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Make pcre2test show actual pre-match consulted characters for a partial match, 

not the length of the longest lookbehind. Control this by "allusedtext".
This commit is contained in:
Philip.Hazel 2019-06-26 08:23:47 +00:00
parent d21f7daf9b
commit 434e3f7468
10 changed files with 483 additions and 350 deletions
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8
ChangeLog
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@ -71,6 +71,14 @@ lookbehind value. For example /(?<=a(?<=ba)c)/ previously set a maximum
lookbehind of 2, because that is the largest individual lookbehind. Now it sets lookbehind of 2, because that is the largest individual lookbehind. Now it sets
it to 3, because matching looks back 3 characters. it to 3, because matching looks back 3 characters.
14. For partial matches, pcre2test was always showing the maximum lookbehind
characters, flagged with "<", which is misleading when the lookbehind didn't
actually look behind the start (because it was later in the pattern). Showing
all consulted preceding characters for partial matches is now controlled by the
existing "allusedtext" modifier and, as for complete matches, this facility is
available only for non-JIT matching, because JIT does not maintain the first
and last consulted characters.
Version 10.33 16-April-2019 Version 10.33 16-April-2019
--------------------------- ---------------------------

27
doc/html/pcre2test.html
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@ -1252,22 +1252,27 @@ following line with a plus character following the capture number.
</P> </P>
<P> <P>
The <b>allusedtext</b> modifier requests that all the text that was consulted The <b>allusedtext</b> modifier requests that all the text that was consulted
during a successful pattern match by the interpreter should be shown. This during a successful pattern match by the interpreter should be shown, for both
feature is not supported for JIT matching, and if requested with JIT it is full and partial matches. This feature is not supported for JIT matching, and
ignored (with a warning message). Setting this modifier affects the output if if requested with JIT it is ignored (with a warning message). Setting this
there is a lookbehind at the start of a match, or a lookahead at the end, or if modifier affects the output if there is a lookbehind at the start of a match,
\K is used in the pattern. Characters that precede or follow the start and end or, for a complete match, a lookahead at the end, or if \K is used in the
of the actual match are indicated in the output by '&#60;' or '&#62;' characters pattern. Characters that precede or follow the start and end of the actual
underneath them. Here is an example: match are indicated in the output by '&#60;' or '&#62;' characters underneath them.
Here is an example:
<pre> <pre>
re&#62; /(?&#60;=pqr)abc(?=xyz)/ re&#62; /(?&#60;=pqr)abc(?=xyz)/
data&#62; 123pqrabcxyz456\=allusedtext data&#62; 123pqrabcxyz456\=allusedtext
0: pqrabcxyz 0: pqrabcxyz
&#60;&#60;&#60; &#62;&#62;&#62; &#60;&#60;&#60; &#62;&#62;&#62;
data&#62; 123pqrabcxy\=ph,allusedtext
Partial match: pqrabcxy
&#60;&#60;&#60;
</pre> </pre>
This shows that the matched string is "abc", with the preceding and following The first, complete match shows that the matched string is "abc", with the
strings "pqr" and "xyz" having been consulted during the match (when processing preceding and following strings "pqr" and "xyz" having been consulted during
the assertions). the match (when processing the assertions). The partial match can indicate only
the preceding string.
</P> </P>
<P> <P>
The <b>startchar</b> modifier requests that the starting character for the match The <b>startchar</b> modifier requests that the starting character for the match
@ -2081,7 +2086,7 @@ Cambridge, England.
</P> </P>
<br><a name="SEC21" href="#TOC1">REVISION</a><br> <br><a name="SEC21" href="#TOC1">REVISION</a><br>
<P> <P>
Last updated: 20 June 2019 Last updated: 26 June 2019
<br> <br>
Copyright &copy; 1997-2019 University of Cambridge. Copyright &copy; 1997-2019 University of Cambridge.
<br> <br>

29
doc/pcre2test.1
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@ -1,4 +1,4 @@
.TH PCRE2TEST 1 "20 June 2019" "PCRE 10.34" .TH PCRE2TEST 1 "26 June 2019" "PCRE 10.34"
.SH NAME .SH NAME
pcre2test - a program for testing Perl-compatible regular expressions. pcre2test - a program for testing Perl-compatible regular expressions.
.SH SYNOPSIS .SH SYNOPSIS
@ -1220,22 +1220,27 @@ well as the main matched substring. In each case the remainder is output on the
following line with a plus character following the capture number. following line with a plus character following the capture number.
.P .P
The \fBallusedtext\fP modifier requests that all the text that was consulted The \fBallusedtext\fP modifier requests that all the text that was consulted
during a successful pattern match by the interpreter should be shown. This during a successful pattern match by the interpreter should be shown, for both
feature is not supported for JIT matching, and if requested with JIT it is full and partial matches. This feature is not supported for JIT matching, and
ignored (with a warning message). Setting this modifier affects the output if if requested with JIT it is ignored (with a warning message). Setting this
there is a lookbehind at the start of a match, or a lookahead at the end, or if modifier affects the output if there is a lookbehind at the start of a match,
\eK is used in the pattern. Characters that precede or follow the start and end or, for a complete match, a lookahead at the end, or if \eK is used in the
of the actual match are indicated in the output by '<' or '>' characters pattern. Characters that precede or follow the start and end of the actual
underneath them. Here is an example: match are indicated in the output by '<' or '>' characters underneath them.
Here is an example:
.sp .sp
re> /(?<=pqr)abc(?=xyz)/ re> /(?<=pqr)abc(?=xyz)/
data> 123pqrabcxyz456\e=allusedtext data> 123pqrabcxyz456\e=allusedtext
0: pqrabcxyz 0: pqrabcxyz
<<< >>> <<< >>>
data> 123pqrabcxy\e=ph,allusedtext
Partial match: pqrabcxy
<<<
.sp .sp
This shows that the matched string is "abc", with the preceding and following The first, complete match shows that the matched string is "abc", with the
strings "pqr" and "xyz" having been consulted during the match (when processing preceding and following strings "pqr" and "xyz" having been consulted during
the assertions). the match (when processing the assertions). The partial match can indicate only
the preceding string.
.P .P
The \fBstartchar\fP modifier requests that the starting character for the match The \fBstartchar\fP modifier requests that the starting character for the match
be indicated, if it is different to the start of the matched string. The only be indicated, if it is different to the start of the matched string. The only
@ -2062,6 +2067,6 @@ Cambridge, England.
.rs .rs
.sp .sp
.nf .nf
Last updated: 20 June 2019 Last updated: 26 June 2019
Copyright (c) 1997-2019 University of Cambridge. Copyright (c) 1997-2019 University of Cambridge.
.fi .fi

512
doc/pcre2test.txt
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@ -1122,29 +1122,33 @@ SUBJECT MODIFIERS
capture number. capture number.
