion of multi-segment matching.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_MINLENGTH
|
|
|
|
.sp
|
|
|
|
If a minimum length for matching subject strings was computed, its value is
|
2019-06-13 18:00:11 +02:00
|
|
|
returned. Otherwise the returned value is 0. This value is not computed when
|
|
|
|
PCRE2_NO_START_OPTIMIZE is set. The value is a number of characters, which in
|
|
|
|
UTF mode may be different from the number of code units. The third argument
|
2019-07-22 13:05:19 +02:00
|
|
|
should point to a \fBuint32_t\fP variable. The value is a lower bound to the
|
2019-06-13 18:00:11 +02:00
|
|
|
length of any matching string. There may not be any strings of that length that
|
|
|
|
do actually match, but every string that does match is at least that long.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_NAMECOUNT
|
|
|
|
PCRE2_INFO_NAMEENTRYSIZE
|
|
|
|
PCRE2_INFO_NAMETABLE
|
|
|
|
.sp
|
|
|
|
PCRE2 supports the use of named as well as numbered capturing parentheses. The
|
|
|
|
names are just an additional way of identifying the parentheses, which still
|
|
|
|
acquire numbers. Several convenience functions such as
|
|
|
|
\fBpcre2_substring_get_byname()\fP are provided for extracting captured
|
|
|
|
substrings by name. It is also possible to extract the data directly, by first
|
|
|
|
converting the name to a number in order to access the correct pointers in the
|
|
|
|
output vector (described with \fBpcre2_match()\fP below). To do the conversion,
|
|
|
|
you need to use the name-to-number map, which is described by these three
|
|
|
|
values.
|
|
|
|
.P
|
|
|
|
The map consists of a number of fixed-size entries. PCRE2_INFO_NAMECOUNT gives
|
|
|
|
the number of entries, and PCRE2_INFO_NAMEENTRYSIZE gives the size of each
|
2014-11-21 17:45:06 +01:00
|
|
|
entry in code units; both of these return a \fBuint32_t\fP value. The entry
|
|
|
|
size depends on the length of the longest name.
|
|
|
|
.P
|
|
|
|
PCRE2_INFO_NAMETABLE returns a pointer to the first entry of the table. This is
|
|
|
|
a PCRE2_SPTR pointer to a block of code units. In the 8-bit library, the first
|
|
|
|
two bytes of each entry are the number of the capturing parenthesis, most
|
|
|
|
significant byte first. In the 16-bit library, the pointer points to 16-bit
|
|
|
|
code units, the first of which contains the parenthesis number. In the 32-bit
|
|
|
|
library, the pointer points to 32-bit code units, the first of which contains
|
|
|
|
the parenthesis number. The rest of the entry is the corresponding name, zero
|
|
|
|
terminated.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2019-02-06 19:11:36 +01:00
|
|
|
The names are in alphabetical order. If (?| is used to create multiple capture
|
|
|
|
groups with the same number, as described in the
|
|
|
|
.\" HTML <a href="pcre2pattern.html#dupgroupnumber">
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" </a>
|
2019-02-06 19:11:36 +01:00
|
|
|
section on duplicate group numbers
|
2014-09-19 09:43:39 +02:00
|
|
|
.\"
|
|
|
|
in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2pattern\fP
|
|
|
|
.\"
|
|
|
|
page, the groups may be given the same name, but there is only one entry in the
|
|
|
|
table. Different names for groups of the same number are not permitted.
|
|
|
|
.P
|
2019-02-06 19:11:36 +01:00
|
|
|
Duplicate names for capture groups with different numbers are permitted, but
|
|
|
|
only if PCRE2_DUPNAMES is set. They appear in the table in the order in which
|
|
|
|
they were found in the pattern. In the absence of (?| this is the order of
|
2014-09-19 09:43:39 +02:00
|
|
|
increasing number; when (?| is used this is not necessarily the case because
|
2019-02-06 19:11:36 +01:00
|
|
|
later capture groups may have lower numbers.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
As a simple example of the name/number table, consider the following pattern
|
|
|
|
after compilation by the 8-bit library (assume PCRE2_EXTENDED is set, so white
|
|
|
|
space - including newlines - is ignored):
|
|
|
|
.sp
|
|
|
|
.\" JOIN
|
|
|
|
(?<date> (?<year>(\ed\ed)?\ed\ed) -
|
|
|
|
(?<month>\ed\ed) - (?<day>\ed\ed) )
|
|
|
|
.sp
|
2019-02-06 19:11:36 +01:00
|
|
|
There are four named capture groups, so the table has four entries, and each
|
|
|
|
entry in the table is eight bytes long. The table is as follows, with
|
|
|
|
non-printing bytes shows in hexadecimal, and undefined bytes shown as ??:
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
00 01 d a t e 00 ??
|
|
|
|
00 05 d a y 00 ?? ??
|
|
|
|
00 04 m o n t h 00
|
|
|
|
00 02 y e a r 00 ??
|
|
|
|
.sp
|
2019-02-06 19:11:36 +01:00
|
|
|
When writing code to extract data from named capture groups using the
|
2014-09-19 09:43:39 +02:00
|
|
|
name-to-number map, remember that the length of the entries is likely to be
|
|
|
|
different for each compiled pattern.
|
|
|
|
.sp
|
|
|
|
PCRE2_INFO_NEWLINE
|
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
The output is one of the following \fBuint32_t\fP values:
|
2014-10-20 19:28:49 +02:00
|
|
|
.sp
|
2014-11-18 19:32:12 +01:00
|
|
|
PCRE2_NEWLINE_CR Carriage return (CR)
|
|
|
|
PCRE2_NEWLINE_LF Linefeed (LF)
|
|
|
|
PCRE2_NEWLINE_CRLF Carriage return, linefeed (CRLF)
|
|
|
|
PCRE2_NEWLINE_ANY Any Unicode line ending
|
|
|
|
PCRE2_NEWLINE_ANYCRLF Any of CR, LF, or CRLF
|
2017-05-30 12:42:57 +02:00
|
|
|
PCRE2_NEWLINE_NUL The NUL character (binary zero)
|
2014-11-21 17:45:06 +01:00
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
This identifies the character sequence that will be recognized as meaning
|
|
|
|
"newline" while matching.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_INFO_SIZE
|
|
|
|
.sp
|
|
|
|
Return the size of the compiled pattern in bytes (for all three libraries). The
|
2015-01-23 17:51:47 +01:00
|
|
|
third argument should point to a \fBsize_t\fP variable. This value includes the
|
|
|
|
size of the general data block that precedes the code units of the compiled
|
|
|
|
pattern itself. The value that is used when \fBpcre2_compile()\fP is getting
|
|
|
|
memory in which to place the compiled pattern may be slightly larger than the
|
|
|
|
value returned by this option, because there are cases where the code that
|
|
|
|
calculates the size has to over-estimate. Processing a pattern with the JIT
|
|
|
|
compiler does not alter the value returned by this option.
|
|
|
|
.
|
|
|
|
.
|
2015-03-23 16:52:08 +01:00
|
|
|
.\" HTML <a name="infoaboutcallouts"></a>
|
|
|
|
.SH "INFORMATION ABOUT A PATTERN'S CALLOUTS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_callout_enumerate(const pcre2_code *\fIcode\fP,
|
|
|
|
.B " int (*\fIcallback\fP)(pcre2_callout_enumerate_block *, void *),"
|
|
|
|
.B " void *\fIuser_data\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
2015-06-18 18:39:25 +02:00
|
|
|
A script language that supports the use of string arguments in callouts might
|
|
|
|
like to scan all the callouts in a pattern before running the match. This can
|
|
|
|
be done by calling \fBpcre2_callout_enumerate()\fP. The first argument is a
|
2015-03-23 16:52:08 +01:00
|
|
|
pointer to a compiled pattern, the second points to a callback function, and
|
|
|
|
the third is arbitrary user data. The callback function is called for every
|
|
|
|
callout in the pattern in the order in which they appear. Its first argument is
|
|
|
|
a pointer to a callout enumeration block, and its second argument is the
|
2015-06-18 18:39:25 +02:00
|
|
|
\fIuser_data\fP value that was passed to \fBpcre2_callout_enumerate()\fP. The
|
2015-03-23 16:52:08 +01:00
|
|
|
contents of the callout enumeration block are described in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2callout\fP
|
|
|
|
.\"
|
|
|
|
documentation, which also gives further details about callouts.
|
|
|
|
.
|
|
|
|
.
|
2015-01-23 17:51:47 +01:00
|
|
|
.SH "SERIALIZATION AND PRECOMPILING"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
It is possible to save compiled patterns on disc or elsewhere, and reload them
|
2018-06-27 19:20:58 +02:00
|
|
|
later, subject to a number of restrictions. The host on which the patterns are
|
|
|
|
reloaded must be running the same version of PCRE2, with the same code unit
|
|
|
|
width, and must also have the same endianness, pointer width, and PCRE2_SIZE
|
|
|
|
type. Before compiled patterns can be saved, they must be converted to a
|
|
|
|
"serialized" form, which in the case of PCRE2 is really just a bytecode dump.
|
2018-08-13 13:57:09 +02:00
|
|
|
The functions whose names begin with \fBpcre2_serialize_\fP are used for
|
2018-06-27 19:20:58 +02:00
|
|
|
converting to and from the serialized form. They are described in the
|
2015-01-23 17:51:47 +01:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2serialize\fP
|
|
|
|
.\"
|
2018-06-27 19:20:58 +02:00
|
|
|
documentation. Note that PCRE2 serialization does not convert compiled patterns
|
|
|
|
to an abstract format like Java or .NET serialization.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.\" HTML <a name="matchdatablock"></a>
|
|
|
|
.SH "THE MATCH DATA BLOCK"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
2015-07-29 10:03:34 +02:00
|
|
|
.B pcre2_match_data *pcre2_match_data_create(uint32_t \fIovecsize\fP,
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " pcre2_general_context *\fIgcontext\fP);"
|
|
|
|
.sp
|
2015-07-29 10:03:34 +02:00
|
|
|
.B pcre2_match_data *pcre2_match_data_create_from_pattern(
|
|
|
|
.B " const pcre2_code *\fIcode\fP, pcre2_general_context *\fIgcontext\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
.B void pcre2_match_data_free(pcre2_match_data *\fImatch_data\fP);
|
|
|
|
.fi
|
|
|
|
.P
|
2014-12-14 18:17:06 +01:00
|
|
|
Information about a successful or unsuccessful match is placed in a match
|
2014-09-19 09:43:39 +02:00
|
|
|
data block, which is an opaque structure that is accessed by function calls. In
|
|
|
|
particular, the match data block contains a vector of offsets into the subject
|
2021-08-28 17:25:59 +02:00
|
|
|
string that define the matched parts of the subject. This is known as the
|
|
|
|
\fIovector\fP.
|
2014-11-18 19:32:12 +01:00
|
|
|
.P
|
2014-11-21 17:45:06 +01:00
|
|
|
Before calling \fBpcre2_match()\fP, \fBpcre2_dfa_match()\fP, or
|
2014-11-18 19:32:12 +01:00
|
|
|
\fBpcre2_jit_match()\fP you must create a match data block by calling one of
|
|
|
|
the creation functions above. For \fBpcre2_match_data_create()\fP, the first
|
2021-08-28 17:25:59 +02:00
|
|
|
argument is the number of pairs of offsets in the \fIovector\fP.
|
|
|
|
.P
|
|
|
|
When using \fBpcre2_match()\fP, one pair of offsets is required to identify the
|
|
|
|
string that matched the whole pattern, with an additional pair for each
|
|
|
|
captured substring. For example, a value of 4 creates enough space to record
|
|
|
|
the matched portion of the subject plus three captured substrings.
|
|
|
|
.P
|
|
|
|
When using \fBpcre2_dfa_match()\fP there may be multiple matched substrings of
|
|
|
|
different lengths at the same point in the subject. The ovector should be made
|
|
|
|
large enough to hold as many as are expected.
|
|
|
|
.P
|
|
|
|
A minimum of at least 1 pair is imposed by \fBpcre2_match_data_create()\fP, so
|
|
|
|
it is always possible to return the overall matched string in the case of
|
|
|
|
\fBpcre2_match()\fP or the longest match in the case of
|
|
|
|
\fBpcre2_dfa_match()\fP.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2014-11-28 14:23:40 +01:00
|
|
|
The second argument of \fBpcre2_match_data_create()\fP is a pointer to a
|
|
|
|
general context, which can specify custom memory management for obtaining the
|
|
|
|
memory for the match data block. If you are not using custom memory management,
|
|
|
|
pass NULL, which causes \fBmalloc()\fP to be used.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2014-11-28 14:23:40 +01:00
|
|
|
For \fBpcre2_match_data_create_from_pattern()\fP, the first argument is a
|
|
|
|
pointer to a compiled pattern. The ovector is created to be exactly the right
|
2021-08-28 17:25:59 +02:00
|
|
|
size to hold all the substrings a pattern might capture when matched using
|
|
|
|
\fBpcre2_match()\fP. You should not use this call when matching with
|
|
|
|
\fBpcre2_dfa_match()\fP. The second argument is again a pointer to a general
|
|
|
|
context, but in this case if NULL is passed, the memory is obtained using the
|
|
|
|
same allocator that was used for the compiled pattern (custom or default).
