pcre2_pattern_info man page

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SYNOPSIS

#include <pcre2.h>

int pcre2_pattern_info(const pcre2 *code, uint32_t what, void *where);

DESCRIPTION

This function returns information about a compiled pattern. Its arguments are:

  code                      Compiled regular expression
  what                      What information is required
  where                     Where to put the information

If where is NULL, the function returns the amount of memory needed for the requested information, in bytes. The following information is available:

  PCRE2_INFO_ALLOPTIONS      Final options after compiling
  PCRE2_INFO_ARGOPTIONS      Options passed to pcre2_compile()
  PCRE2_INFO_BACKREFMAX      Number of highest back reference
  PCRE2_INFO_BSR             What \R matches
                               0 all Unicode line endings
                               1 CR, LF, or CRLF only
  PCRE2_INFO_CAPTURECOUNT    Number of capturing subpatterns
  PCRE2_INFO_FIRSTBITMAP     Bitmap of first code units, or NULL
  PCRE2_INFO_FIRSTCODEUNIT   First code unit when type is 1
  PCRE2_INFO_FIRSTCODETYPE   Type of start-of-match information
                               0 nothing set
                               1 first code unit is set
                               2 start of string or after newline
  PCRE2_INFO_HASCRORLF       Return 1 if explicit CR or LF matches
                               exist in the pattern
  PCRE2_INFO_JCHANGED        Return 1 if (?J) or (?-J) was used
  PCRE2_INFO_JITSIZE         Size of JIT compiled code, or 0
  PCRE2_INFO_LASTCODEUNIT    Last code unit when type is 1
  PCRE2_INFO_LASTCODETYPE    Type of must-be-present information
                               0 nothing set
                               1 code unit is set
  PCRE2_INFO_MATCHEMPTY      1 if the pattern can match an
                               empty string, 0 otherwise
  PCRE2_INFO_MATCHLIMIT      Match limit if set,
                               otherwise PCRE2_RROR_UNSET
  PCRE2_INFO_MAXLOOKBEHIND   Length (in characters) of the longest
                               lookbehind assertion
  PCRE2_INFO_MINLENGTH       Lower bound length of matching strings
  PCRE2_INFO_NAMEENTRYSIZE   Size of name table entries
  PCRE2_INFO_NAMECOUNT       Number of named subpatterns
  PCRE2_INFO_NAMETABLE       Pointer to name table
  PCRE2_CONFIG_NEWLINE       Code for the newline sequence:
                               1    for CR
                               2    for LF
                               3    for CRLF
                               4    for ANY
                               5    for ANYCRLF
  PCRE2_INFO_RECURSIONLIMIT  Recursion limit if set,
                               otherwise PCRE2_ERROR_UNSET
  PCRE2_INFO_SIZE            Size of compiled pattern

The where argument must point to an unsigned 32-bit integer (uint32_t variable), except for the following what values:

  PCRE2_INFO_FIRSTBITMAP     const uint8_t
  PCRE2_INFO_JITSIZE         size_t
  PCRE2_INFO_NAMETABLE       PCRE2_SPTR
  PCRE2_INFO_SIZE            size_t

The yield of the function is zero on success or:

  PCRE2_ERROR_NULL           the argument code is NULL
  PCRE2_ERROR_BADMAGIC       the "magic number" was not found
  PCRE2_ERROR_BADOPTION      the value of what is invalid
  PCRE2_ERROR_BADMODE        the pattern was compiled in the wrong mode
  PCRE2_ERROR_UNSET          the requested information is not set

There is a complete description of the PCRE2 native API in the pcre2api page and a description of the POSIX API in the pcre2posix page.

Return to the PCRE2 index page.