The allusedtext modifier requests that all the text that was consulted The allusedtext modifier requests that all the text that was consulted
during a successful pattern match by the interpreter should be shown. during a successful pattern match by the interpreter should be shown,
This feature is not supported for JIT matching, and if requested with for both full and partial matches. This feature is not supported for
JIT it is ignored (with a warning message). Setting this modifier af- JIT matching, and if requested with JIT it is ignored (with a warning
fects the output if there is a lookbehind at the start of a match, or a message). Setting this modifier affects the output if there is a look-
lookahead at the end, or if \K is used in the pattern. Characters that behind at the start of a match, or, for a complete match, a lookahead
precede or follow the start and end of the actual match are indicated at the end, or if \K is used in the pattern. Characters that precede or
in the output by '<' or '>' characters underneath them. Here is an ex- follow the start and end of the actual match are indicated in the out-
ample: put by '<' or '>' characters underneath them. Here is an example:
re> /(?<=pqr)abc(?=xyz)/ re> /(?<=pqr)abc(?=xyz)/
data> 123pqrabcxyz456\=allusedtext data> 123pqrabcxyz456\=allusedtext
0: pqrabcxyz 0: pqrabcxyz
<<< >>> <<< >>>
data> 123pqrabcxy\=ph,allusedtext
Partial match: pqrabcxy
<<<
This shows that the matched string is "abc", with the preceding and The first, complete match shows that the matched string is "abc", with
following strings "pqr" and "xyz" having been consulted during the the preceding and following strings "pqr" and "xyz" having been con-
match (when processing the assertions). sulted during the match (when processing the assertions). The partial
match can indicate only the preceding string.
The startchar modifier requests that the starting character for the The startchar modifier requests that the starting character for the
match be indicated, if it is different to the start of the matched match be indicated, if it is different to the start of the matched
string. The only time when this occurs is when \K has been processed as string. The only time when this occurs is when \K has been processed as
part of the match. In this situation, the output for the matched string part of the match. In this situation, the output for the matched string
is displayed from the starting character instead of from the match is displayed from the starting character instead of from the match
point, with circumflex characters under the earlier characters. For ex- point, with circumflex characters under the earlier characters. For ex-
ample: ample:
@ -1153,7 +1157,7 @@ SUBJECT MODIFIERS
0: abcxyz 0: abcxyz
^^^ ^^^
Unlike allusedtext, the startchar modifier can be used with JIT. How- Unlike allusedtext, the startchar modifier can be used with JIT. How-
ever, these two modifiers are mutually exclusive. ever, these two modifiers are mutually exclusive.
Showing the value of all capture groups Showing the value of all capture groups
@ -1161,97 +1165,97 @@ SUBJECT MODIFIERS
The allcaptures modifier requests that the values of all potential cap- The allcaptures modifier requests that the values of all potential cap-
tured parentheses be output after a match. By default, only those up to tured parentheses be output after a match. By default, only those up to
the highest one actually used in the match are output (corresponding to the highest one actually used in the match are output (corresponding to
the return code from pcre2_match()). Groups that did not take part in the return code from pcre2_match()). Groups that did not take part in
the match are output as "<unset>". This modifier is not relevant for the match are output as "<unset>". This modifier is not relevant for
DFA matching (which does no capturing) and does not apply when replace DFA matching (which does no capturing) and does not apply when replace
is specified; it is ignored, with a warning message, if present. is specified; it is ignored, with a warning message, if present.
Showing the entire ovector, for all outcomes Showing the entire ovector, for all outcomes
The allvector modifier requests that the entire ovector be shown, what- The allvector modifier requests that the entire ovector be shown, what-
ever the outcome of the match. Compare allcaptures, which shows only up ever the outcome of the match. Compare allcaptures, which shows only up
to the maximum number of capture groups for the pattern, and then only to the maximum number of capture groups for the pattern, and then only
for a successful complete non-DFA match. This modifier, which acts af- for a successful complete non-DFA match. This modifier, which acts af-
ter any match result, and also for DFA matching, provides a means of ter any match result, and also for DFA matching, provides a means of
checking that there are no unexpected modifications to ovector fields. checking that there are no unexpected modifications to ovector fields.
Before each match attempt, the ovector is filled with a special value, Before each match attempt, the ovector is filled with a special value,
and if this is found in both elements of a capturing pair, "<un- and if this is found in both elements of a capturing pair, "<un-
changed>" is output. After a successful match, this applies to all changed>" is output. After a successful match, this applies to all
groups after the maximum capture group for the pattern. In other cases groups after the maximum capture group for the pattern. In other cases
it applies to the entire ovector. After a partial match, the first two it applies to the entire ovector. After a partial match, the first two
elements are the only ones that should be set. After a DFA match, the elements are the only ones that should be set. After a DFA match, the
amount of ovector that is used depends on the number of matches that amount of ovector that is used depends on the number of matches that
were found. were found.
Testing pattern callouts Testing pattern callouts
A callout function is supplied when pcre2test calls the library match- A callout function is supplied when pcre2test calls the library match-
ing functions, unless callout_none is specified. Its behaviour can be ing functions, unless callout_none is specified. Its behaviour can be
controlled by various modifiers listed above whose names begin with controlled by various modifiers listed above whose names begin with
callout_. Details are given in the section entitled "Callouts" below. callout_. Details are given in the section entitled "Callouts" below.
Testing callouts from pcre2_substitute() is decribed separately in Testing callouts from pcre2_substitute() is decribed separately in
"Testing the substitution function" below. "Testing the substitution function" below.
Finding all matches in a string Finding all matches in a string
Searching for all possible matches within a subject can be requested by Searching for all possible matches within a subject can be requested by
the global or altglobal modifier. After finding a match, the matching the global or altglobal modifier. After finding a match, the matching
function is called again to search the remainder of the subject. The function is called again to search the remainder of the subject. The
difference between global and altglobal is that the former uses the difference between global and altglobal is that the former uses the
start_offset argument to pcre2_match() or pcre2_dfa_match() to start start_offset argument to pcre2_match() or pcre2_dfa_match() to start
searching at a new point within the entire string (which is what Perl searching at a new point within the entire string (which is what Perl
does), whereas the latter passes over a shortened subject. This makes a does), whereas the latter passes over a shortened subject. This makes a
difference to the matching process if the pattern begins with a lookbe- difference to the matching process if the pattern begins with a lookbe-
hind assertion (including \b or \B). hind assertion (including \b or \B).
If an empty string is matched, the next match is done with the If an empty string is matched, the next match is done with the
PCRE2_NOTEMPTY_ATSTART and PCRE2_ANCHORED flags set, in order to search PCRE2_NOTEMPTY_ATSTART and PCRE2_ANCHORED flags set, in order to search
for another, non-empty, match at the same point in the subject. If this for another, non-empty, match at the same point in the subject. If this
match fails, the start offset is advanced, and the normal match is re- match fails, the start offset is advanced, and the normal match is re-
tried. This imitates the way Perl handles such cases when using the /g tried. This imitates the way Perl handles such cases when using the /g
modifier or the split() function. Normally, the start offset is ad- modifier or the split() function. Normally, the start offset is ad-
vanced by one character, but if the newline convention recognizes CRLF vanced by one character, but if the newline convention recognizes CRLF
as a newline, and the current character is CR followed by LF, an ad- as a newline, and the current character is CR followed by LF, an ad-
vance of two characters occurs. vance of two characters occurs.
Testing substring extraction functions Testing substring extraction functions
The copy and get modifiers can be used to test the pcre2_sub- The copy and get modifiers can be used to test the pcre2_sub-
string_copy_xxx() and pcre2_substring_get_xxx() functions. They can be string_copy_xxx() and pcre2_substring_get_xxx() functions. They can be
given more than once, and each can specify a capture group name or num- given more than once, and each can specify a capture group name or num-
ber, for example: ber, for example:
abcd\=copy=1,copy=3,get=G1 abcd\=copy=1,copy=3,get=G1
If the #subject command is used to set default copy and/or get lists, If the #subject command is used to set default copy and/or get lists,
these can be unset by specifying a negative number to cancel all num- these can be unset by specifying a negative number to cancel all num-
bered groups and an empty name to cancel all named groups. bered groups and an empty name to cancel all named groups.