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
A match data block can be used many times, with the same or different compiled
|
2014-12-14 18:17:06 +01:00
|
|
|
patterns. You can extract information from a match data block after a match
|
|
|
|
operation has finished, using functions that are described in the sections on
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HTML <a href="#matchedstrings">
|
|
|
|
.\" </a>
|
|
|
|
matched strings
|
|
|
|
.\"
|
|
|
|
and
|
|
|
|
.\" HTML <a href="#matchotherdata">
|
|
|
|
.\" </a>
|
|
|
|
other match data
|
|
|
|
.\"
|
|
|
|
below.
|
2014-12-14 18:17:06 +01:00
|
|
|
.P
|
2014-12-22 18:33:10 +01:00
|
|
|
When a call of \fBpcre2_match()\fP fails, valid data is available in the match
|
|
|
|
block only when the error is PCRE2_ERROR_NOMATCH, PCRE2_ERROR_PARTIAL, or one
|
|
|
|
of the error codes for an invalid UTF string. Exactly what is available depends
|
|
|
|
on the error, and is detailed below.
|
|
|
|
.P
|
2014-12-14 18:17:06 +01:00
|
|
|
When one of the matching functions is called, pointers to the compiled pattern
|
|
|
|
and the subject string are set in the match data block so that they can be
|
2018-10-19 17:31:16 +02:00
|
|
|
referenced by the extraction functions after a successful match. After running
|
|
|
|
a match, you must not free a compiled pattern or a subject string until after
|
|
|
|
all operations on the match data block (for that match) have taken place,
|
|
|
|
unless, in the case of the subject string, you have used the
|
|
|
|
PCRE2_COPY_MATCHED_SUBJECT option, which is described in the section entitled
|
|
|
|
"Option bits for \fBpcre2_match()\fP"
|
2018-10-17 10:33:38 +02:00
|
|
|
.\" HTML <a href="#matchoptions>">
|
|
|
|
.\" </a>
|
|
|
|
below.
|
|
|
|
.\"
|
2014-12-14 18:17:06 +01:00
|
|
|
.P
|
|
|
|
When a match data block itself is no longer needed, it should be freed by
|
2018-08-13 13:57:09 +02:00
|
|
|
calling \fBpcre2_match_data_free()\fP. If this function is called with a NULL
|
2018-06-28 18:26:03 +02:00
|
|
|
argument, it returns immediately, without doing anything.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH "MATCHING A PATTERN: THE TRADITIONAL FUNCTION"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_match(const pcre2_code *\fIcode\fP, PCRE2_SPTR \fIsubject\fP,
|
|
|
|
.B " PCRE2_SIZE \fIlength\fP, PCRE2_SIZE \fIstartoffset\fP,"
|
|
|
|
.B " uint32_t \fIoptions\fP, pcre2_match_data *\fImatch_data\fP,"
|
|
|
|
.B " pcre2_match_context *\fImcontext\fP);"
|
|
|
|
.fi
|
|
|
|
.P
|
|
|
|
The function \fBpcre2_match()\fP is called to match a subject string against a
|
|
|
|
compiled pattern, which is passed in the \fIcode\fP argument. You can call
|
|
|
|
\fBpcre2_match()\fP with the same \fIcode\fP argument as many times as you
|
|
|
|
like, in order to find multiple matches in the subject string or to match
|
|
|
|
different subject strings with the same pattern.
|
|
|
|
.P
|
|
|
|
This function is the main matching facility of the library, and it operates in
|
|
|
|
a Perl-like manner. For specialist use there is also an alternative matching
|
|
|
|
function, which is described
|
|
|
|
.\" HTML <a href="#dfamatch">
|
|
|
|
.\" </a>
|
|
|
|
below
|
|
|
|
.\"
|
|
|
|
in the section about the \fBpcre2_dfa_match()\fP function.
|
|
|
|
.P
|
|
|
|
Here is an example of a simple call to \fBpcre2_match()\fP:
|
|
|
|
.sp
|
|
|
|
pcre2_match_data *md = pcre2_match_data_create(4, NULL);
|
|
|
|
int rc = pcre2_match(
|
|
|
|
re, /* result of pcre2_compile() */
|
|
|
|
"some string", /* the subject string */
|
|
|
|
11, /* the length of the subject string */
|
|
|
|
0, /* start at offset 0 in the subject */
|
|
|
|
0, /* default options */
|
2017-09-25 17:05:29 +02:00
|
|
|
md, /* the match data block */
|
2014-09-19 09:43:39 +02:00
|
|
|
NULL); /* a match context; NULL means use defaults */
|
|
|
|
.sp
|
2014-10-20 19:28:49 +02:00
|
|
|
If the subject string is zero-terminated, the length can be given as
|
|
|
|
PCRE2_ZERO_TERMINATED. A match context must be provided if certain less common
|
2014-09-19 09:43:39 +02:00
|
|
|
matching parameters are to be changed. For details, see the section on
|
|
|
|
.\" HTML <a href="#matchcontext">
|
|
|
|
.\" </a>
|
|
|
|
the match context
|
|
|
|
.\"
|
|
|
|
above.
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.SS "The string to be matched by \fBpcre2_match()\fP"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
The subject string is passed to \fBpcre2_match()\fP as a pointer in
|
|
|
|
\fIsubject\fP, a length in \fIlength\fP, and a starting offset in
|
|
|
|
\fIstartoffset\fP. The length and offset are in code units, not characters.
|
|
|
|
That is, they are in bytes for the 8-bit library, 16-bit code units for the
|
2014-10-20 19:28:49 +02:00
|
|
|
16-bit library, and 32-bit code units for the 32-bit library, whether or not
|
2014-09-19 09:43:39 +02:00
|
|
|
UTF processing is enabled.
|
|
|
|
.P
|
|
|
|
If \fIstartoffset\fP is greater than the length of the subject,
|
|
|
|
\fBpcre2_match()\fP returns PCRE2_ERROR_BADOFFSET. When the starting offset is
|
|
|
|
zero, the search for a match starts at the beginning of the subject, and this
|
|
|
|
is by far the most common case. In UTF-8 or UTF-16 mode, the starting offset
|
|
|
|
must point to the start of a character, or to the end of the subject (in UTF-32
|
|
|
|
mode, one code unit equals one character, so all offsets are valid). Like the
|
2018-06-17 16:13:28 +02:00
|
|
|
pattern string, the subject may contain binary zeros.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
A non-zero starting offset is useful when searching for another match in the
|
|
|
|
same subject by calling \fBpcre2_match()\fP again after a previous success.
|
|
|
|
Setting \fIstartoffset\fP differs from passing over a shortened string and
|
|
|
|
setting PCRE2_NOTBOL in the case of a pattern that begins with any kind of
|
|
|
|
lookbehind. For example, consider the pattern
|
|
|
|
.sp
|
|
|
|
\eBiss\eB
|
|
|
|
.sp
|
|
|
|
which finds occurrences of "iss" in the middle of words. (\eB matches only if
|
|
|
|
the current position in the subject is not a word boundary.) When applied to
|
2021-06-14 12:53:18 +02:00
|
|
|
the string "Mississippi" the first call to \fBpcre2_match()\fP finds the first
|
2014-09-19 09:43:39 +02:00
|
|
|
occurrence. If \fBpcre2_match()\fP is called again with just the remainder of
|
2021-06-14 12:53:18 +02:00
|
|
|
the subject, namely "issippi", it does not match, because \eB is always false
|
|
|
|
at the start of the subject, which is deemed to be a word boundary. However, if
|
2014-09-19 09:43:39 +02:00
|
|
|
\fBpcre2_match()\fP is passed the entire string again, but with
|
|
|
|
\fIstartoffset\fP set to 4, it finds the second occurrence of "iss" because it
|
|
|
|
is able to look behind the starting point to discover that it is preceded by a
|
|
|
|
letter.
|
|
|
|
.P
|
|
|
|
Finding all the matches in a subject is tricky when the pattern can match an
|
|
|
|
empty string. It is possible to emulate Perl's /g behaviour by first trying the
|
|
|
|
match again at the same offset, with the PCRE2_NOTEMPTY_ATSTART and
|
|
|
|
PCRE2_ANCHORED options, and then if that fails, advancing the starting offset
|
|
|
|
and trying an ordinary match again. There is some code that demonstrates how to
|
|
|
|
do this in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2demo\fP
|
|
|
|
.\"
|
|
|
|
sample program. In the most general case, you have to check to see if the
|
|
|
|
newline convention recognizes CRLF as a newline, and if so, and the current
|
|
|
|
character is CR followed by LF, advance the starting offset by two characters
|
|
|
|
instead of one.
|
|
|
|
.P
|
2017-04-20 18:34:35 +02:00
|
|
|
If a non-zero starting offset is passed when the pattern is anchored, a single
|
2014-09-19 09:43:39 +02:00
|
|
|
attempt to match at the given offset is made. This can only succeed if the
|
2017-05-30 12:42:57 +02:00
|
|
|
pattern does not require the match to be at the start of the subject. In other
|
|
|
|
words, the anchoring must be the result of setting the PCRE2_ANCHORED option or
|
2017-03-28 18:34:29 +02:00
|
|
|
the use of .* with PCRE2_DOTALL, not by starting the pattern with ^ or \eA.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.\" HTML <a name="matchoptions"></a>
|
|
|
|
.SS "Option bits for \fBpcre2_match()\fP"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
The unused bits of the \fIoptions\fP argument for \fBpcre2_match()\fP must be
|
2019-03-04 19:07:04 +01:00
|
|
|
zero. The only bits that may be set are PCRE2_ANCHORED,
|
2018-10-17 10:33:38 +02:00
|
|
|
PCRE2_COPY_MATCHED_SUBJECT, PCRE2_ENDANCHORED, PCRE2_NOTBOL, PCRE2_NOTEOL,
|
|
|
|
PCRE2_NOTEMPTY, PCRE2_NOTEMPTY_ATSTART, PCRE2_NO_JIT, PCRE2_NO_UTF_CHECK,
|
|
|
|
PCRE2_PARTIAL_HARD, and PCRE2_PARTIAL_SOFT. Their action is described below.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2017-04-04 19:09:33 +02:00
|
|
|
Setting PCRE2_ANCHORED or PCRE2_ENDANCHORED at match time is not supported by
|
|
|
|
the just-in-time (JIT) compiler. If it is set, JIT matching is disabled and the
|
|
|
|
interpretive code in \fBpcre2_match()\fP is run. Apart from PCRE2_NO_JIT
|
|
|
|
(obviously), the remaining options are supported for JIT matching.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ANCHORED
|
|
|
|
.sp
|
|
|
|
The PCRE2_ANCHORED option limits \fBpcre2_match()\fP to matching at the first
|
|
|
|
matching position. If a pattern was compiled with PCRE2_ANCHORED, or turned out
|
|
|
|
to be anchored by virtue of its contents, it cannot be made unachored at
|
2014-10-20 19:28:49 +02:00
|
|
|
matching time. Note that setting the option at match time disables JIT
|
2014-09-19 09:43:39 +02:00
|
|
|
matching.
|
2018-10-17 10:33:38 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_COPY_MATCHED_SUBJECT
|
|
|
|
.sp
|
2019-03-04 19:07:04 +01:00
|
|
|
By default, a pointer to the subject is remembered in the match data block so
|
|
|
|
that, after a successful match, it can be referenced by the substring
|
2018-10-17 10:33:38 +02:00
|
|
|
extraction functions. This means that the subject's memory must not be freed
|
|
|
|
until all such operations are complete. For some applications where the
|
|
|
|
lifetime of the subject string is not guaranteed, it may be necessary to make a
|
|
|
|
copy of the subject string, but it is wasteful to do this unless the match is
|
|
|
|
successful. After a successful match, if PCRE2_COPY_MATCHED_SUBJECT is set, the
|
|
|
|
subject is copied and the new pointer is remembered in the match data block
|
|
|
|
instead of the original subject pointer. The memory allocator that was used for
|
|
|
|
the match block itself is used. The copy is automatically freed when
|
|
|
|
\fBpcre2_match_data_free()\fP is called to free the match data block. It is also
|
|
|
|
automatically freed if the match data block is re-used for another match
|
|
|
|
operation.
|
2017-04-04 19:09:33 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ENDANCHORED
|
|
|
|
.sp
|
|
|
|
If the PCRE2_ENDANCHORED option is set, any string that \fBpcre2_match()\fP
|
|
|
|
matches must be right at the end of the subject string. Note that setting the
|
|
|
|
option at match time disables JIT matching.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_NOTBOL
|
|
|
|
.sp
|
|
|
|
This option specifies that first character of the subject string is not the
|
|
|
|
beginning of a line, so the circumflex metacharacter should not match before
|
2014-11-21 17:45:06 +01:00
|
|
|
it. Setting this without having set PCRE2_MULTILINE at compile time causes
|
|
|
|
circumflex never to match. This option affects only the behaviour of the
|
|
|
|
circumflex metacharacter. It does not affect \eA.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_NOTEOL
|
|
|
|
.sp
|
|
|
|
This option specifies that the end of the subject string is not the end of a
|
|
|
|
line, so the dollar metacharacter should not match it nor (except in multiline
|
2014-11-21 17:45:06 +01:00
|
|
|
mode) a newline immediately before it. Setting this without having set
|
|
|
|
PCRE2_MULTILINE at compile time causes dollar never to match. This option
|
|
|
|
affects only the behaviour of the dollar metacharacter. It does not affect \eZ
|
|
|
|
or \ez.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_NOTEMPTY
|
|
|
|
.sp
|
|
|
|
An empty string is not considered to be a valid match if this option is set. If
|
|
|
|
there are alternatives in the pattern, they are tried. If all the alternatives
|
|
|
|
match the empty string, the entire match fails. For example, if the pattern
|
|
|
|
.sp
|
|
|
|
a?b?
|
|
|
|
.sp
|
|
|
|
is applied to a string not beginning with "a" or "b", it matches an empty
|
|
|
|
string at the start of the subject. With PCRE2_NOTEMPTY set, this match is not
|
2014-11-21 17:45:06 +01:00
|
|
|
valid, so \fBpcre2_match()\fP searches further into the string for occurrences
|
|
|
|
of "a" or "b".