The getall modifier tests pcre2_substring_list_get(), which extracts The getall modifier tests pcre2_substring_list_get(), which extracts
all captured substrings. all captured substrings.
If the subject line is successfully matched, the substrings extracted If the subject line is successfully matched, the substrings extracted
by the convenience functions are output with C, G, or L after the by the convenience functions are output with C, G, or L after the
string number instead of a colon. This is in addition to the normal string number instead of a colon. This is in addition to the normal
full list. The string length (that is, the return from the extraction full list. The string length (that is, the return from the extraction
function) is given in parentheses after each substring, followed by the function) is given in parentheses after each substring, followed by the
name when the extraction was by name. name when the extraction was by name.
Testing the substitution function Testing the substitution function
If the replace modifier is set, the pcre2_substitute() function is If the replace modifier is set, the pcre2_substitute() function is
called instead of one of the matching functions. Note that replacement called instead of one of the matching functions. Note that replacement
strings cannot contain commas, because a comma signifies the end of a strings cannot contain commas, because a comma signifies the end of a
modifier. This is not thought to be an issue in a test program. modifier. This is not thought to be an issue in a test program.
Unlike subject strings, pcre2test does not process replacement strings Unlike subject strings, pcre2test does not process replacement strings
for escape sequences. In UTF mode, a replacement string is checked to for escape sequences. In UTF mode, a replacement string is checked to
see if it is a valid UTF-8 string. If so, it is correctly converted to see if it is a valid UTF-8 string. If so, it is correctly converted to
a UTF string of the appropriate code unit width. If it is not a valid a UTF string of the appropriate code unit width. If it is not a valid
UTF-8 string, the individual code units are copied directly. This pro- UTF-8 string, the individual code units are copied directly. This pro-
vides a means of passing an invalid UTF-8 string for testing purposes. vides a means of passing an invalid UTF-8 string for testing purposes.
The following modifiers set options (in additional to the normal match The following modifiers set options (in additional to the normal match
options) for pcre2_substitute(): options) for pcre2_substitute():
global PCRE2_SUBSTITUTE_GLOBAL global PCRE2_SUBSTITUTE_GLOBAL
@ -1261,8 +1265,8 @@ SUBJECT MODIFIERS
substitute_unset_empty PCRE2_SUBSTITUTE_UNSET_EMPTY substitute_unset_empty PCRE2_SUBSTITUTE_UNSET_EMPTY
After a successful substitution, the modified string is output, pre- After a successful substitution, the modified string is output, pre-
ceded by the number of replacements. This may be zero if there were no ceded by the number of replacements. This may be zero if there were no
matches. Here is a simple example of a substitution test: matches. Here is a simple example of a substitution test:
/abc/replace=xxx /abc/replace=xxx
@ -1271,12 +1275,12 @@ SUBJECT MODIFIERS
=abc=abc=\=global =abc=abc=\=global
2: =xxx=xxx= 2: =xxx=xxx=
Subject and replacement strings should be kept relatively short (fewer Subject and replacement strings should be kept relatively short (fewer
than 256 characters) for substitution tests, as fixed-size buffers are than 256 characters) for substitution tests, as fixed-size buffers are
used. To make it easy to test for buffer overflow, if the replacement used. To make it easy to test for buffer overflow, if the replacement
string starts with a number in square brackets, that number is passed string starts with a number in square brackets, that number is passed
to pcre2_substitute() as the size of the output buffer, with the re- to pcre2_substitute() as the size of the output buffer, with the re-
placement string starting at the next character. Here is an example placement string starting at the next character. Here is an example
that tests the edge case: that tests the edge case:
/abc/ /abc/
@ -1286,12 +1290,12 @@ SUBJECT MODIFIERS
Failed: error -47: no more memory Failed: error -47: no more memory
The default action of pcre2_substitute() is to return PCRE2_ER- The default action of pcre2_substitute() is to return PCRE2_ER-
ROR_NOMEMORY when the output buffer is too small. However, if the ROR_NOMEMORY when the output buffer is too small. However, if the
PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option is set (by using the substi- PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option is set (by using the substi-
tute_overflow_length modifier), pcre2_substitute() continues to go tute_overflow_length modifier), pcre2_substitute() continues to go
through the motions of matching and substituting (but not doing any through the motions of matching and substituting (but not doing any
callouts), in order to compute the size of buffer that is required. callouts), in order to compute the size of buffer that is required.
When this happens, pcre2test shows the required buffer length (which When this happens, pcre2test shows the required buffer length (which
includes space for the trailing zero) as part of the error message. For includes space for the trailing zero) as part of the error message. For
example: example:
@ -1300,15 +1304,15 @@ SUBJECT MODIFIERS
Failed: error -47: no more memory: 10 code units are needed Failed: error -47: no more memory: 10 code units are needed
A replacement string is ignored with POSIX and DFA matching. Specifying A replacement string is ignored with POSIX and DFA matching. Specifying
partial matching provokes an error return ("bad option value") from partial matching provokes an error return ("bad option value") from
pcre2_substitute(). pcre2_substitute().
Testing substitute callouts Testing substitute callouts
If the substitute_callout modifier is set, a substitution callout func- If the substitute_callout modifier is set, a substitution callout func-
tion is set up. The null_context modifier must not be set, because the tion is set up. The null_context modifier must not be set, because the
address of the callout function is passed in a match context. When the address of the callout function is passed in a match context. When the
callout function is called (after each substitution), details of the callout function is called (after each substitution), details of the
the input and output strings are output. For example: the input and output strings are output. For example:
/abc/g,replace=<$0>,substitute_callout /abc/g,replace=<$0>,substitute_callout
@ -1317,19 +1321,19 @@ SUBJECT MODIFIERS
2(1) Old 6 9 "abc" New 8 13 "<abc>" 2(1) Old 6 9 "abc" New 8 13 "<abc>"
2: <abc>def<abc>pqr 2: <abc>def<abc>pqr
The first number on each callout line is the count of matches. The The first number on each callout line is the count of matches. The
parenthesized number is the number of pairs that are set in the ovector parenthesized number is the number of pairs that are set in the ovector
(that is, one more than the number of capturing groups that were set). (that is, one more than the number of capturing groups that were set).
Then are listed the offsets of the old substring, its contents, and the Then are listed the offsets of the old substring, its contents, and the
same for the replacement. same for the replacement.
By default, the substitution callout function returns zero, which ac- By default, the substitution callout function returns zero, which ac-
cepts the replacement and causes matching to continue if /g was used. cepts the replacement and causes matching to continue if /g was used.