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_NOTEMPTY_ATSTART
|
|
|
|
.sp
|
2014-11-21 17:45:06 +01:00
|
|
|
This is like PCRE2_NOTEMPTY, except that it locks out an empty string match
|
|
|
|
only at the first matching position, that is, at the start of the subject plus
|
|
|
|
the starting offset. An empty string match later in the subject is permitted.
|
|
|
|
If the pattern is anchored, such a match can occur only if the pattern contains
|
|
|
|
\eK.
|
2016-06-05 18:05:34 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_NO_JIT
|
|
|
|
.sp
|
|
|
|
By default, if a pattern has been successfully processed by
|
|
|
|
\fBpcre2_jit_compile()\fP, JIT is automatically used when \fBpcre2_match()\fP
|
|
|
|
is called with options that JIT supports. Setting PCRE2_NO_JIT disables the use
|
|
|
|
of JIT; it forces matching to be done by the interpreter.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_NO_UTF_CHECK
|
|
|
|
.sp
|
|
|
|
When PCRE2_UTF is set at compile time, the validity of the subject as a UTF
|
2019-05-24 19:15:48 +02:00
|
|
|
string is checked unless PCRE2_NO_UTF_CHECK is passed to \fBpcre2_match()\fP or
|
|
|
|
PCRE2_MATCH_INVALID_UTF was passed to \fBpcre2_compile()\fP. The latter special
|
|
|
|
case is discussed in detail in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2unicode\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
|
|
|
.P
|
|
|
|
In the default case, if a non-zero starting offset is given, the check is
|
|
|
|
applied only to that part of the subject that could be inspected during
|
|
|
|
matching, and there is a check that the starting offset points to the first
|
|
|
|
code unit of a character or to the end of the subject. If there are no
|
|
|
|
lookbehind assertions in the pattern, the check starts at the starting offset.
|
|
|
|
Otherwise, it starts at the length of the longest lookbehind before the
|
|
|
|
starting offset, or at the start of the subject if there are not that many
|
|
|
|
characters before the starting offset. Note that the sequences \eb and \eB are
|
|
|
|
one-character lookbehinds.
|
2015-08-18 12:34:05 +02:00
|
|
|
.P
|
|
|
|
The check is carried out before any other processing takes place, and a
|
2014-09-19 09:43:39 +02:00
|
|
|
negative error code is returned if the check fails. There are several UTF error
|
|
|
|
codes for each code unit width, corresponding to different problems with the
|
2015-08-18 12:34:05 +02:00
|
|
|
code unit sequence. There are discussions about the validity of
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HTML <a href="pcre2unicode.html#utf8strings">
|
|
|
|
.\" </a>
|
|
|
|
UTF-8 strings,
|
|
|
|
.\"
|
|
|
|
.\" HTML <a href="pcre2unicode.html#utf16strings">
|
|
|
|
.\" </a>
|
|
|
|
UTF-16 strings,
|
|
|
|
.\"
|
|
|
|
and
|
|
|
|
.\" HTML <a href="pcre2unicode.html#utf32strings">
|
|
|
|
.\" </a>
|
|
|
|
UTF-32 strings
|
|
|
|
.\"
|
|
|
|
in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2unicode\fP
|
|
|
|
.\"
|
2019-05-24 19:15:48 +02:00
|
|
|
documentation.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2019-05-24 19:15:48 +02:00
|
|
|
If you know that your subject is valid, and you want to skip this check for
|
2014-09-19 09:43:39 +02:00
|
|
|
performance reasons, you can set the PCRE2_NO_UTF_CHECK option when calling
|
|
|
|
\fBpcre2_match()\fP. You might want to do this for the second and subsequent
|
2019-05-24 19:15:48 +02:00
|
|
|
calls to \fBpcre2_match()\fP if you are making repeated calls to find multiple
|
2017-03-28 18:34:29 +02:00
|
|
|
matches in the same subject string.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2019-05-24 19:15:48 +02:00
|
|
|
\fBWarning:\fP Unless PCRE2_MATCH_INVALID_UTF was set at compile time, when
|
|
|
|
PCRE2_NO_UTF_CHECK is set at match time the effect of passing an invalid
|
2017-03-28 18:34:29 +02:00
|
|
|
string as a subject, or an invalid value of \fIstartoffset\fP, is undefined.
|
2019-05-24 19:15:48 +02:00
|
|
|
Your program may crash or loop indefinitely or give wrong results.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_PARTIAL_HARD
|
|
|
|
PCRE2_PARTIAL_SOFT
|
|
|
|
.sp
|
|
|
|
These options turn on the partial matching feature. A partial match occurs if
|
|
|
|
the end of the subject string is reached successfully, but there are not enough
|
2019-10-17 18:39:38 +02:00
|
|
|
subject characters to complete the match. In addition, either at least one
|
|
|
|
character must have been inspected or the pattern must contain a lookbehind, or
|
2019-07-22 18:30:44 +02:00
|
|
|
the pattern must be one that could match an empty string.
|
2019-07-21 18:48:13 +02:00
|
|
|
.P
|
|
|
|
If this situation arises when PCRE2_PARTIAL_SOFT (but not PCRE2_PARTIAL_HARD)
|
|
|
|
is set, matching continues by testing any remaining alternatives. Only if no
|
|
|
|
complete match can be found is PCRE2_ERROR_PARTIAL returned instead of
|
|
|
|
PCRE2_ERROR_NOMATCH. In other words, PCRE2_PARTIAL_SOFT specifies that the
|
|
|
|
caller is prepared to handle a partial match, but only if no complete match can
|
|
|
|
be found.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
If PCRE2_PARTIAL_HARD is set, it overrides PCRE2_PARTIAL_SOFT. In this case, if
|
|
|
|
a partial match is found, \fBpcre2_match()\fP immediately returns
|
|
|
|
PCRE2_ERROR_PARTIAL, without considering any other alternatives. In other
|
|
|
|
words, when PCRE2_PARTIAL_HARD is set, a partial match is considered to be more
|
|
|
|
important that an alternative complete match.
|
|
|
|
.P
|
|
|
|
There is a more detailed discussion of partial and multi-segment matching, with
|
|
|
|
examples, in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2partial\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH "NEWLINE HANDLING WHEN MATCHING"
|
|
|
|
.rs
|
2014-10-20 19:28:49 +02:00
|
|
|
.sp
|
|
|
|
When PCRE2 is built, a default newline convention is set; this is usually the
|
|
|
|
standard convention for the operating system. The default can be overridden in
|
2014-11-14 19:41:20 +01:00
|
|
|
a
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HTML <a href="#compilecontext">
|
|
|
|
.\" </a>
|
2015-12-17 19:44:06 +01:00
|
|
|
compile context
|
|
|
|
.\"
|
|
|
|
by calling \fBpcre2_set_newline()\fP. It can also be overridden by starting a
|
|
|
|
pattern string with, for example, (*CRLF), as described in the
|
|
|
|
.\" HTML <a href="pcre2pattern.html#newlines">
|
|
|
|
.\" </a>
|
|
|
|
section on newline conventions
|
2014-09-19 09:43:39 +02:00
|
|
|
.\"
|
2015-12-17 19:44:06 +01:00
|
|
|
in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2pattern\fP
|
|
|
|
.\"
|
|
|
|
page. During matching, the newline choice affects the behaviour of the dot,
|
2014-09-19 09:43:39 +02:00
|
|
|
circumflex, and dollar metacharacters. It may also alter the way the match
|
2014-11-21 17:45:06 +01:00
|
|
|
starting position is advanced after a match failure for an unanchored pattern.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2014-11-21 17:45:06 +01:00
|
|
|
When PCRE2_NEWLINE_CRLF, PCRE2_NEWLINE_ANYCRLF, or PCRE2_NEWLINE_ANY is set as
|
|
|
|
the newline convention, and a match attempt for an unanchored pattern fails
|
|
|
|
when the current starting position is at a CRLF sequence, and the pattern
|
|
|
|
contains no explicit matches for CR or LF characters, the match position is
|
|
|
|
advanced by two characters instead of one, in other words, to after the CRLF.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
The above rule is a compromise that makes the most common cases work as
|
|
|
|
expected. For example, if the pattern is .+A (and the PCRE2_DOTALL option is
|
|
|
|
not set), it does not match the string "\er\enA" because, after failing at the
|
|
|
|
start, it skips both the CR and the LF before retrying. However, the pattern
|
|
|
|
[\er\en]A does match that string, because it contains an explicit CR or LF
|
|
|
|
reference, and so advances only by one character after the first failure.
|
|
|
|
.P
|
|
|
|
An explicit match for CR of LF is either a literal appearance of one of those
|
2017-05-30 12:42:57 +02:00
|
|
|
characters in the pattern, or one of the \er or \en or equivalent octal or
|
2017-03-28 18:34:29 +02:00
|
|
|
hexadecimal escape sequences. Implicit matches such as [^X] do not count, nor
|
|
|
|
does \es, even though it includes CR and LF in the characters that it matches.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
Notwithstanding the above, anomalous effects may still occur when CRLF is a
|
|
|
|
valid newline sequence and explicit \er or \en escapes appear in the pattern.
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.\" HTML <a name="matchedstrings"></a>
|
|
|
|
.SH "HOW PCRE2_MATCH() RETURNS A STRING AND CAPTURED SUBSTRINGS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B uint32_t pcre2_get_ovector_count(pcre2_match_data *\fImatch_data\fP);
|
|
|
|
.sp
|
|
|
|
.B PCRE2_SIZE *pcre2_get_ovector_pointer(pcre2_match_data *\fImatch_data\fP);
|
|
|
|
.fi
|
|
|
|
.P
|
|
|
|
In general, a pattern matches a certain portion of the subject, and in
|
2014-10-20 19:28:49 +02:00
|
|
|
addition, further substrings from the subject may be picked out by
|
2014-09-19 09:43:39 +02:00
|
|
|
parenthesized parts of the pattern. Following the usage in Jeffrey Friedl's
|
2019-02-06 19:11:36 +01:00
|
|
|
book, this is called "capturing" in what follows, and the phrase "capture
|
|
|
|
group" (Perl terminology) is used for a fragment of a pattern that picks out a
|
|
|
|
substring. PCRE2 supports several other kinds of parenthesized group that do
|
|
|
|
not cause substrings to be captured. The \fBpcre2_pattern_info()\fP function
|
|
|
|
can be used to find out how many capture groups there are in a compiled
|
|
|
|
pattern.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2015-12-17 19:44:06 +01:00
|
|
|
You can use auxiliary functions for accessing captured substrings
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HTML <a href="#extractbynumber">
|
|
|
|
.\" </a>
|
|
|
|
by number
|
|
|
|
.\"
|
|
|
|
or
|
|
|
|
.\" HTML <a href="#extractbyname">
|
|
|
|
.\" </a>
|
2015-12-17 19:44:06 +01:00
|
|
|
by name,
|
|
|
|
.\"
|
|
|
|
as described in sections below.
|
|
|
|
.P
|
|
|
|
Alternatively, you can make direct use of the vector of PCRE2_SIZE values,
|
|
|
|
called the \fBovector\fP, which contains the offsets of captured strings. It is
|
|
|
|
part of the
|
|
|
|
.\" HTML <a href="#matchdatablock">
|
|
|
|
.\" </a>
|
|
|
|
match data block.
|
2014-09-19 09:43:39 +02:00
|
|
|
.\"
|
2015-12-17 19:44:06 +01:00
|
|
|
The function \fBpcre2_get_ovector_pointer()\fP returns the address of the
|
|
|
|
ovector, and \fBpcre2_get_ovector_count()\fP returns the number of pairs of
|
|
|
|
values it contains.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
Within the ovector, the first in each pair of values is set to the offset of
|
|
|
|
the first code unit of a substring, and the second is set to the offset of the
|
|
|
|
first code unit after the end of a substring. These values are always code unit
|
|
|
|
offsets, not character offsets. That is, they are byte offsets in the 8-bit
|
|
|
|
library, 16-bit offsets in the 16-bit library, and 32-bit offsets in the 32-bit
|
|
|
|
library.
|
|
|
|
.P
|
2014-12-22 18:33:10 +01:00
|
|
|
After a partial match (error return PCRE2_ERROR_PARTIAL), only the first pair
|
|
|
|
of offsets (that is, \fIovector[0]\fP and \fIovector[1]\fP) are set. They
|
|
|
|
identify the part of the subject that was partially matched. See the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2partial\fP
|
|
|
|
.\"
|
|
|
|
documentation for details of partial matching.
|
|
|
|
.P
|
2017-03-28 18:34:29 +02:00
|
|
|
After a fully successful match, the first pair of offsets identifies the
|
|
|
|
portion of the subject string that was matched by the entire pattern. The next
|
|
|
|
pair is used for the first captured substring, and so on. The value returned by
|
2014-12-22 18:33:10 +01:00
|
|
|
\fBpcre2_match()\fP is one more than the highest numbered pair that has been
|
|
|
|
set. For example, if two substrings have been captured, the returned value is
|
2017-03-28 18:34:29 +02:00
|
|
|
3. If there are no captured substrings, the return value from a successful
|
2014-12-22 18:33:10 +01:00
|
|
|
match is 1, indicating that just the first pair of offsets has been set.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2014-12-19 10:55:25 +01:00
|
|
|
If a pattern uses the \eK escape sequence within a positive assertion, the
|
2014-12-22 18:33:10 +01:00
|
|
|
reported start of a successful match can be greater than the end of the match.
|
|
|
|
For example, if the pattern (?=ab\eK) is matched against "ab", the start and
|
|
|
|
end offset values for the match are 2 and 0.
|
2014-12-14 18:17:06 +01:00
|
|
|
.P
|
2019-02-06 19:11:36 +01:00
|
|
|
If a capture group is matched repeatedly within a single match operation, it is
|
|
|
|
the last portion of the subject that it matched that is returned.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
If the ovector is too small to hold all the captured substring offsets, as much
|
2014-10-05 19:55:25 +02:00
|
|
|
as possible is filled in, and the function returns a value of zero. If captured
|
|
|
|
substrings are not of interest, \fBpcre2_match()\fP may be called with a match
|
2017-03-28 18:34:29 +02:00
|
|
|
data block whose ovector is of minimum length (that is, one pair).