Two further modifiers can be used to test other return values. If sub- Two further modifiers can be used to test other return values. If sub-
stitute_skip is set to a value greater than zero the callout function stitute_skip is set to a value greater than zero the callout function
returns +1 for the match of that number, and similarly substitute_stop returns +1 for the match of that number, and similarly substitute_stop
returns -1. These cause the replacement to be rejected, and -1 causes returns -1. These cause the replacement to be rejected, and -1 causes
no further matching to take place. If either of them are set, substi- no further matching to take place. If either of them are set, substi-
tute_callout is assumed. For example: tute_callout is assumed. For example:
/abc/g,replace=<$0>,substitute_skip=1 /abc/g,replace=<$0>,substitute_skip=1
@ -1347,160 +1351,160 @@ SUBJECT MODIFIERS
Setting the JIT stack size Setting the JIT stack size
The jitstack modifier provides a way of setting the maximum stack size The jitstack modifier provides a way of setting the maximum stack size
that is used by the just-in-time optimization code. It is ignored if that is used by the just-in-time optimization code. It is ignored if
JIT optimization is not being used. The value is a number of kibibytes JIT optimization is not being used. The value is a number of kibibytes
(units of 1024 bytes). Setting zero reverts to the default of 32KiB. (units of 1024 bytes). Setting zero reverts to the default of 32KiB.
Providing a stack that is larger than the default is necessary only for Providing a stack that is larger than the default is necessary only for
very complicated patterns. If jitstack is set non-zero on a subject very complicated patterns. If jitstack is set non-zero on a subject
line it overrides any value that was set on the pattern. line it overrides any value that was set on the pattern.
Setting heap, match, and depth limits Setting heap, match, and depth limits
The heap_limit, match_limit, and depth_limit modifiers set the appro- The heap_limit, match_limit, and depth_limit modifiers set the appro-
priate limits in the match context. These values are ignored when the priate limits in the match context. These values are ignored when the
find_limits modifier is specified. find_limits modifier is specified.
Finding minimum limits Finding minimum limits
If the find_limits modifier is present on a subject line, pcre2test If the find_limits modifier is present on a subject line, pcre2test
calls the relevant matching function several times, setting different calls the relevant matching function several times, setting different
values in the match context via pcre2_set_heap_limit(), values in the match context via pcre2_set_heap_limit(),
pcre2_set_match_limit(), or pcre2_set_depth_limit() until it finds the pcre2_set_match_limit(), or pcre2_set_depth_limit() until it finds the
minimum values for each parameter that allows the match to complete minimum values for each parameter that allows the match to complete
without error. If JIT is being used, only the match limit is relevant. without error. If JIT is being used, only the match limit is relevant.
When using this modifier, the pattern should not contain any limit set- When using this modifier, the pattern should not contain any limit set-
tings such as (*LIMIT_MATCH=...) within it. If such a setting is tings such as (*LIMIT_MATCH=...) within it. If such a setting is
present and is lower than the minimum matching value, the minimum value present and is lower than the minimum matching value, the minimum value
cannot be found because pcre2_set_match_limit() etc. are only able to cannot be found because pcre2_set_match_limit() etc. are only able to
reduce the value of an in-pattern limit; they cannot increase it. reduce the value of an in-pattern limit; they cannot increase it.
For non-DFA matching, the minimum depth_limit number is a measure of For non-DFA matching, the minimum depth_limit number is a measure of
how much nested backtracking happens (that is, how deeply the pattern's how much nested backtracking happens (that is, how deeply the pattern's
tree is searched). In the case of DFA matching, depth_limit controls tree is searched). In the case of DFA matching, depth_limit controls
the depth of recursive calls of the internal function that is used for the depth of recursive calls of the internal function that is used for
handling pattern recursion, lookaround assertions, and atomic groups. handling pattern recursion, lookaround assertions, and atomic groups.
For non-DFA matching, the match_limit number is a measure of the amount For non-DFA matching, the match_limit number is a measure of the amount
of backtracking that takes place, and learning the minimum value can be of backtracking that takes place, and learning the minimum value can be
instructive. For most simple matches, the number is quite small, but instructive. For most simple matches, the number is quite small, but
for patterns with very large numbers of matching possibilities, it can for patterns with very large numbers of matching possibilities, it can
become large very quickly with increasing length of subject string. In become large very quickly with increasing length of subject string. In
the case of DFA matching, match_limit controls the total number of the case of DFA matching, match_limit controls the total number of
calls, both recursive and non-recursive, to the internal matching func- calls, both recursive and non-recursive, to the internal matching func-
tion, thus controlling the overall amount of computing resource that is tion, thus controlling the overall amount of computing resource that is
used. used.
For both kinds of matching, the heap_limit number, which is in For both kinds of matching, the heap_limit number, which is in
kibibytes (units of 1024 bytes), limits the amount of heap memory used kibibytes (units of 1024 bytes), limits the amount of heap memory used
for matching. A value of zero disables the use of any heap memory; many for matching. A value of zero disables the use of any heap memory; many
simple pattern matches can be done without using the heap, so zero is simple pattern matches can be done without using the heap, so zero is
not an unreasonable setting. not an unreasonable setting.
Showing MARK names Showing MARK names
The mark modifier causes the names from backtracking control verbs that The mark modifier causes the names from backtracking control verbs that
are returned from calls to pcre2_match() to be displayed. If a mark is are returned from calls to pcre2_match() to be displayed. If a mark is
returned for a match, non-match, or partial match, pcre2test shows it. returned for a match, non-match, or partial match, pcre2test shows it.
For a match, it is on a line by itself, tagged with "MK:". Otherwise, For a match, it is on a line by itself, tagged with "MK:". Otherwise,
it is added to the non-match message. it is added to the non-match message.
Showing memory usage Showing memory usage
The memory modifier causes pcre2test to log the sizes of all heap mem- The memory modifier causes pcre2test to log the sizes of all heap mem-
ory allocation and freeing calls that occur during a call to ory allocation and freeing calls that occur during a call to
pcre2_match() or pcre2_dfa_match(). These occur only when a match re- pcre2_match() or pcre2_dfa_match(). These occur only when a match re-
quires a bigger vector than the default for remembering backtracking quires a bigger vector than the default for remembering backtracking
points (pcre2_match()) or for internal workspace (pcre2_dfa_match()). points (pcre2_match()) or for internal workspace (pcre2_dfa_match()).
In many cases there will be no heap memory used and therefore no addi- In many cases there will be no heap memory used and therefore no addi-
tional output. No heap memory is allocated during matching with JIT, so tional output. No heap memory is allocated during matching with JIT, so
in that case the memory modifier never has any effect. For this modi- in that case the memory modifier never has any effect. For this modi-
fier to work, the null_context modifier must not be set on both the fier to work, the null_context modifier must not be set on both the
pattern and the subject, though it can be set on one or the other. pattern and the subject, though it can be set on one or the other.
Setting a starting offset Setting a starting offset
The offset modifier sets an offset in the subject string at which The offset modifier sets an offset in the subject string at which
matching starts. Its value is a number of code units, not characters. matching starts. Its value is a number of code units, not characters.
Setting an offset limit Setting an offset limit
The offset_limit modifier sets a limit for unanchored matches. If a The offset_limit modifier sets a limit for unanchored matches. If a
match cannot be found starting at or before this offset in the subject, match cannot be found starting at or before this offset in the subject,
a "no match" return is given. The data value is a number of code units, a "no match" return is given. The data value is a number of code units,
not characters. When this modifier is used, the use_offset_limit modi- not characters. When this modifier is used, the use_offset_limit modi-
fier must have been set for the pattern; if not, an error is generated. fier must have been set for the pattern; if not, an error is generated.
Setting the size of the output vector Setting the size of the output vector
The ovector modifier applies only to the subject line in which it ap- The ovector modifier applies only to the subject line in which it ap-
pears, though of course it can also be used to set a default in a #sub- pears, though of course it can also be used to set a default in a #sub-
ject command. It specifies the number of pairs of offsets that are ject command. It specifies the number of pairs of offsets that are
available for storing matching information. The default is 15. available for storing matching information. The default is 15.
A value of zero is useful when testing the POSIX API because it causes A value of zero is useful when testing the POSIX API because it causes
regexec() to be called with a NULL capture vector. When not testing the regexec() to be called with a NULL capture vector. When not testing the
POSIX API, a value of zero is used to cause pcre2_match_data_cre- POSIX API, a value of zero is used to cause pcre2_match_data_cre-
ate_from_pattern() to be called, in order to create a match block of ate_from_pattern() to be called, in order to create a match block of
exactly the right size for the pattern. (It is not possible to create a exactly the right size for the pattern. (It is not possible to create a
match block with a zero-length ovector; there is always at least one match block with a zero-length ovector; there is always at least one
pair of offsets.) pair of offsets.)
Passing the subject as zero-terminated Passing the subject as zero-terminated
By default, the subject string is passed to a native API matching func- By default, the subject string is passed to a native API matching func-
tion with its correct length. In order to test the facility for passing tion with its correct length. In order to test the facility for passing
a zero-terminated string, the zero_terminate modifier is provided. It a zero-terminated string, the zero_terminate modifier is provided. It
causes the length to be passed as PCRE2_ZERO_TERMINATED. When matching causes the length to be passed as PCRE2_ZERO_TERMINATED. When matching
via the POSIX interface, this modifier is ignored, with a warning. via the POSIX interface, this modifier is ignored, with a warning.
When testing pcre2_substitute(), this modifier also has the effect of When testing pcre2_substitute(), this modifier also has the effect of
passing the replacement string as zero-terminated. passing the replacement string as zero-terminated.
Passing a NULL context Passing a NULL context
Normally, pcre2test passes a context block to pcre2_match(), Normally, pcre2test passes a context block to pcre2_match(),
pcre2_dfa_match(), pcre2_jit_match() or pcre2_substitute(). If the pcre2_dfa_match(), pcre2_jit_match() or pcre2_substitute(). If the
null_context modifier is set, however, NULL is passed. This is for null_context modifier is set, however, NULL is passed. This is for
testing that the matching and substitution functions behave correctly testing that the matching and substitution functions behave correctly
in this case (they use default values). This modifier cannot be used in this case (they use default values). This modifier cannot be used
with the find_limits or substitute_callout modifiers. with the find_limits or substitute_callout modifiers.
THE ALTERNATIVE MATCHING FUNCTION THE ALTERNATIVE MATCHING FUNCTION
By default, pcre2test uses the standard PCRE2 matching function, By default, pcre2test uses the standard PCRE2 matching function,
pcre2_match() to match each subject line. PCRE2 also supports an alter- pcre2_match() to match each subject line. PCRE2 also supports an alter-
native matching function, pcre2_dfa_match(), which operates in a dif- native matching function, pcre2_dfa_match(), which operates in a dif-
ferent way, and has some restrictions. The differences between the two ferent way, and has some restrictions. The differences between the two
functions are described in the pcre2matching documentation. functions are described in the pcre2matching documentation.
If the dfa modifier is set, the alternative matching function is used. If the dfa modifier is set, the alternative matching function is used.
This function finds all possible matches at a given point in the sub- This function finds all possible matches at a given point in the sub-
ject. If, however, the dfa_shortest modifier is set, processing stops ject. If, however, the dfa_shortest modifier is set, processing stops
after the first match is found. This is always the shortest possible after the first match is found. This is always the shortest possible
match. match.
DEFAULT OUTPUT FROM pcre2test DEFAULT OUTPUT FROM pcre2test
This section describes the output when the normal matching function, This section describes the output when the normal matching function,
pcre2_match(), is being used. pcre2_match(), is being used.
When a match succeeds, pcre2test outputs the list of captured sub- When a match succeeds, pcre2test outputs the list of captured sub-
strings, starting with number 0 for the string that matched the whole strings, starting with number 0 for the string that matched the whole
pattern. Otherwise, it outputs "No match" when the return is PCRE2_ER- pattern. Otherwise, it outputs "No match" when the return is PCRE2_ER-
ROR_NOMATCH, or "Partial match:" followed by the partially matching ROR_NOMATCH, or "Partial match:" followed by the partially matching
substring when the return is PCRE2_ERROR_PARTIAL. (Note that this is substring when the return is PCRE2_ERROR_PARTIAL. (Note that this is
the entire substring that was inspected during the partial match; it the entire substring that was inspected during the partial match; it
may include characters before the actual match start if a lookbehind may include characters before the actual match start if a lookbehind
assertion, \K, \b, or \B was involved.) assertion, \K, \b, or \B was involved.)
For any other return, pcre2test outputs the PCRE2 negative error number For any other return, pcre2test outputs the PCRE2 negative error number
and a short descriptive phrase. If the error is a failed UTF string and a short descriptive phrase. If the error is a failed UTF string
check, the code unit offset of the start of the failing character is check, the code unit offset of the start of the failing character is
also output. Here is an example of an interactive pcre2test run. also output. Here is an example of an interactive pcre2test run.
$ pcre2test $ pcre2test
@ -1516,8 +1520,8 @@ DEFAULT OUTPUT FROM pcre2test
Unset capturing substrings that are not followed by one that is set are Unset capturing substrings that are not followed by one that is set are
not shown by pcre2test unless the allcaptures modifier is specified. In not shown by pcre2test unless the allcaptures modifier is specified. In
the following example, there are two capturing substrings, but when the the following example, there are two capturing substrings, but when the
first data line is matched, the second, unset substring is not shown. first data line is matched, the second, unset substring is not shown.
An "internal" unset substring is shown as "<unset>", as for the second An "internal" unset substring is shown as "<unset>", as for the second
data line. data line.
re> /(a)|(b)/ re> /(a)|(b)/
@ -1529,11 +1533,11 @@ DEFAULT OUTPUT FROM pcre2test
1: <unset> 1: <unset>
2: b 2: b
If the strings contain any non-printing characters, they are output as If the strings contain any non-printing characters, they are output as
\xhh escapes if the value is less than 256 and UTF mode is not set. \xhh escapes if the value is less than 256 and UTF mode is not set.
Otherwise they are output as \x{hh...} escapes. See below for the defi- Otherwise they are output as \x{hh...} escapes. See below for the defi-
nition of non-printing characters. If the aftertext modifier is set, nition of non-printing characters. If the aftertext modifier is set,
the output for substring 0 is followed by the the rest of the subject the output for substring 0 is followed by the the rest of the subject
string, identified by "0+" like this: string, identified by "0+" like this:
re> /cat/aftertext re> /cat/aftertext
@ -1553,8 +1557,8 @@ DEFAULT OUTPUT FROM pcre2test
0: ipp 0: ipp
1: pp 1: pp
"No match" is output only if the first match attempt fails. Here is an "No match" is output only if the first match attempt fails. Here is an
example of a failure message (the offset 4 that is specified by the example of a failure message (the offset 4 that is specified by the
offset modifier is past the end of the subject string): offset modifier is past the end of the subject string):
re> /xyz/ re> /xyz/
@ -1562,7 +1566,7 @@ DEFAULT OUTPUT FROM pcre2test
Error -24 (bad offset value) Error -24 (bad offset value)
Note that whereas patterns can be continued over several lines (a plain Note that whereas patterns can be continued over several lines (a plain
">" prompt is used for continuations), subject lines may not. However ">" prompt is used for continuations), subject lines may not. However
newlines can be included in a subject by means of the \n escape (or \r, newlines can be included in a subject by means of the \n escape (or \r,
\r\n, etc., depending on the newline sequence setting). \r\n, etc., depending on the newline sequence setting).