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2019-02-06 19:11:36 +01:00
|
|
|
It is possible for capture group number \fIn+1\fP to match some part of the
|
|
|
|
subject when group \fIn\fP has not been used at all. For example, if the string
|
|
|
|
"abc" is matched against the pattern (a|(z))(bc) the return from the function
|
|
|
|
is 4, and groups 1 and 3 are matched, but 2 is not. When this happens, both
|
|
|
|
values in the offset pairs corresponding to unused groups are set to
|
2014-09-19 09:43:39 +02:00
|
|
|
PCRE2_UNSET.
|
|
|
|
.P
|
2019-02-06 19:11:36 +01:00
|
|
|
Offset values that correspond to unused groups at the end of the expression are
|
|
|
|
also set to PCRE2_UNSET. For example, if the string "abc" is matched against
|
|
|
|
the pattern (abc)(x(yz)?)? groups 2 and 3 are not matched. The return from the
|
|
|
|
function is 2, because the highest used capture group number is 1. The offsets
|
|
|
|
for for the second and third capture groupss (assuming the vector is large
|
|
|
|
enough, of course) are set to PCRE2_UNSET.
|
|
|
|
.P
|
2014-09-19 09:43:39 +02:00
|
|
|
Elements in the ovector that do not correspond to capturing parentheses in the
|
|
|
|
pattern are never changed. That is, if a pattern contains \fIn\fP capturing
|
|
|
|
parentheses, no more than \fIovector[0]\fP to \fIovector[2n+1]\fP are set by
|
|
|
|
\fBpcre2_match()\fP. The other elements retain whatever values they previously
|
2018-09-07 17:56:36 +02:00
|
|
|
had. After a failed match attempt, the contents of the ovector are unchanged.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.\" HTML <a name="matchotherdata"></a>
|
2014-11-21 17:45:06 +01:00
|
|
|
.SH "OTHER INFORMATION ABOUT A MATCH"
|
2014-09-19 09:43:39 +02:00
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B PCRE2_SPTR pcre2_get_mark(pcre2_match_data *\fImatch_data\fP);
|
|
|
|
.sp
|
|
|
|
.B PCRE2_SIZE pcre2_get_startchar(pcre2_match_data *\fImatch_data\fP);
|
|
|
|
.fi
|
|
|
|
.P
|
2014-11-21 17:45:06 +01:00
|
|
|
As well as the offsets in the ovector, other information about a match is
|
2014-12-22 18:33:10 +01:00
|
|
|
retained in the match data block and can be retrieved by the above functions in
|
|
|
|
appropriate circumstances. If they are called at other times, the result is
|
|
|
|
undefined.
|
|
|
|
.P
|
|
|
|
After a successful match, a partial match (PCRE2_ERROR_PARTIAL), or a failure
|
2018-11-27 17:41:20 +01:00
|
|
|
to match (PCRE2_ERROR_NOMATCH), a mark name may be available. The function
|
2019-03-04 19:07:04 +01:00
|
|
|
\fBpcre2_get_mark()\fP can be called to access this name, which can be
|
|
|
|
specified in the pattern by any of the backtracking control verbs, not just
|
2018-11-27 17:41:20 +01:00
|
|
|
(*MARK). The same function applies to all the verbs. It returns a pointer to
|
|
|
|
the zero-terminated name, which is within the compiled pattern. If no name is
|
2017-10-13 18:26:24 +02:00
|
|
|
available, NULL is returned. The length of the name (excluding the terminating
|
|
|
|
zero) is stored in the code unit that precedes the name. You should use this
|
|
|
|
length instead of relying on the terminating zero if the name might contain a
|
|
|
|
binary zero.
|
|
|
|
.P
|
2018-11-27 17:41:20 +01:00
|
|
|
After a successful match, the name that is returned is the last mark name
|
|
|
|
encountered on the matching path through the pattern. Instances of backtracking
|
|
|
|
verbs without names do not count. Thus, for example, if the matching path
|
|
|
|
contains (*MARK:A)(*PRUNE), the name "A" is returned. After a "no match" or a
|
|
|
|
partial match, the last encountered name is returned. For example, consider
|
|
|
|
this pattern:
|
2014-12-22 18:33:10 +01:00
|
|
|
.sp
|
|
|
|
^(*MARK:A)((*MARK:B)a|b)c
|
|
|
|
.sp
|
2017-10-13 18:26:24 +02:00
|
|
|
When it matches "bc", the returned name is A. The B mark is "seen" in the first
|
2014-12-22 18:33:10 +01:00
|
|
|
branch of the group, but it is not on the matching path. On the other hand,
|
2017-10-13 18:26:24 +02:00
|
|
|
when this pattern fails to match "bx", the returned name is B.
|
2014-12-22 18:33:10 +01:00
|
|
|
.P
|
2018-06-18 18:49:12 +02:00
|
|
|
\fBWarning:\fP By default, certain start-of-match optimizations are used to
|
|
|
|
give a fast "no match" result in some situations. For example, if the anchoring
|
|
|
|
is removed from the pattern above, there is an initial check for the presence
|
|
|
|
of "c" in the subject before running the matching engine. This check fails for
|
|
|
|
"bx", causing a match failure without seeing any marks. You can disable the
|
|
|
|
start-of-match optimizations by setting the PCRE2_NO_START_OPTIMIZE option for
|
2018-11-27 17:41:20 +01:00
|
|
|
\fBpcre2_compile()\fP or by starting the pattern with (*NO_START_OPT).
|
2018-06-18 18:49:12 +02:00
|
|
|
.P
|
2014-12-22 18:33:10 +01:00
|
|
|
After a successful match, a partial match, or one of the invalid UTF errors
|
|
|
|
(for example, PCRE2_ERROR_UTF8_ERR5), \fBpcre2_get_startchar()\fP can be
|
|
|
|
called. After a successful or partial match it returns the code unit offset of
|
|
|
|
the character at which the match started. For a non-partial match, this can be
|
2014-10-25 17:51:01 +02:00
|
|
|
different to the value of \fIovector[0]\fP if the pattern contains the \eK
|
2014-11-03 18:13:00 +01:00
|
|
|
escape sequence. After a partial match, however, this value is always the same
|
2014-10-25 17:51:01 +02:00
|
|
|
as \fIovector[0]\fP because \eK does not affect the result of a partial match.
|
2014-11-23 19:38:38 +01:00
|
|
|
.P
|
2015-12-17 19:44:06 +01:00
|
|
|
After a UTF check failure, \fBpcre2_get_startchar()\fP can be used to obtain
|
2014-12-22 18:33:10 +01:00
|
|
|
the code unit offset of the invalid UTF character. Details are given in the
|
2014-11-23 19:38:38 +01:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2unicode\fP
|
|
|
|
.\"
|
2014-11-24 16:31:28 +01:00
|
|
|
page.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.\" HTML <a name="errorlist"></a>
|
2014-11-21 17:45:06 +01:00
|
|
|
.SH "ERROR RETURNS FROM \fBpcre2_match()\fP"
|
2014-09-19 09:43:39 +02:00
|
|
|
.rs
|
|
|
|
.sp
|
2014-10-20 19:28:49 +02:00
|
|
|
If \fBpcre2_match()\fP fails, it returns a negative number. This can be
|
2016-06-17 13:30:27 +02:00
|
|
|
converted to a text string by calling the \fBpcre2_get_error_message()\fP
|
|
|
|
function (see "Obtaining a textual error message"
|
|
|
|
.\" HTML <a href="#geterrormessage">
|
|
|
|
.\" </a>
|
|
|
|
below).
|
|
|
|
.\"
|
|
|
|
Negative error codes are also returned by other functions, and are documented
|
|
|
|
with them. The codes are given names in the header file. If UTF checking is in
|
|
|
|
force and an invalid UTF subject string is detected, one of a number of
|
|
|
|
UTF-specific negative error codes is returned. Details are given in the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2unicode\fP
|
|
|
|
.\"
|
|
|
|
page. The following are the other errors that may be returned by
|
|
|
|
\fBpcre2_match()\fP:
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_NOMATCH
|
|
|
|
.sp
|
|
|
|
The subject string did not match the pattern.
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_PARTIAL
|
|
|
|
.sp
|
|
|
|
The subject string did not match, but it did match partially. See the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2partial\fP
|
|
|
|
.\"
|
|
|
|
documentation for details of partial matching.
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_BADMAGIC
|
|
|
|
.sp
|
|
|
|
PCRE2 stores a 4-byte "magic number" at the start of the compiled code, to
|
|
|
|
catch the case when it is passed a junk pointer. This is the error that is
|
|
|
|
returned when the magic number is not present.
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_BADMODE
|
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
This error is given when a compiled pattern is passed to a function in a
|
|
|
|
library of a different code unit width, for example, a pattern compiled by
|
|
|
|
the 8-bit library is passed to a 16-bit or 32-bit library function.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_BADOFFSET
|
|
|
|
.sp
|
2014-11-21 17:45:06 +01:00
|
|
|
The value of \fIstartoffset\fP was greater than the length of the subject.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_BADOPTION
|
|
|
|
.sp
|
|
|
|
An unrecognized bit was set in the \fIoptions\fP argument.
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_BADUTFOFFSET
|
|
|
|
.sp
|
|
|
|
The UTF code unit sequence that was passed as a subject was checked and found
|
|
|
|
to be valid (the PCRE2_NO_UTF_CHECK option was not set), but the value of
|
|
|
|
\fIstartoffset\fP did not point to the beginning of a UTF character or the end
|
|
|
|
of the subject.
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_CALLOUT
|
|
|
|
.sp
|
|
|
|
This error is never generated by \fBpcre2_match()\fP itself. It is provided for
|
2015-06-18 18:39:25 +02:00
|
|
|
use by callout functions that want to cause \fBpcre2_match()\fP or
|
2015-03-23 16:52:08 +01:00
|
|
|
\fBpcre2_callout_enumerate()\fP to return a distinctive error code. See the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2callout\fP
|
|
|
|
.\"
|
|
|
|
documentation for details.
|
2017-03-28 18:34:29 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_DEPTHLIMIT
|
|
|
|
.sp
|
|
|
|
The nested backtracking depth limit was reached.
|
2017-04-20 18:34:35 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_HEAPLIMIT
|
|
|
|
.sp
|
|
|
|
The heap limit was reached.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_INTERNAL
|
|
|
|
.sp
|
|
|
|
An unexpected internal error has occurred. This error could be caused by a bug
|
|
|
|
in PCRE2 or by overwriting of the compiled pattern.
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_JIT_STACKLIMIT
|
|
|
|
.sp
|
|
|
|
This error is returned when a pattern that was successfully studied using JIT
|
|
|
|
is being matched, but the memory available for the just-in-time processing
|
|
|
|
stack is not large enough. See the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2jit\fP
|
|
|
|
.\"
|
|
|
|
documentation for more details.
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_MATCHLIMIT
|
|
|
|
.sp
|
2017-03-28 18:34:29 +02:00
|
|
|
The backtracking match limit was reached.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_NOMEMORY
|
|
|
|
.sp
|
2017-05-30 12:42:57 +02:00
|
|
|
If a pattern contains many nested backtracking points, heap memory is used to
|
|
|
|
remember them. This error is given when the memory allocation function (default
|
|
|
|
or custom) fails. Note that a different error, PCRE2_ERROR_HEAPLIMIT, is given
|
2019-03-04 19:07:04 +01:00
|
|
|
if the amount of memory needed exceeds the heap limit. PCRE2_ERROR_NOMEMORY is
|
2018-10-17 10:33:38 +02:00
|
|
|
also returned if PCRE2_COPY_MATCHED_SUBJECT is set and memory allocation fails.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_NULL
|
|
|
|
.sp
|
|
|
|
Either the \fIcode\fP, \fIsubject\fP, or \fImatch_data\fP argument was passed
|
|
|
|
as NULL.
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_RECURSELOOP
|
|
|
|
.sp
|
|
|
|
This error is returned when \fBpcre2_match()\fP detects a recursion loop within
|
|
|
|
the pattern. Specifically, it means that either the whole pattern or a
|
2019-02-06 19:11:36 +01:00
|
|
|
capture group has been called recursively for the second time at the same
|
|
|
|
position in the subject string. Some simple patterns that might do this are
|
|
|
|
detected and faulted at compile time, but more complicated cases, in particular
|
|
|
|
mutual recursions between two different groups, cannot be detected until
|
|
|
|
matching is attempted.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
2016-06-17 13:30:27 +02:00
|
|
|
.\" HTML <a name="geterrormessage"></a>
|
|
|
|
.SH "OBTAINING A TEXTUAL ERROR MESSAGE"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_get_error_message(int \fIerrorcode\fP, PCRE2_UCHAR *\fIbuffer\fP,
|
|
|
|
.B " PCRE2_SIZE \fIbufflen\fP);"
|
|
|
|
.fi
|
|
|
|
.P
|
2016-06-29 18:52:05 +02:00
|
|
|
A text message for an error code from any PCRE2 function (compile, match, or
|
|
|
|
auxiliary) can be obtained by calling \fBpcre2_get_error_message()\fP. The code
|
|
|
|
is passed as the first argument, with the remaining two arguments specifying a
|
2017-03-21 18:46:21 +01:00
|
|
|
code unit buffer and its length in code units, into which the text message is
|
|
|
|
placed. The message is returned in code units of the appropriate width for the
|
2016-06-29 18:52:05 +02:00
|
|
|
library that is being used.
|
2016-06-17 13:30:27 +02:00
|
|
|
.P
|
|
|
|
The returned message is terminated with a trailing zero, and the function
|
|
|
|
returns the number of code units used, excluding the trailing zero. If the
|
|
|
|
error number is unknown, the negative error code PCRE2_ERROR_BADDATA is
|
|
|
|
returned. If the buffer is too small, the message is truncated (but still with
|
|
|
|
a trailing zero), and the negative error code PCRE2_ERROR_NOMEMORY is returned.
|
|
|
|
None of the messages are very long; a buffer size of 120 code units is ample.
|
|
|
|
.
|
|
|
|
.