@ -1570,7 +1574,7 @@ DEFAULT OUTPUT FROM pcre2test
OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
When the alternative matching function, pcre2_dfa_match(), is used, the When the alternative matching function, pcre2_dfa_match(), is used, the
output consists of a list of all the matches that start at the first output consists of a list of all the matches that start at the first
point in the subject where there is at least one match. For example: point in the subject where there is at least one match. For example:
re> /(tang|tangerine|tan)/ re> /(tang|tangerine|tan)/
@ -1579,11 +1583,11 @@ OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
1: tang 1: tang
2: tan 2: tan
Using the normal matching function on this data finds only "tang". The Using the normal matching function on this data finds only "tang". The
longest matching string is always given first (and numbered zero). Af- longest matching string is always given first (and numbered zero). Af-
ter a PCRE2_ERROR_PARTIAL return, the output is "Partial match:", fol- ter a PCRE2_ERROR_PARTIAL return, the output is "Partial match:", fol-
lowed by the partially matching substring. Note that this is the entire lowed by the partially matching substring. Note that this is the entire
substring that was inspected during the partial match; it may include substring that was inspected during the partial match; it may include
characters before the actual match start if a lookbehind assertion, \b, characters before the actual match start if a lookbehind assertion, \b,
or \B was involved. (\K is not supported for DFA matching.) or \B was involved. (\K is not supported for DFA matching.)
@ -1599,16 +1603,16 @@ OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
1: tan 1: tan
0: tan 0: tan
The alternative matching function does not support substring capture, The alternative matching function does not support substring capture,
so the modifiers that are concerned with captured substrings are not so the modifiers that are concerned with captured substrings are not
relevant. relevant.
RESTARTING AFTER A PARTIAL MATCH RESTARTING AFTER A PARTIAL MATCH
When the alternative matching function has given the PCRE2_ERROR_PAR- When the alternative matching function has given the PCRE2_ERROR_PAR-
TIAL return, indicating that the subject partially matched the pattern, TIAL return, indicating that the subject partially matched the pattern,
you can restart the match with additional subject data by means of the you can restart the match with additional subject data by means of the
dfa_restart modifier. For example: dfa_restart modifier. For example:
re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/ re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
@ -1617,37 +1621,37 @@ RESTARTING AFTER A PARTIAL MATCH
data> n05\=dfa,dfa_restart data> n05\=dfa,dfa_restart
0: n05 0: n05
For further information about partial matching, see the pcre2partial For further information about partial matching, see the pcre2partial
documentation. documentation.
CALLOUTS CALLOUTS
If the pattern contains any callout requests, pcre2test's callout func- If the pattern contains any callout requests, pcre2test's callout func-
tion is called during matching unless callout_none is specified. This tion is called during matching unless callout_none is specified. This
works with both matching functions, and with JIT, though there are some works with both matching functions, and with JIT, though there are some
differences in behaviour. The output for callouts with numerical argu- differences in behaviour. The output for callouts with numerical argu-
ments and those with string arguments is slightly different. ments and those with string arguments is slightly different.
Callouts with numerical arguments Callouts with numerical arguments
By default, the callout function displays the callout number, the start By default, the callout function displays the callout number, the start
and current positions in the subject text at the callout time, and the and current positions in the subject text at the callout time, and the
next pattern item to be tested. For example: next pattern item to be tested. For example:
--->pqrabcdef --->pqrabcdef
0 ^ ^ \d 0 ^ ^ \d
This output indicates that callout number 0 occurred for a match at- This output indicates that callout number 0 occurred for a match at-
tempt starting at the fourth character of the subject string, when the tempt starting at the fourth character of the subject string, when the
pointer was at the seventh character, and when the next pattern item pointer was at the seventh character, and when the next pattern item
was \d. Just one circumflex is output if the start and current posi- was \d. Just one circumflex is output if the start and current posi-
tions are the same, or if the current position precedes the start posi- tions are the same, or if the current position precedes the start posi-
tion, which can happen if the callout is in a lookbehind assertion. tion, which can happen if the callout is in a lookbehind assertion.
Callouts numbered 255 are assumed to be automatic callouts, inserted as Callouts numbered 255 are assumed to be automatic callouts, inserted as
a result of the auto_callout pattern modifier. In this case, instead of a result of the auto_callout pattern modifier. In this case, instead of
showing the callout number, the offset in the pattern, preceded by a showing the callout number, the offset in the pattern, preceded by a
plus, is output. For example: plus, is output. For example:
re> /\d?[A-E]\*/auto_callout re> /\d?[A-E]\*/auto_callout
@ -1674,17 +1678,17 @@ CALLOUTS
+12 ^ ^ +12 ^ ^
0: abc 0: abc
The mark changes between matching "a" and "b", but stays the same for The mark changes between matching "a" and "b", but stays the same for
the rest of the match, so nothing more is output. If, as a result of the rest of the match, so nothing more is output. If, as a result of
backtracking, the mark reverts to being unset, the text "<unset>" is backtracking, the mark reverts to being unset, the text "<unset>" is
output. output.
Callouts with string arguments Callouts with string arguments
The output for a callout with a string argument is similar, except that The output for a callout with a string argument is similar, except that
instead of outputting a callout number before the position indicators, instead of outputting a callout number before the position indicators,
the callout string and its offset in the pattern string are output be- the callout string and its offset in the pattern string are output be-
fore the reflection of the subject string, and the subject string is fore the reflection of the subject string, and the subject string is
reflected for each callout. For example: reflected for each callout. For example:
re> /^ab(?C'first')cd(?C"second")ef/ re> /^ab(?C'first')cd(?C"second")ef/
@ -1700,26 +1704,26 @@ CALLOUTS
Callout modifiers Callout modifiers
The callout function in pcre2test returns zero (carry on matching) by The callout function in pcre2test returns zero (carry on matching) by
default, but you can use a callout_fail modifier in a subject line to default, but you can use a callout_fail modifier in a subject line to
change this and other parameters of the callout (see below). change this and other parameters of the callout (see below).
If the callout_capture modifier is set, the current captured groups are If the callout_capture modifier is set, the current captured groups are
output when a callout occurs. This is useful only for non-DFA matching, output when a callout occurs. This is useful only for non-DFA matching,
as pcre2_dfa_match() does not support capturing, so no captures are as pcre2_dfa_match() does not support capturing, so no captures are
ever shown. ever shown.
The normal callout output, showing the callout number or pattern offset The normal callout output, showing the callout number or pattern offset
(as described above) is suppressed if the callout_no_where modifier is (as described above) is suppressed if the callout_no_where modifier is
set. set.
When using the interpretive matching function pcre2_match() without When using the interpretive matching function pcre2_match() without
JIT, setting the callout_extra modifier causes additional output from JIT, setting the callout_extra modifier causes additional output from
pcre2test's callout function to be generated. For the first callout in pcre2test's callout function to be generated. For the first callout in
a match attempt at a new starting position in the subject, "New match a match attempt at a new starting position in the subject, "New match
attempt" is output. If there has been a backtrack since the last call- attempt" is output. If there has been a backtrack since the last call-
out (or start of matching if this is the first callout), "Backtrack" is out (or start of matching if this is the first callout), "Backtrack" is
output, followed by "No other matching paths" if the backtrack ended output, followed by "No other matching paths" if the backtrack ended
the previous match attempt. For example: the previous match attempt. For example:
re> /(a+)b/auto_callout,no_start_optimize,no_auto_possess re> /(a+)b/auto_callout,no_start_optimize,no_auto_possess
@ -1756,86 +1760,86 @@ CALLOUTS
+1 ^ a+ +1 ^ a+
No match No match
Notice that various optimizations must be turned off if you want all Notice that various optimizations must be turned off if you want all
possible matching paths to be scanned. If no_start_optimize is not possible matching paths to be scanned. If no_start_optimize is not
used, there is an immediate "no match", without any callouts, because used, there is an immediate "no match", without any callouts, because
the starting optimization fails to find "b" in the subject, which it the starting optimization fails to find "b" in the subject, which it
knows must be present for any match. If no_auto_possess is not used, knows must be present for any match. If no_auto_possess is not used,
the "a+" item is turned into "a++", which reduces the number of back- the "a+" item is turned into "a++", which reduces the number of back-
tracks. tracks.
The callout_extra modifier has no effect if used with the DFA matching The callout_extra modifier has no effect if used with the DFA matching
function, or with JIT. function, or with JIT.
Return values from callouts Return values from callouts
The default return from the callout function is zero, which allows The default return from the callout function is zero, which allows
matching to continue. The callout_fail modifier can be given one or two matching to continue. The callout_fail modifier can be given one or two
numbers. If there is only one number, 1 is returned instead of 0 (caus- numbers. If there is only one number, 1 is returned instead of 0 (caus-
ing matching to backtrack) when a callout of that number is reached. If ing matching to backtrack) when a callout of that number is reached. If
two numbers (<n>:<m>) are given, 1 is returned when callout <n> is two numbers (<n>:<m>) are given, 1 is returned when callout <n> is
reached and there have been at least <m> callouts. The callout_error reached and there have been at least <m> callouts. The callout_error
modifier is similar, except that PCRE2_ERROR_CALLOUT is returned, caus- modifier is similar, except that PCRE2_ERROR_CALLOUT is returned, caus-
ing the entire matching process to be aborted. If both these modifiers ing the entire matching process to be aborted. If both these modifiers
are set for the same callout number, callout_error takes precedence. are set for the same callout number, callout_error takes precedence.
Note that callouts with string arguments are always given the number Note that callouts with string arguments are always given the number
zero. zero.
The callout_data modifier can be given an unsigned or a negative num- The callout_data modifier can be given an unsigned or a negative num-
ber. This is set as the "user data" that is passed to the matching ber. This is set as the "user data" that is passed to the matching
function, and passed back when the callout function is invoked. Any function, and passed back when the callout function is invoked. Any
value other than zero is used as a return from pcre2test's callout value other than zero is used as a return from pcre2test's callout
function. function.
Inserting callouts can be helpful when using pcre2test to check compli- Inserting callouts can be helpful when using pcre2test to check compli-
cated regular expressions. For further information about callouts, see cated regular expressions. For further information about callouts, see
the pcre2callout documentation. the pcre2callout documentation.
NON-PRINTING CHARACTERS NON-PRINTING CHARACTERS
When pcre2test is outputting text in the compiled version of a pattern, When pcre2test is outputting text in the compiled version of a pattern,
bytes other than 32-126 are always treated as non-printing characters bytes other than 32-126 are always treated as non-printing characters
and are therefore shown as hex escapes. and are therefore shown as hex escapes.
When pcre2test is outputting text that is a matched part of a subject When pcre2test is outputting text that is a matched part of a subject
string, it behaves in the same way, unless a different locale has been string, it behaves in the same way, unless a different locale has been
set for the pattern (using the locale modifier). In this case, the is- set for the pattern (using the locale modifier). In this case, the is-
print() function is used to distinguish printing and non-printing char- print() function is used to distinguish printing and non-printing char-
acters. acters.
SAVING AND RESTORING COMPILED PATTERNS SAVING AND RESTORING COMPILED PATTERNS
It is possible to save compiled patterns on disc or elsewhere, and It is possible to save compiled patterns on disc or elsewhere, and
reload them later, subject to a number of restrictions. JIT data cannot reload them later, subject to a number of restrictions. JIT data cannot
be saved. The host on which the patterns are reloaded must be running be saved. 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 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 have the same endianness, pointer width and PCRE2_SIZE type. Before
compiled patterns can be saved they must be serialized, that is, con- compiled patterns can be saved they must be serialized, that is, con-
verted to a stream of bytes. A single byte stream may contain any num- verted to a stream of bytes. A single byte stream may contain any num-
ber of compiled patterns, but they must all use the same character ta- ber of compiled patterns, but they must all use the same character ta-
bles. A single copy of the tables is included in the byte stream (its bles. A single copy of the tables is included in the byte stream (its
size is 1088 bytes). size is 1088 bytes).
The functions whose names begin with pcre2_serialize_ are used for se- The functions whose names begin with pcre2_serialize_ are used for se-
rializing and de-serializing. They are described in the pcre2serialize rializing and de-serializing. They are described in the pcre2serialize
documentation. In this section we describe the features of pcre2test documentation. In this section we describe the features of pcre2test
that can be used to test these functions. that can be used to test these functions.
Note that "serialization" in PCRE2 does not convert compiled patterns Note that "serialization" in PCRE2 does not convert compiled patterns
to an abstract format like Java or .NET. It just makes a reloadable to an abstract format like Java or .NET. It just makes a reloadable
byte code stream. Hence the restrictions on reloading mentioned above. byte code stream. Hence the restrictions on reloading mentioned above.
In pcre2test, when a pattern with push modifier is successfully com- In pcre2test, when a pattern with push modifier is successfully com-
piled, it is pushed onto a stack of compiled patterns, and pcre2test piled, it is pushed onto a stack of compiled patterns, and pcre2test
expects the next line to contain a new pattern (or command) instead of expects the next line to contain a new pattern (or command) instead of
a subject line. By contrast, the pushcopy modifier causes a copy of the a subject line. By contrast, the pushcopy modifier causes a copy of the
compiled pattern to be stacked, leaving the original available for im- compiled pattern to be stacked, leaving the original available for im-
mediate matching. By using push and/or pushcopy, a number of patterns mediate matching. By using push and/or pushcopy, a number of patterns
can be compiled and retained. These modifiers are incompatible with can be compiled and retained. These modifiers are incompatible with
posix, and control modifiers that act at match time are ignored (with a posix, and control modifiers that act at match time are ignored (with a
message) for the stacked patterns. The jitverify modifier applies only message) for the stacked patterns. The jitverify modifier applies only
at compile time. at compile time.