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HTML <a name="extractbynumber"></a>
|
|
|
|
.SH "EXTRACTING CAPTURED SUBSTRINGS BY NUMBER"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_substring_length_bynumber(pcre2_match_data *\fImatch_data\fP,
|
2014-12-01 17:14:53 +01:00
|
|
|
.B " uint32_t \fInumber\fP, PCRE2_SIZE *\fIlength\fP);"
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
.B int pcre2_substring_copy_bynumber(pcre2_match_data *\fImatch_data\fP,
|
2014-12-01 17:14:53 +01:00
|
|
|
.B " uint32_t \fInumber\fP, PCRE2_UCHAR *\fIbuffer\fP,"
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " PCRE2_SIZE *\fIbufflen\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_substring_get_bynumber(pcre2_match_data *\fImatch_data\fP,
|
2014-12-01 17:14:53 +01:00
|
|
|
.B " uint32_t \fInumber\fP, PCRE2_UCHAR **\fIbufferptr\fP,"
|
2014-09-19 09:43:39 +02:00
|
|
|
.B " PCRE2_SIZE *\fIbufflen\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_substring_free(PCRE2_UCHAR *\fIbuffer\fP);
|
|
|
|
.fi
|
|
|
|
.P
|
|
|
|
Captured substrings can be accessed directly by using the ovector as described
|
|
|
|
.\" HTML <a href="#matchedstrings">
|
|
|
|
.\" </a>
|
|
|
|
above.
|
|
|
|
.\"
|
|
|
|
For convenience, auxiliary functions are provided for extracting captured
|
2014-12-22 18:33:10 +01:00
|
|
|
substrings as new, separate, zero-terminated strings. A substring that contains
|
|
|
|
a binary zero is correctly extracted and has a further zero added on the end,
|
|
|
|
but the result is not, of course, a C string.
|
|
|
|
.P
|
|
|
|
The functions in this section identify substrings by number. The number zero
|
|
|
|
refers to the entire matched substring, with higher numbers referring to
|
|
|
|
substrings captured by parenthesized groups. After a partial match, only
|
|
|
|
substring zero is available. An attempt to extract any other substring gives
|
|
|
|
the error PCRE2_ERROR_PARTIAL. The next section describes similar functions for
|
|
|
|
extracting captured substrings by name.
|
2014-12-14 18:17:06 +01:00
|
|
|
.P
|
2014-12-19 10:55:25 +01:00
|
|
|
If a pattern uses the \eK escape sequence within a positive assertion, the
|
2014-12-22 18:33:10 +01:00
|
|
|
reported start of a successful match can be greater than the end of the match.
|
|
|
|
For example, if the pattern (?=ab\eK) is matched against "ab", the start and
|
|
|
|
end offset values for the match are 2 and 0. In this situation, calling these
|
2014-12-14 18:17:06 +01:00
|
|
|
functions with a zero substring number extracts a zero-length empty string.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
You can find the length in code units of a captured substring without
|
|
|
|
extracting it by calling \fBpcre2_substring_length_bynumber()\fP. The first
|
|
|
|
argument is a pointer to the match data block, the second is the group number,
|
2014-12-19 10:55:25 +01:00
|
|
|
and the third is a pointer to a variable into which the length is placed. If
|
|
|
|
you just want to know whether or not the substring has been captured, you can
|
2014-12-14 18:17:06 +01:00
|
|
|
pass the third argument as NULL.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2014-12-14 18:17:06 +01:00
|
|
|
The \fBpcre2_substring_copy_bynumber()\fP function copies a captured substring
|
|
|
|
into a supplied buffer, whereas \fBpcre2_substring_get_bynumber()\fP copies it
|
|
|
|
into new memory, obtained using the same memory allocation function that was
|
|
|
|
used for the match data block. The first two arguments of these functions are a
|
2019-02-06 19:11:36 +01:00
|
|
|
pointer to the match data block and a capture group number.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
The final arguments of \fBpcre2_substring_copy_bynumber()\fP are a pointer to
|
|
|
|
the buffer and a pointer to a variable that contains its length in code units.
|
2014-11-21 17:45:06 +01:00
|
|
|
This is updated to contain the actual number of code units used for the
|
|
|
|
extracted substring, excluding the terminating zero.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2014-10-20 19:28:49 +02:00
|
|
|
For \fBpcre2_substring_get_bynumber()\fP the third and fourth arguments point
|
|
|
|
to variables that are updated with a pointer to the new memory and the number
|
|
|
|
of code units that comprise the substring, again excluding the terminating
|
|
|
|
zero. When the substring is no longer needed, the memory should be freed by
|
2014-09-19 09:43:39 +02:00
|
|
|
calling \fBpcre2_substring_free()\fP.
|
|
|
|
.P
|
2014-12-14 18:17:06 +01:00
|
|
|
The return value from all these functions is zero for success, or a negative
|
|
|
|
error code. If the pattern match failed, the match failure code is returned.
|
2014-12-22 18:33:10 +01:00
|
|
|
If a substring number greater than zero is used after a partial match,
|
|
|
|
PCRE2_ERROR_PARTIAL is returned. Other possible error codes are:
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_NOMEMORY
|
|
|
|
.sp
|
|
|
|
The buffer was too small for \fBpcre2_substring_copy_bynumber()\fP, or the
|
|
|
|
attempt to get memory failed for \fBpcre2_substring_get_bynumber()\fP.
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_NOSUBSTRING
|
|
|
|
.sp
|
2014-12-19 10:55:25 +01:00
|
|
|
There is no substring with that number in the pattern, that is, the number is
|
2014-12-13 18:43:26 +01:00
|
|
|
greater than the number of capturing parentheses.
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_UNAVAILABLE
|
|
|
|
.sp
|
2014-12-19 10:55:25 +01:00
|
|
|
The substring number, though not greater than the number of captures in the
|
|
|
|
pattern, is greater than the number of slots in the ovector, so the substring
|
2014-12-13 18:43:26 +01:00
|
|
|
could not be captured.
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_UNSET
|
|
|
|
.sp
|
|
|
|
The substring did not participate in the match. For example, if the pattern is
|
2014-12-14 18:17:06 +01:00
|
|
|
(abc)|(def) and the subject is "def", and the ovector contains at least two
|
|
|
|
capturing slots, substring number 1 is unset.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH "EXTRACTING A LIST OF ALL CAPTURED SUBSTRINGS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_substring_list_get(pcre2_match_data *\fImatch_data\fP,
|
|
|
|
.B " PCRE2_UCHAR ***\fIlistptr\fP, PCRE2_SIZE **\fIlengthsptr\fP);
|
|
|
|
.sp
|
|
|
|
.B void pcre2_substring_list_free(PCRE2_SPTR *\fIlist\fP);
|
|
|
|
.fi
|
|
|
|
.P
|
|
|
|
The \fBpcre2_substring_list_get()\fP function extracts all available substrings
|
2014-11-21 17:45:06 +01:00
|
|
|
and builds a list of pointers to them. It also (optionally) builds a second
|
|
|
|
list that contains their lengths (in code units), excluding a terminating zero
|
|
|
|
that is added to each of them. All this is done in a single block of memory
|
|
|
|
that is obtained using the same memory allocation function that was used to get
|
|
|
|
the match data block.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2014-12-22 18:33:10 +01:00
|
|
|
This function must be called only after a successful match. If called after a
|
|
|
|
partial match, the error code PCRE2_ERROR_PARTIAL is returned.
|
|
|
|
.P
|
2014-09-19 09:43:39 +02:00
|
|
|
The address of the memory block is returned via \fIlistptr\fP, which is also
|
|
|
|
the start of the list of string pointers. The end of the list is marked by a
|
|
|
|
NULL pointer. The address of the list of lengths is returned via
|
|
|
|
\fIlengthsptr\fP. If your strings do not contain binary zeros and you do not
|
|
|
|
therefore need the lengths, you may supply NULL as the \fBlengthsptr\fP
|
|
|
|
argument to disable the creation of a list of lengths. The yield of the
|
|
|
|
function is zero if all went well, or PCRE2_ERROR_NOMEMORY if the memory block
|
2014-10-20 19:28:49 +02:00
|
|
|
could not be obtained. When the list is no longer needed, it should be freed by
|
2014-09-19 09:43:39 +02:00
|
|
|
calling \fBpcre2_substring_list_free()\fP.
|
|
|
|
.P
|
|
|
|
If this function encounters a substring that is unset, which can happen when
|
2019-02-06 19:11:36 +01:00
|
|
|
capture group number \fIn+1\fP matches some part of the subject, but group
|
|
|
|
\fIn\fP has not been used at all, it returns an empty string. This can be
|
|
|
|
distinguished from a genuine zero-length substring by inspecting the
|
2014-11-21 17:45:06 +01:00
|
|
|
appropriate offset in the ovector, which contain PCRE2_UNSET for unset
|
2014-12-13 18:43:26 +01:00
|
|
|
substrings, or by calling \fBpcre2_substring_length_bynumber()\fP.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
2014-11-14 19:41:20 +01:00
|
|
|
.\" HTML <a name="extractbyname"></a>
|
2014-09-19 09:43:39 +02:00
|
|
|
.SH "EXTRACTING CAPTURED SUBSTRINGS BY NAME"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_substring_number_from_name(const pcre2_code *\fIcode\fP,
|
|
|
|
.B " PCRE2_SPTR \fIname\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_substring_length_byname(pcre2_match_data *\fImatch_data\fP,
|
|
|
|
.B " PCRE2_SPTR \fIname\fP, PCRE2_SIZE *\fIlength\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_substring_copy_byname(pcre2_match_data *\fImatch_data\fP,
|
|
|
|
.B " PCRE2_SPTR \fIname\fP, PCRE2_UCHAR *\fIbuffer\fP, PCRE2_SIZE *\fIbufflen\fP);"
|
|
|
|
.sp
|
|
|
|
.B int pcre2_substring_get_byname(pcre2_match_data *\fImatch_data\fP,
|
|
|
|
.B " PCRE2_SPTR \fIname\fP, PCRE2_UCHAR **\fIbufferptr\fP, PCRE2_SIZE *\fIbufflen\fP);"
|
|
|
|
.sp
|
|
|
|
.B void pcre2_substring_free(PCRE2_UCHAR *\fIbuffer\fP);
|
|
|
|
.fi
|
|
|
|
.P
|
|
|
|
To extract a substring by name, you first have to find associated number.
|
|
|
|
For example, for this pattern:
|
|
|
|
.sp
|
|
|
|
(a+)b(?<xxx>\ed+)...
|
|
|
|
.sp
|
2019-02-06 19:11:36 +01:00
|
|
|
the number of the capture group called "xxx" is 2. If the name is known to be
|
2014-09-19 09:43:39 +02:00
|
|
|
unique (PCRE2_DUPNAMES was not set), you can find the number from the name by
|
|
|
|
calling \fBpcre2_substring_number_from_name()\fP. The first argument is the
|
|
|
|
compiled pattern, and the second is the name. The yield of the function is the
|
2019-02-06 19:11:36 +01:00
|
|
|
group number, PCRE2_ERROR_NOSUBSTRING if there is no group with that name, or
|
|
|
|
PCRE2_ERROR_NOUNIQUESUBSTRING if there is more than one group with that name.
|
|
|
|
Given the number, you can extract the substring directly from the ovector, or
|
|
|
|
use one of the "bynumber" functions described above.
|
2014-12-14 18:17:06 +01:00
|
|
|
.P
|
|
|
|
For convenience, there are also "byname" functions that correspond to the
|
|
|
|
"bynumber" functions, the only difference being that the second argument is a
|
|
|
|
name instead of a number. If PCRE2_DUPNAMES is set and there are duplicate
|
|
|
|
names, these functions scan all the groups with the given name, and return the
|
2019-02-06 19:11:36 +01:00
|
|
|
captured substring from the first named group that is set.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2014-12-19 10:55:25 +01:00
|
|
|
If there are no groups with the given name, PCRE2_ERROR_NOSUBSTRING is
|
|
|
|
returned. If all groups with the name have numbers that are greater than the
|
|
|
|
number of slots in the ovector, PCRE2_ERROR_UNAVAILABLE is returned. If there
|
|
|
|
is at least one group with a slot in the ovector, but no group is found to be
|
2014-12-14 18:17:06 +01:00
|
|
|
set, PCRE2_ERROR_UNSET is returned.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
\fBWarning:\fP If the pattern uses the (?| feature to set up multiple
|
2019-02-06 19:11:36 +01:00
|
|
|
capture groups with the same number, as described in the
|
|
|
|
.\" HTML <a href="pcre2pattern.html#dupgroupnumber">
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" </a>
|
2019-02-06 19:11:36 +01:00
|
|
|
section on duplicate group numbers
|
2014-09-19 09:43:39 +02:00
|
|
|
.\"
|
|
|
|
in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2pattern\fP
|
|
|
|
.\"
|
2019-02-06 19:11:36 +01:00
|
|
|
page, you cannot use names to distinguish the different capture groups, because
|
2014-09-19 09:43:39 +02:00
|
|
|
names are not included in the compiled code. The matching process uses only
|
2019-02-06 19:11:36 +01:00
|
|
|
numbers. For this reason, the use of different names for groups with the
|
2014-09-19 09:43:39 +02:00
|
|
|
same number causes an error at compile time.
|
|
|
|
.
|
|
|
|
.
|
2018-09-18 18:31:30 +02:00
|
|
|
.\" HTML <a name="substitutions"></a>
|
2014-11-11 17:51:07 +01:00
|
|
|
.SH "CREATING A NEW STRING WITH SUBSTITUTIONS"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_substitute(const pcre2_code *\fIcode\fP, PCRE2_SPTR \fIsubject\fP,
|
|
|
|
.B " PCRE2_SIZE \fIlength\fP, PCRE2_SIZE \fIstartoffset\fP,"
|
|
|
|
.B " uint32_t \fIoptions\fP, pcre2_match_data *\fImatch_data\fP,"
|
2015-10-07 19:32:48 +02:00
|
|
|
.B " pcre2_match_context *\fImcontext\fP, PCRE2_SPTR \fIreplacement\fP,"
|
2018-09-18 18:31:30 +02:00
|
|
|
.B " PCRE2_SIZE \fIrlength\fP, PCRE2_UCHAR *\fIoutputbuffer\fP,"
|
2014-11-11 17:51:07 +01:00
|
|
|
.B " PCRE2_SIZE *\fIoutlengthptr\fP);"
|
|
|
|
.fi
|
2015-10-07 19:32:48 +02:00
|
|
|
.P
|
2019-12-27 14:35:17 +01:00
|
|
|
This function optionally calls \fBpcre2_match()\fP and then makes a copy of the
|
|
|
|
subject string in \fIoutputbuffer\fP, replacing parts that were matched with
|
|
|
|
the \fIreplacement\fP string, whose length is supplied in \fBrlength\fP. This
|
2020-01-22 18:50:12 +01:00
|
|
|
can be given as PCRE2_ZERO_TERMINATED for a zero-terminated string. There is an
|
|
|
|
option (see PCRE2_SUBSTITUTE_REPLACEMENT_ONLY below) to return just the
|
|
|
|
replacement string(s). The default action is to perform just one replacement if
|
|
|
|
the pattern matches, but there is an option that requests multiple replacements
|
2020-02-16 18:46:40 +01:00
|
|
|
(see PCRE2_SUBSTITUTE_GLOBAL below).
|
2019-12-27 14:35:17 +01:00
|
|
|
.P
|
|
|
|
If successful, \fBpcre2_substitute()\fP returns the number of substitutions
|
|
|
|
that were carried out. This may be zero if no match was found, and is never
|
|
|
|
greater than one unless PCRE2_SUBSTITUTE_GLOBAL is set. A negative value is
|
2020-02-16 18:46:40 +01:00
|
|
|
returned if an error is detected.
|
2018-09-18 18:31:30 +02:00
|
|
|
.P
|
|
|
|
Matches in which a \eK item in a lookahead in the pattern causes the match to
|
|
|
|
end before it starts are not supported, and give rise to an error return. For
|
|
|
|
global replacements, matches in which \eK in a lookbehind causes the match to
|
|
|
|
start earlier than the point that was reached in the previous iteration are
|
|
|
|
also not supported.
|
2014-11-11 17:51:07 +01:00
|
|
|
.P
|
2015-10-07 19:32:48 +02:00
|
|
|
The first seven arguments of \fBpcre2_substitute()\fP are the same as for
|
|
|
|
\fBpcre2_match()\fP, except that the partial matching options are not
|
|
|
|
permitted, and \fImatch_data\fP may be passed as NULL, in which case a match
|
|
|
|
data block is obtained and freed within this function, using memory management
|
|
|
|
functions from the match context, if provided, or else those that were used to
|
|
|
|
allocate memory for the compiled code.
|
|
|
|
.P
|
2020-02-16 18:46:40 +01:00
|
|
|
If \fImatch_data\fP is not NULL and PCRE2_SUBSTITUTE_MATCHED is not set, the
|
|
|
|
provided block is used for all calls to \fBpcre2_match()\fP, and its contents
|
|
|
|
afterwards are the result of the final call. For global changes, this will
|
|
|
|
always be a no-match error. The contents of the ovector within the match data
|
|
|
|
block may or may not have been changed.
|
2018-09-07 17:56:36 +02:00
|
|
|
.P
|
2019-12-27 14:35:17 +01:00
|
|
|
As well as the usual options for \fBpcre2_match()\fP, a number of additional
|
|
|
|
options can be set in the \fIoptions\fP argument of \fBpcre2_substitute()\fP.
|
|
|
|
One such option is PCRE2_SUBSTITUTE_MATCHED. When this is set, an external
|
|
|
|
\fImatch_data\fP block must be provided, and it must have been used for an
|
|
|
|
external call to \fBpcre2_match()\fP. The data in the \fImatch_data\fP block
|
|
|
|
(return code, offset vector) is used for the first substitution instead of
|
|
|
|
calling \fBpcre2_match()\fP from within \fBpcre2_substitute()\fP. This allows
|
|
|
|
an application to check for a match before choosing to substitute, without
|
|
|
|
having to repeat the match.
|
|
|
|
.P
|
2020-02-16 18:46:40 +01:00
|
|
|
The contents of the externally supplied match data block are not changed when
|
|
|
|
PCRE2_SUBSTITUTE_MATCHED is set. If PCRE2_SUBSTITUTE_GLOBAL is also set,
|
|
|
|
\fBpcre2_match()\fP is called after the first substitution to check for further
|
|
|
|
matches, but this is done using an internally obtained match data block, thus
|
|
|
|
always leaving the external block unchanged.
|
|
|
|
.P
|
|
|
|
The \fIcode\fP argument is not used for matching before the first substitution
|
|
|
|
when PCRE2_SUBSTITUTE_MATCHED is set, but it must be provided, even when
|
|
|
|
PCRE2_SUBSTITUTE_GLOBAL is not set, because it contains information such as the
|
|
|
|
UTF setting and the number of capturing parentheses in the pattern.
|
|
|
|
.P
|
|
|
|
The default action of \fBpcre2_substitute()\fP is to return a copy of the
|
|
|
|
subject string with matched substrings replaced. However, if
|
|
|
|
PCRE2_SUBSTITUTE_REPLACEMENT_ONLY is set, only the replacement substrings are
|
|
|
|
returned. In the global case, multiple replacements are concatenated in the
|
|
|
|
output buffer. Substitution callouts (see
|
2020-01-22 18:50:12 +01:00
|
|
|
.\" HTML <a href="#subcallouts">
|
|
|
|
.\" </a>
|
|
|
|
below)
|
|
|
|
.\"
|
|
|
|
can be used to separate them if necessary.
|
2019-12-27 14:35:17 +01:00
|
|
|
.P
|
|
|
|
The \fIoutlengthptr\fP argument of \fBpcre2_substitute()\fP must point to a
|
|
|
|
variable that contains the length, in code units, of the output buffer. If the
|
2020-02-16 18:46:40 +01:00
|
|
|
function is successful, the value is updated to contain the length in code
|
|
|
|
units of the new string, excluding the trailing zero that is automatically
|
|
|
|
added.
|
2015-12-12 19:45:40 +01:00
|
|
|
.P
|
|
|
|
If the function is not successful, the value set via \fIoutlengthptr\fP depends
|
|
|
|
on the type of error. For syntax errors in the replacement string, the value is
|
|
|
|
the offset in the replacement string where the error was detected. For other
|
|
|
|
errors, the value is PCRE2_UNSET by default. This includes the case of the
|
2020-02-16 18:46:40 +01:00
|
|
|
output buffer being too small, unless PCRE2_SUBSTITUTE_OVERFLOW_LENGTH is set.
|
|
|
|
.P
|
|
|
|
PCRE2_SUBSTITUTE_OVERFLOW_LENGTH changes what happens when the output buffer is
|
|
|
|
too small. The default action is to return PCRE2_ERROR_NOMEMORY immediately. If
|
|
|
|
this option is set, however, \fBpcre2_substitute()\fP continues to go through
|
|
|
|
the motions of matching and substituting (without, of course, writing anything)
|
|
|
|
in order to compute the size of buffer that is needed. This value is passed
|
|
|
|
back via the \fIoutlengthptr\fP variable, with the result of the function still
|
|
|
|
being PCRE2_ERROR_NOMEMORY.
|
|
|
|
.P
|
|
|
|
Passing a buffer size of zero is a permitted way of finding out how much memory
|
|
|
|
is needed for given substitution. However, this does mean that the entire
|
|
|
|
operation is carried out twice. Depending on the application, it may be more
|
|
|
|
efficient to allocate a large buffer and free the excess afterwards, instead of
|
|
|
|
using PCRE2_SUBSTITUTE_OVERFLOW_LENGTH.
|
|
|
|
.P
|
|
|
|
The replacement string, which is interpreted as a UTF string in UTF mode, is
|
|
|
|
checked for UTF validity unless PCRE2_NO_UTF_CHECK is set. An invalid UTF
|
|
|
|
replacement string causes an immediate return with the relevant UTF error code.
|
|
|
|
.P
|
|
|
|
If PCRE2_SUBSTITUTE_LITERAL is set, the replacement string is not interpreted
|
|
|
|
in any way. By default, however, a dollar character is an escape character that
|
|
|
|
can specify the insertion of characters from capture groups and names from
|
|
|
|
(*MARK) or other control verbs in the pattern. The following forms are always
|
|
|
|
recognized:
|
2014-11-11 17:51:07 +01:00
|
|
|
.sp
|
2015-08-29 19:13:09 +02:00
|
|
|
$$ insert a dollar character
|
|
|
|
$<n> or ${<n>} insert the contents of group <n>
|
2018-09-18 18:31:30 +02:00
|
|
|
$*MARK or ${*MARK} insert a control verb name
|
2014-11-11 17:51:07 +01:00
|
|
|
.sp
|
|
|
|
Either a group number or a group name can be given for <n>. Curly brackets are
|
|
|
|
required only if the following character would be interpreted as part of the
|
|
|
|
number or name. The number may be zero to include the entire matched string.
|
2014-11-21 17:45:06 +01:00
|
|
|
For example, if the pattern a(b)c is matched with "=abc=" and the replacement
|
2015-10-07 19:32:48 +02:00
|
|
|
string "+$1$0$1+", the result is "=+babcb+=".
|
2014-11-11 17:51:07 +01:00
|
|
|
.P
|
2018-11-27 17:41:20 +01:00
|
|
|
$*MARK inserts the name from the last encountered backtracking control verb on
|
|
|
|
the matching path that has a name. (*MARK) must always include a name, but the
|
|
|
|
other verbs need not. For example, in the case of (*MARK:A)(*PRUNE) the name
|
|
|
|
inserted is "A", but for (*MARK:A)(*PRUNE:B) the relevant name is "B". This
|
|
|
|
facility can be used to perform simple simultaneous substitutions, as this
|
|
|
|
\fBpcre2test\fP example shows:
|
2015-08-29 19:13:09 +02:00
|
|
|
.sp
|
2017-10-13 18:26:24 +02:00
|
|
|
/(*MARK:pear)apple|(*MARK:orange)lemon/g,replace=${*MARK}
|
2015-08-29 19:13:09 +02:00
|
|
|
apple lemon
|
|
|
|
2: pear orange
|
2015-10-07 19:32:48 +02:00
|
|
|
.sp
|
2015-12-04 19:39:08 +01:00
|
|
|
PCRE2_SUBSTITUTE_GLOBAL causes the function to iterate over the subject string,
|
2017-10-23 18:57:22 +02:00
|
|
|
replacing every matching substring. If this option is not set, only the first
|
|
|
|
matching substring is replaced. The search for matches takes place in the
|
2018-01-13 17:53:02 +01:00
|
|
|
original subject string (that is, previous replacements do not affect it).
|
2017-10-23 18:57:22 +02:00
|
|
|
Iteration is implemented by advancing the \fIstartoffset\fP value for each
|
|
|
|
search, which is always passed the entire subject string. If an offset limit is
|
|
|
|
set in the match context, searching stops when that limit is reached.
|
|
|
|
.P
|
|
|
|
You can restrict the effect of a global substitution to a portion of the
|
|
|
|
subject string by setting either or both of \fIstartoffset\fP and an offset
|
2020-04-24 18:05:36 +02:00
|
|
|
limit. Here is a \fBpcre2test\fP example:
|
2017-10-23 18:57:22 +02:00
|
|
|
.sp
|
|
|
|
/B/g,replace=!,use_offset_limit
|
2017-12-22 16:56:27 +01:00
|
|
|
ABC ABC ABC ABC\e=offset=3,offset_limit=12
|
2017-10-23 18:57:22 +02:00
|
|
|
2: ABC A!C A!C ABC
|
|
|
|
.sp
|
|
|
|
When continuing with global substitutions after matching a substring with zero
|
|
|
|
length, an attempt to find a non-empty match at the same offset is performed.
|
|
|
|
If this is not successful, the offset is advanced by one character except when
|
|
|
|
CRLF is a valid newline sequence and the next two characters are CR, LF. In
|
|
|
|
this case, the offset is advanced by two characters.
|
2015-12-04 19:39:08 +01:00
|
|
|
.P
|
2019-02-06 19:11:36 +01:00
|
|
|
PCRE2_SUBSTITUTE_UNKNOWN_UNSET causes references to capture groups that do
|
2015-12-17 19:44:06 +01:00
|
|
|
not appear in the pattern to be treated as unset groups. This option should be
|
|
|
|
used with care, because it means that a typo in a group name or number no
|
2015-12-12 19:45:40 +01:00
|
|
|
longer causes the PCRE2_ERROR_NOSUBSTRING error.
|
|
|
|
.P
|
2019-02-06 19:11:36 +01:00
|
|
|
PCRE2_SUBSTITUTE_UNSET_EMPTY causes unset capture groups (including unknown
|
2015-12-12 19:45:40 +01:00
|
|
|
groups when PCRE2_SUBSTITUTE_UNKNOWN_UNSET is set) to be treated as empty
|
|
|
|
strings when inserted as described above. If this option is not set, an attempt
|
|
|
|
to insert an unset group causes the PCRE2_ERROR_UNSET error. This option does
|
|
|
|
not influence the extended substitution syntax described below.
|
2015-12-04 19:39:08 +01:00
|
|
|
.P
|
|
|
|
PCRE2_SUBSTITUTE_EXTENDED causes extra processing to be applied to the
|
|
|
|
replacement string. Without this option, only the dollar character is special,
|
|
|
|
and only the group insertion forms listed above are valid. When
|
|
|
|
PCRE2_SUBSTITUTE_EXTENDED is set, two things change:
|
2015-10-07 19:32:48 +02:00
|
|
|
.P
|
|
|
|
Firstly, backslash in a replacement string is interpreted as an escape
|
|
|
|
character. The usual forms such as \en or \ex{ddd} can be used to specify
|
|
|
|
particular character codes, and backslash followed by any non-alphanumeric
|
|
|
|
character quotes that character. Extended quoting can be coded using \eQ...\eE,
|
|
|
|
exactly as in pattern strings.
|
|
|
|
.P
|
|
|
|
There are also four escape sequences for forcing the case of inserted letters.
|
|
|
|
The insertion mechanism has three states: no case forcing, force upper case,
|
|
|
|
and force lower case. The escape sequences change the current state: \eU and
|
|
|
|
\eL change to upper or lower case forcing, respectively, and \eE (when not
|
|
|
|
terminating a \eQ quoted sequence) reverts to no case forcing. The sequences
|
|
|
|
\eu and \el force the next character (if it is a letter) to upper or lower
|
|
|
|
case, respectively, and then the state automatically reverts to no case
|
|
|
|
forcing. Case forcing applies to all inserted characters, including those from
|
2020-04-15 18:34:36 +02:00
|
|
|
capture groups and letters within \eQ...\eE quoted sequences. If either
|
|
|
|
PCRE2_UTF or PCRE2_UCP was set when the pattern was compiled, Unicode
|
2020-02-24 17:35:15 +01:00
|
|
|
properties are used for case forcing characters whose code points are greater
|
|
|
|
than 127.
|
2015-10-07 19:32:48 +02:00
|
|
|
.P
|
|
|
|
Note that case forcing sequences such as \eU...\eE do not nest. For example,
|
|
|
|
the result of processing "\eUaa\eLBB\eEcc\eE" is "AAbbcc"; the final \eE has no
|
2019-03-04 19:07:04 +01:00
|
|
|
effect. Note also that the PCRE2_ALT_BSUX and PCRE2_EXTRA_ALT_BSUX options do
|
2019-09-26 18:10:30 +02:00
|
|
|
not apply to replacement strings.
|
2015-10-07 19:32:48 +02:00
|
|
|
.P
|
|
|
|
The second effect of setting PCRE2_SUBSTITUTE_EXTENDED is to add more
|
2019-02-06 19:11:36 +01:00
|
|
|
flexibility to capture group substitution. The syntax is similar to that used
|
|
|
|
by Bash:
|
2015-10-07 19:32:48 +02:00
|
|
|
.sp
|
|
|
|
${<n>:-<string>}
|
|
|
|
${<n>:+<string1>:<string2>}
|
|
|
|
.sp
|
|
|
|
As before, <n> may be a group number or a name. The first form specifies a
|
|
|
|
default value. If group <n> is set, its value is inserted; if not, <string> is
|
|
|
|
expanded and the result inserted. The second form specifies strings that are
|
|
|
|
expanded and inserted when group <n> is set or unset, respectively. The first
|
|
|
|
form is just a convenient shorthand for
|
|
|
|
.sp
|
|
|
|
${<n>:+${<n>}:<string>}
|
|
|
|
.sp
|
|
|
|
Backslash can be used to escape colons and closing curly brackets in the
|
|
|
|
replacement strings. A change of the case forcing state within a replacement
|
|
|
|
string remains in force afterwards, as shown in this \fBpcre2test\fP example:
|
|
|
|
.sp
|
|
|
|
/(some)?(body)/substitute_extended,replace=${1:+\eU:\eL}HeLLo
|
|
|
|
body
|
|
|
|
1: hello
|
|
|
|
somebody
|
|
|
|
1: HELLO
|
|
|
|
.sp
|
2015-12-17 19:44:06 +01:00
|
|
|
The PCRE2_SUBSTITUTE_UNSET_EMPTY option does not affect these extended
|
|
|
|
substitutions. However, PCRE2_SUBSTITUTE_UNKNOWN_UNSET does cause unknown
|
2015-12-12 19:45:40 +01:00
|
|
|
groups in the extended syntax forms to be treated as unset.
|
2015-12-04 19:39:08 +01:00
|
|
|
.P
|
2019-12-27 14:35:17 +01:00
|
|
|
If PCRE2_SUBSTITUTE_LITERAL is set, PCRE2_SUBSTITUTE_UNKNOWN_UNSET,
|
|
|
|
PCRE2_SUBSTITUTE_UNSET_EMPTY, and PCRE2_SUBSTITUTE_EXTENDED are irrelevant and
|
|
|
|
are ignored.
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.SS "Substitution errors"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
In the event of an error, \fBpcre2_substitute()\fP returns a negative error
|
|
|
|
code. Except for PCRE2_ERROR_NOMATCH (which is never returned), errors from
|
|
|
|
\fBpcre2_match()\fP are passed straight back.
|
2015-12-12 19:45:40 +01:00
|
|
|
.P
|
|
|
|
PCRE2_ERROR_NOSUBSTRING is returned for a non-existent substring insertion,
|
|
|
|
unless PCRE2_SUBSTITUTE_UNKNOWN_UNSET is set.
|
|
|
|
.P
|
|
|
|
PCRE2_ERROR_UNSET is returned for an unset substring insertion (including an
|
|
|
|
unknown substring when PCRE2_SUBSTITUTE_UNKNOWN_UNSET is set) when the simple
|
|
|
|
(non-extended) syntax is used and PCRE2_SUBSTITUTE_UNSET_EMPTY is not set.
|
|
|
|
.P
|
|
|
|
PCRE2_ERROR_NOMEMORY is returned if the output buffer is not big enough. If the
|
|
|
|
PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option is set, the size of buffer that is
|
2015-12-17 19:44:06 +01:00
|
|
|
needed is returned via \fIoutlengthptr\fP. Note that this does not happen by
|
2015-12-12 19:45:40 +01:00
|
|
|
default.
|
|
|
|
.P
|
2019-12-27 14:35:17 +01:00
|
|
|
PCRE2_ERROR_NULL is returned if PCRE2_SUBSTITUTE_MATCHED is set but the
|
|
|
|
\fImatch_data\fP argument is NULL.
|
|
|
|
.P
|
2015-12-12 19:45:40 +01:00
|
|
|
PCRE2_ERROR_BADREPLACEMENT is used for miscellaneous syntax errors in the
|
|
|
|
replacement string, with more particular errors being PCRE2_ERROR_BADREPESCAPE
|
2017-09-25 17:05:29 +02:00
|
|
|
(invalid escape sequence), PCRE2_ERROR_REPMISSINGBRACE (closing curly bracket
|
|
|
|
not found), PCRE2_ERROR_BADSUBSTITUTION (syntax error in extended group
|
|
|
|
substitution), and PCRE2_ERROR_BADSUBSPATTERN (the pattern match ended before
|
2018-08-13 13:57:09 +02:00
|
|
|
it started or the match started earlier than the current position in the
|
2018-06-22 18:29:56 +02:00
|
|
|
subject, which can happen if \eK is used in an assertion).
|
2015-12-12 19:45:40 +01:00
|
|
|
.P
|
|
|
|
As for all PCRE2 errors, a text message that describes the error can be
|
2016-06-17 13:30:27 +02:00
|
|
|
obtained by calling the \fBpcre2_get_error_message()\fP function (see
|
|
|
|
"Obtaining a textual error message"
|
|
|
|
.\" HTML <a href="#geterrormessage">
|
|
|
|
.\" </a>
|
|
|
|
above).
|
|
|
|
.\"
|
2014-11-11 17:51:07 +01:00
|
|
|
.
|
|
|
|
.
|
2020-01-22 18:50:12 +01:00
|
|
|
.\" HTML <a name="subcallouts"></a>
|
2018-09-18 18:31:30 +02:00
|
|
|
.SS "Substitution callouts"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_set_substitute_callout(pcre2_match_context *\fImcontext\fP,
|
2018-11-12 17:02:01 +01:00
|
|
|
.B " int (*\fIcallout_function\fP)(pcre2_substitute_callout_block *, void *),"
|
2018-09-18 18:31:30 +02:00
|
|
|
.B " void *\fIcallout_data\fP);"
|
|
|
|
.fi
|
|
|
|
.sp
|
|
|
|
The \fBpcre2_set_substitution_callout()\fP function can be used to specify a
|
|
|
|
callout function for \fBpcre2_substitute()\fP. This information is passed in
|
2019-03-04 19:07:04 +01:00
|
|
|
a match context. The callout function is called after each substitution has
|
|
|
|
been processed, but it can cause the replacement not to happen. The callout
|
2018-11-12 17:02:01 +01:00
|
|
|
function is not called for simulated substitutions that happen as a result of
|
|
|
|
the PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option.
|
2018-09-18 18:31:30 +02:00
|
|
|
.P
|
|
|
|
The first argument of the callout function is a pointer to a substitute callout
|
|
|
|
block structure, which contains the following fields, not necessarily in this
|
|
|
|
order:
|
|
|
|
.sp
|
|
|
|
uint32_t \fIversion\fP;
|
2019-03-04 19:07:04 +01:00
|
|
|
uint32_t \fIsubscount\fP;
|
2018-11-12 17:02:01 +01:00
|
|
|
PCRE2_SPTR \fIinput\fP;
|
2019-03-04 19:07:04 +01:00
|
|
|
PCRE2_SPTR \fIoutput\fP;
|
|
|
|
PCRE2_SIZE \fI*ovector\fP;
|
2018-11-12 17:02:01 +01:00
|
|
|
uint32_t \fIoveccount\fP;
|
2018-09-18 18:31:30 +02:00
|
|
|
PCRE2_SIZE \fIoutput_offsets[2]\fP;
|
|
|
|
.sp
|
|
|
|
The \fIversion\fP field contains the version number of the block format. The
|
|
|
|
current version is 0. The version number will increase in future if more fields
|
|
|
|
are added, but the intention is never to remove any of the existing fields.
|
|
|
|
.P
|
2018-11-12 17:02:01 +01:00
|
|
|
The \fIsubscount\fP field is the number of the current match. It is 1 for the
|
|
|
|
first callout, 2 for the second, and so on. The \fIinput\fP and \fIoutput\fP
|
|
|
|
pointers are copies of the values passed to \fBpcre2_substitute()\fP.
|
|
|
|
.P
|
2019-03-04 19:07:04 +01:00
|
|
|
The \fIovector\fP field points to the ovector, which contains the result of the
|
|
|
|
most recent match. The \fIoveccount\fP field contains the number of pairs that
|
|
|
|
are set in the ovector, and is always greater than zero.
|
2018-11-12 17:02:01 +01:00
|
|
|
.P
|
|
|
|
The \fIoutput_offsets\fP vector contains the offsets of the replacement in the
|
|
|
|
output string. This has already been processed for dollar and (if requested)
|
|
|
|
backslash substitutions as described above.
|
2018-09-18 18:31:30 +02:00
|
|
|
.P
|
|
|
|
The second argument of the callout function is the value passed as
|
2018-11-12 17:02:01 +01:00
|
|
|
\fIcallout_data\fP when the function was registered. The value returned by the
|
|
|
|
callout function is interpreted as follows:
|
|
|
|
.P
|
|
|
|
If the value is zero, the replacement is accepted, and, if
|
|
|
|
PCRE2_SUBSTITUTE_GLOBAL is set, processing continues with a search for the next
|
|
|
|
match. If the value is not zero, the current replacement is not accepted. If
|
|
|
|
the value is greater than zero, processing continues when
|
|
|
|
PCRE2_SUBSTITUTE_GLOBAL is set. Otherwise (the value is less than zero or
|
|
|
|
PCRE2_SUBSTITUTE_GLOBAL is not set), the the rest of the input is copied to the
|
|
|
|
output and the call to \fBpcre2_substitute()\fP exits, returning the number of
|
|
|
|
matches so far.
|
2018-09-18 18:31:30 +02:00
|
|
|
.
|
|
|
|
.
|
2019-02-06 19:11:36 +01:00
|
|
|
.SH "DUPLICATE CAPTURE GROUP NAMES"
|
2014-09-19 09:43:39 +02:00
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_substring_nametable_scan(const pcre2_code *\fIcode\fP,
|
|
|
|
.B " PCRE2_SPTR \fIname\fP, PCRE2_SPTR *\fIfirst\fP, PCRE2_SPTR *\fIlast\fP);"
|
|
|
|
.fi
|
|
|
|
.P
|
2019-02-06 19:11:36 +01:00
|
|
|
When a pattern is compiled with the PCRE2_DUPNAMES option, names for capture
|
|
|
|
groups are not required to be unique. Duplicate names are always allowed for
|
|
|
|
groups with the same number, created by using the (?| feature. Indeed, if such
|
|
|
|
groups are named, they are required to use the same names.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
2019-02-06 19:11:36 +01:00
|
|
|
Normally, patterns that use duplicate names are such that in any one match,
|
|
|
|
only one of each set of identically-named groups participates. An example is
|
|
|
|
shown in the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2pattern\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
|
|
|
.P
|
|
|
|
When duplicates are present, \fBpcre2_substring_copy_byname()\fP and
|
|
|
|
\fBpcre2_substring_get_byname()\fP return the first substring corresponding to
|
2014-12-13 18:43:26 +01:00
|
|
|
the given name that is set. Only if none are set is PCRE2_ERROR_UNSET is
|
|
|
|
returned. The \fBpcre2_substring_number_from_name()\fP function returns the
|
|
|
|
error PCRE2_ERROR_NOUNIQUESUBSTRING when there are duplicate names.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
If you want to get full details of all captured substrings for a given name,
|
|
|
|
you must use the \fBpcre2_substring_nametable_scan()\fP function. The first
|
|
|
|
argument is the compiled pattern, and the second is the name. If the third and
|
2014-11-21 17:45:06 +01:00
|
|
|
fourth arguments are NULL, the function returns a group number for a unique
|
|
|
|
name, or PCRE2_ERROR_NOUNIQUESUBSTRING otherwise.
|
|
|
|
.P
|
|
|
|
When the third and fourth arguments are not NULL, they must be pointers to
|
2014-09-19 09:43:39 +02:00
|
|
|
variables that are updated by the function. After it has run, they point to the
|
|
|
|
first and last entries in the name-to-number table for the given name, and the
|
2014-11-21 17:45:06 +01:00
|
|
|
function returns the length of each entry in code units. In both cases,
|
2014-09-19 09:43:39 +02:00
|
|
|
PCRE2_ERROR_NOSUBSTRING is returned if there are no entries for the given name.
|
|
|
|
.P
|
2015-12-17 19:44:06 +01:00
|
|
|
The format of the name table is described
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HTML <a href="#infoaboutpattern">
|
|
|
|
.\" </a>
|
2015-12-17 19:44:06 +01:00
|
|
|
above
|
2014-09-19 09:43:39 +02:00
|
|
|
.\"
|
2015-12-17 19:44:06 +01:00
|
|
|
in the section entitled \fIInformation about a pattern\fP. Given all the
|
|
|
|
relevant entries for the name, you can extract each of their numbers, and hence
|
|
|
|
the captured data.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
2014-11-21 17:45:06 +01:00
|
|
|
.SH "FINDING ALL POSSIBLE MATCHES AT ONE POSITION"
|
2014-09-19 09:43:39 +02:00
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
The traditional matching function uses a similar algorithm to Perl, which stops
|
2014-11-21 17:45:06 +01:00
|
|
|
when it finds the first match at a given point in the subject. If you want to
|
|
|
|
find all possible matches, or the longest possible match at a given position,
|
|
|
|
consider using the alternative matching function (see below) instead. If you
|
|
|
|
cannot use the alternative function, you can kludge it up by making use of the
|
|
|
|
callout facility, which is described in the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2callout\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
|
|
|
.P
|
|
|
|
What you have to do is to insert a callout right at the end of the pattern.
|
|
|
|
When your callout function is called, extract and save the current matched
|
|
|
|
substring. Then return 1, which forces \fBpcre2_match()\fP to backtrack and try
|
|
|
|
other alternatives. Ultimately, when it runs out of matches,
|
|
|
|
\fBpcre2_match()\fP will yield PCRE2_ERROR_NOMATCH.
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.\" HTML <a name="dfamatch"></a>
|
|
|
|
.SH "MATCHING A PATTERN: THE ALTERNATIVE FUNCTION"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
.B int pcre2_dfa_match(const pcre2_code *\fIcode\fP, PCRE2_SPTR \fIsubject\fP,
|
|
|
|
.B " PCRE2_SIZE \fIlength\fP, PCRE2_SIZE \fIstartoffset\fP,"
|
|
|
|
.B " uint32_t \fIoptions\fP, pcre2_match_data *\fImatch_data\fP,"
|
|
|
|
.B " pcre2_match_context *\fImcontext\fP,"
|
|
|
|
.B " int *\fIworkspace\fP, PCRE2_SIZE \fIwscount\fP);"
|
|
|
|
.fi
|
|
|
|
.P
|
|
|
|
The function \fBpcre2_dfa_match()\fP is called to match a subject string
|
|
|
|
against a compiled pattern, using a matching algorithm that scans the subject
|
2017-03-28 18:34:29 +02:00
|
|
|
string just once (not counting lookaround assertions), and does not backtrack.
|
|
|
|
This has different characteristics to the normal algorithm, and is not
|
|
|
|
compatible with Perl. Some of the features of PCRE2 patterns are not supported.
|
|
|
|
Nevertheless, there are times when this kind of matching can be useful. For a
|
|
|
|
discussion of the two matching algorithms, and a list of features that
|
|
|
|
\fBpcre2_dfa_match()\fP does not support, see the
|
2014-09-19 09:43:39 +02:00
|
|
|
.\" HREF
|
|
|
|
\fBpcre2matching\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
|
|
|
.P
|
|
|
|
The arguments for the \fBpcre2_dfa_match()\fP function are the same as for
|
|
|
|
\fBpcre2_match()\fP, plus two extras. The ovector within the match data block
|
|
|
|
is used in a different way, and this is described below. The other common
|
|
|
|
arguments are used in the same way as for \fBpcre2_match()\fP, so their
|
|
|
|
description is not repeated here.
|
|
|
|
.P
|
|
|
|
The two additional arguments provide workspace for the function. The workspace
|
|
|
|
vector should contain at least 20 elements. It is used for keeping track of
|
|
|
|
multiple paths through the pattern tree. More workspace is needed for patterns
|
|
|
|
and subjects where there are a lot of potential matches.
|
|
|
|
.P
|
|
|
|
Here is an example of a simple call to \fBpcre2_dfa_match()\fP:
|
|
|
|
.sp
|
|
|
|
int wspace[20];
|
|
|
|
pcre2_match_data *md = pcre2_match_data_create(4, NULL);
|
|
|
|
int rc = pcre2_dfa_match(
|
|
|
|
re, /* result of pcre2_compile() */
|
|
|
|
"some string", /* the subject string */
|
|
|
|
11, /* the length of the subject string */
|
|
|
|
0, /* start at offset 0 in the subject */
|
|
|
|
0, /* default options */
|
2017-11-14 16:32:53 +01:00
|
|
|
md, /* the match data block */
|
2014-09-19 09:43:39 +02:00
|
|
|
NULL, /* a match context; NULL means use defaults */
|
|
|
|
wspace, /* working space vector */
|
|
|
|
20); /* number of elements (NOT size in bytes) */
|
|
|
|
.
|
|
|
|
.SS "Option bits for \fBpcre_dfa_match()\fP"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
The unused bits of the \fIoptions\fP argument for \fBpcre2_dfa_match()\fP must
|
2018-10-17 10:33:38 +02:00
|
|
|
be zero. The only bits that may be set are PCRE2_ANCHORED,
|
|
|
|
PCRE2_COPY_MATCHED_SUBJECT, PCRE2_ENDANCHORED, PCRE2_NOTBOL, PCRE2_NOTEOL,
|
|
|
|
PCRE2_NOTEMPTY, PCRE2_NOTEMPTY_ATSTART, PCRE2_NO_UTF_CHECK, PCRE2_PARTIAL_HARD,
|
|
|
|
PCRE2_PARTIAL_SOFT, PCRE2_DFA_SHORTEST, and PCRE2_DFA_RESTART. All but the last
|
|
|
|
four of these are exactly the same as for \fBpcre2_match()\fP, so their
|
|
|
|
description is not repeated here.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_PARTIAL_HARD
|
|
|
|
PCRE2_PARTIAL_SOFT
|
|
|
|
.sp
|
|
|
|
These have the same general effect as they do for \fBpcre2_match()\fP, but the
|
|
|
|
details are slightly different. When PCRE2_PARTIAL_HARD is set for
|
|
|
|
\fBpcre2_dfa_match()\fP, it returns PCRE2_ERROR_PARTIAL if the end of the
|
|
|
|
subject is reached and there is still at least one matching possibility that
|
|
|
|
requires additional characters. This happens even if some complete matches have
|
|
|
|
already been found. When PCRE2_PARTIAL_SOFT is set, the return code
|
|
|
|
PCRE2_ERROR_NOMATCH is converted into PCRE2_ERROR_PARTIAL if the end of the
|
|
|
|
subject is reached, there have been no complete matches, but there is still at
|
|
|
|
least one matching possibility. The portion of the string that was inspected
|
|
|
|
when the longest partial match was found is set as the first matching string in
|
|
|
|
both cases. There is a more detailed discussion of partial and multi-segment
|
|
|
|
matching, with examples, in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2partial\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
|
|
|
.sp
|
|
|
|
PCRE2_DFA_SHORTEST
|
|
|
|
.sp
|
|
|
|
Setting the PCRE2_DFA_SHORTEST option causes the matching algorithm to stop as
|
|
|
|
soon as it has found one match. Because of the way the alternative algorithm
|
|
|
|
works, this is necessarily the shortest possible match at the first possible
|
|
|
|
matching point in the subject string.
|
|
|
|
.sp
|
|
|
|
PCRE2_DFA_RESTART
|
|
|
|
.sp
|
|
|
|
When \fBpcre2_dfa_match()\fP returns a partial match, it is possible to call it
|
|
|
|
again, with additional subject characters, and have it continue with the same
|
|
|
|
match. The PCRE2_DFA_RESTART option requests this action; when it is set, the
|
|
|
|
\fIworkspace\fP and \fIwscount\fP options must reference the same vector as
|
|
|
|
before because data about the match so far is left in them after a partial
|
|
|
|
match. There is more discussion of this facility in the
|
|
|
|
.\" HREF
|
|
|
|
\fBpcre2partial\fP
|
|
|
|
.\"
|
|
|
|
documentation.
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.SS "Successful returns from \fBpcre2_dfa_match()\fP"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
When \fBpcre2_dfa_match()\fP succeeds, it may have matched more than one
|
|
|
|
substring in the subject. Note, however, that all the matches from one run of
|
|
|
|
the function start at the same point in the subject. The shorter matches are
|
|
|
|
all initial substrings of the longer matches. For example, if the pattern
|
|
|
|
.sp
|
|
|
|
<.*>
|
|
|
|
.sp
|
|
|
|
is matched against the string
|
|
|
|
.sp
|
|
|
|
This is <something> <something else> <something further> no more
|
|
|
|
.sp
|
|
|
|
the three matched strings are
|
|
|
|
.sp
|
|
|
|
<something> <something else> <something further>
|
2014-12-14 18:17:06 +01:00
|
|
|
<something> <something else>
|
|
|
|
<something>
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
On success, the yield of the function is a number greater than zero, which is
|
|
|
|
the number of matched substrings. The offsets of the substrings are returned in
|
2014-12-14 18:17:06 +01:00
|
|
|
the ovector, and can be extracted by number in the same way as for
|
2019-02-06 19:11:36 +01:00
|
|
|
\fBpcre2_match()\fP, but the numbers bear no relation to any capture groups
|
|
|
|
that may exist in the pattern, because DFA matching does not support capturing.
|
2014-12-14 18:17:06 +01:00
|
|
|
.P
|
|
|
|
Calls to the convenience functions that extract substrings by name
|
|
|
|
return the error PCRE2_ERROR_DFA_UFUNC (unsupported function) if used after a
|
|
|
|
DFA match. The convenience functions that extract substrings by number never
|
2018-04-27 18:48:35 +02:00
|
|
|
return PCRE2_ERROR_NOSUBSTRING.
|
2014-12-14 18:17:06 +01:00
|
|
|
.P
|
|
|
|
The matched strings are stored in the ovector in reverse order of length; that
|
|
|
|
is, the longest matching string is first. If there were too many matches to fit
|
|
|
|
into the ovector, the yield of the function is zero, and the vector is filled
|
|
|
|
with the longest matches.
|
2014-09-19 09:43:39 +02:00
|
|
|
.P
|
|
|
|
NOTE: PCRE2's "auto-possessification" optimization usually applies to character
|
|
|
|
repeats at the end of a pattern (as well as internally). For example, the
|
2014-11-21 17:45:06 +01:00
|
|
|
pattern "a\ed+" is compiled as if it were "a\ed++". For DFA matching, this
|
|
|
|
means that only one possible match is found. If you really do want multiple
|
2017-04-20 18:34:35 +02:00
|
|
|
matches in such cases, either use an ungreedy repeat such as "a\ed+?" or set
|
2014-11-21 17:45:06 +01:00
|
|
|
the PCRE2_NO_AUTO_POSSESS option when compiling.
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.SS "Error returns from \fBpcre2_dfa_match()\fP"
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
The \fBpcre2_dfa_match()\fP function returns a negative number when it fails.
|
|
|
|
Many of the errors are the same as for \fBpcre2_match()\fP, as described
|
|
|
|
.\" HTML <a href="#errorlist">
|
|
|
|
.\" </a>
|
|
|
|
above.
|
|
|
|
.\"
|
|
|
|
There are in addition the following errors that are specific to
|
|
|
|
\fBpcre2_dfa_match()\fP:
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_DFA_UITEM
|
|
|
|
.sp
|
|
|
|
This return is given if \fBpcre2_dfa_match()\fP encounters an item in the
|
2015-10-17 15:50:56 +02:00
|
|
|
pattern that it does not support, for instance, the use of \eC in a UTF mode or
|
2018-06-17 16:13:28 +02:00
|
|
|
a backreference.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_DFA_UCOND
|
|
|
|
.sp
|
|
|
|
This return is given if \fBpcre2_dfa_match()\fP encounters a condition item
|
2018-06-17 16:13:28 +02:00
|
|
|
that uses a backreference for the condition, or a test for recursion in a
|
2019-02-06 19:11:36 +01:00
|
|
|
specific capture group. These are not supported.
|
2019-05-24 19:15:48 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_DFA_UINVALID_UTF
|
|
|
|
.sp
|
|
|
|
This return is given if \fBpcre2_dfa_match()\fP is called for a pattern that
|
|
|
|
was compiled with PCRE2_MATCH_INVALID_UTF. This is not supported for DFA
|
|
|
|
matching.
|
2014-09-19 09:43:39 +02:00
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_DFA_WSSIZE
|
|
|
|
.sp
|
|
|
|
This return is given if \fBpcre2_dfa_match()\fP runs out of space in the
|
|
|
|
\fIworkspace\fP vector.
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_DFA_RECURSE
|
|
|
|
.sp
|
2019-02-06 19:11:36 +01:00
|
|
|
When a recursion or subroutine call is processed, the matching function calls
|
|
|
|
itself recursively, using private memory for the ovector and \fIworkspace\fP.
|
|
|
|
This error is given if the internal ovector is not large enough. This should be
|
2014-09-19 09:43:39 +02:00
|
|
|
extremely rare, as a vector of size 1000 is used.
|
|
|
|
.sp
|
|
|
|
PCRE2_ERROR_DFA_BADRESTART
|
|
|
|
.sp
|
2014-11-21 17:45:06 +01:00
|
|
|
When \fBpcre2_dfa_match()\fP is called with the \fBPCRE2_DFA_RESTART\fP option,
|
2014-09-19 09:43:39 +02:00
|
|
|
some plausibility checks are made on the contents of the workspace, which
|
|
|
|
should contain data about the previous partial match. If any of these checks
|
|
|
|
fail, this error is given.
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH "SEE ALSO"
|
|
|
|
.rs
|
|
|
|
.sp
|
2014-11-21 17:45:06 +01:00
|
|
|
\fBpcre2build\fP(3), \fBpcre2callout\fP(3), \fBpcre2demo(3)\fP,
|
2014-10-20 19:28:49 +02:00
|
|
|
\fBpcre2matching\fP(3), \fBpcre2partial\fP(3), \fBpcre2posix\fP(3),
|
2017-04-01 11:38:58 +02:00
|
|
|
\fBpcre2sample\fP(3), \fBpcre2unicode\fP(3).
|
2014-09-19 09:43:39 +02:00
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH AUTHOR
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
|
|
|
Philip Hazel
|
2021-08-28 17:25:59 +02:00
|
|
|
Retired from University Computing Service
|
2014-11-17 17:59:02 +01:00
|
|
|
Cambridge, England.
|
2014-09-19 09:43:39 +02:00
|
|
|
.fi
|
|
|
|
.
|
|
|
|
.
|
|
|
|
.SH REVISION
|
|
|
|
.rs
|
|
|
|
.sp
|
|
|
|
.nf
|
2021-08-28 17:25:59 +02:00
|
|
|
Last updated: 28 August 2021
|
|
|
|
Copyright (c) 1997-2021 University of Cambridge.
|
2014-09-19 09:43:39 +02:00
|
|
|
.fi
|