The command The command
@ -1843,21 +1847,21 @@ SAVING AND RESTORING COMPILED PATTERNS
#save <filename> #save <filename>
causes all the stacked patterns to be serialized and the result written causes all the stacked patterns to be serialized and the result written
to the named file. Afterwards, all the stacked patterns are freed. The to the named file. Afterwards, all the stacked patterns are freed. The
command command
#load <filename> #load <filename>
reads the data in the file, and then arranges for it to be de-serial- reads the data in the file, and then arranges for it to be de-serial-
ized, with the resulting compiled patterns added to the pattern stack. ized, with the resulting compiled patterns added to the pattern stack.
The pattern on the top of the stack can be retrieved by the #pop com- The pattern on the top of the stack can be retrieved by the #pop com-
mand, which must be followed by lines of subjects that are to be mand, which must be followed by lines of subjects that are to be
matched with the pattern, terminated as usual by an empty line or end matched with the pattern, terminated as usual by an empty line or end
of file. This command may be followed by a modifier list containing of file. This command may be followed by a modifier list containing
only control modifiers that act after a pattern has been compiled. In only control modifiers that act after a pattern has been compiled. In
particular, hex, posix, posix_nosub, push, and pushcopy are not al- particular, hex, posix, posix_nosub, push, and pushcopy are not al-
lowed, nor are any option-setting modifiers. The JIT modifiers are, lowed, nor are any option-setting modifiers. The JIT modifiers are,
however permitted. Here is an example that saves and reloads two pat- however permitted. Here is an example that saves and reloads two pat-
terns. terns.
/abc/push /abc/push
@ -1870,10 +1874,10 @@ SAVING AND RESTORING COMPILED PATTERNS
#pop jit,bincode #pop jit,bincode
abc abc
If jitverify is used with #pop, it does not automatically imply jit, If jitverify is used with #pop, it does not automatically imply jit,
which is different behaviour from when it is used on a pattern. which is different behaviour from when it is used on a pattern.
The #popcopy command is analagous to the pushcopy modifier in that it The #popcopy command is analagous to the pushcopy modifier in that it
makes current a copy of the topmost stack pattern, leaving the original makes current a copy of the topmost stack pattern, leaving the original
still on the stack. still on the stack.
@ -1893,5 +1897,5 @@ AUTHOR
REVISION REVISION
Last updated: 20 June 2019 Last updated: 26 June 2019
Copyright (c) 1997-2019 University of Cambridge. Copyright (c) 1997-2019 University of Cambridge.

15
src/pcre2test.c
View File

@ -7761,14 +7761,22 @@ for (gmatched = 0;; gmatched++)
} /* End of handling a successful match */ } /* End of handling a successful match */
/* There was a partial match. The value of ovector[0] is the bumpalong point, /* There was a partial match. The value of ovector[0] is the bumpalong point,
that is, startchar, not any \K point that might have been passed. */ that is, startchar, not any \K point that might have been passed. When JIT is
not in use, "allusedtext" may be set, in which case we indicate the leftmost
consulted character. */
else if (capcount == PCRE2_ERROR_PARTIAL) else if (capcount == PCRE2_ERROR_PARTIAL)
{ {
PCRE2_SIZE poffset; PCRE2_SIZE leftchar;
int backlength; int backlength;
int rubriclength = 0; int rubriclength = 0;
if ((dat_datctl.control & CTL_ALLUSEDTEXT) != 0)
{
leftchar = FLD(match_data, leftchar);
}
else leftchar = ovector[0];
fprintf(outfile, "Partial match"); fprintf(outfile, "Partial match");
if ((dat_datctl.control & CTL_MARK) != 0 && if ((dat_datctl.control & CTL_MARK) != 0 &&
TESTFLD(match_data, mark, !=, NULL)) TESTFLD(match_data, mark, !=, NULL))
@ -7781,8 +7789,7 @@ for (gmatched = 0;; gmatched++)
fprintf(outfile, ": "); fprintf(outfile, ": ");
rubriclength += 15; rubriclength += 15;
poffset = backchars(pp, ovector[0], maxlookbehind, utf); PCHARS(backlength, pp, leftchar, ovector[0] - leftchar, utf, outfile);
PCHARS(backlength, pp, poffset, ovector[0] - poffset, utf, outfile);
PCHARSV(pp, ovector[0], ulen - ovector[0], utf, outfile); PCHARSV(pp, ovector[0], ulen - ovector[0], utf, outfile);
if ((pat_patctl.control & CTL_JITVERIFY) != 0 && jit_was_used) if ((pat_patctl.control & CTL_JITVERIFY) != 0 && jit_was_used)

38
testdata/testinput15 vendored
View File

@ -122,6 +122,44 @@
/abc(?=abcde)(?=ab)/allusedtext /abc(?=abcde)(?=ab)/allusedtext
abcabcdefg abcabcdefg
#subject allusedtext
/(?<=abc)123/
xyzabc123pqr
xyzabc12\=ps
xyzabc12\=ph
/\babc\b/
+++abc+++
+++ab\=ps
+++ab\=ph
/(?<=abc)def/
abc\=ph
/(?<=123)(*MARK:xx)abc/mark
xxxx123a\=ph
xxxx123a\=ps
/(?<=(?<=a)b)c.*/I
abc\=ph
\= Expect no match
xbc\=ph
/(?<=ab)c.*/I
abc\=ph
\= Expect no match
xbc\=ph
/abc(?<=bc)def/
xxxabcd\=ph
/(?<=ab)cdef/
xxabcd\=ph
#subject
# -------------------------------------------------------------------
# These tests provoke recursion loops, which give a different error message # These tests provoke recursion loops, which give a different error message
# when JIT is used. # when JIT is used.

8
testdata/testinput6 vendored
View File

@ -486,7 +486,7 @@
def\=dfa_restart def\=dfa_restart
/(?<=foo)bar/ /(?<=foo)bar/
foob\=ps,offset=2 foob\=ps,offset=2,allusedtext
foobar...\=ps,dfa_restart,offset=4 foobar...\=ps,dfa_restart,offset=4
foobar\=offset=2 foobar\=offset=2
\= Expect no match \= Expect no match
@ -4415,12 +4415,12 @@
/abc\K123/ /abc\K123/
xyzabc123pqr xyzabc123pqr
/(?<=abc)123/ /(?<=abc)123/allusedtext
xyzabc123pqr xyzabc123pqr
xyzabc12\=ps xyzabc12\=ps
xyzabc12\=ph xyzabc12\=ph
/\babc\b/ /\babc\b/allusedtext
+++abc+++ +++abc+++
+++ab\=ps +++ab\=ps
+++ab\=ph +++ab\=ph
@ -4490,7 +4490,7 @@
/^(?(?!a(*SKIP)b))/ /^(?(?!a(*SKIP)b))/
ac ac
/(?<=abc)def/ /(?<=abc)def/allusedtext
abc\=ph abc\=ph
/abc$/ /abc$/

73
testdata/testoutput15 vendored
View File

@ -265,6 +265,79 @@ Failed: error -52: nested recursion at the same subject position
0: abcabcde 0: abcabcde
>>>>> >>>>>
#subject allusedtext
/(?<=abc)123/
xyzabc123pqr
0: abc123
<<<
xyzabc12\=ps
Partial match: abc12
<<<
xyzabc12\=ph
Partial match: abc12
<<<
/\babc\b/
+++abc+++
0: +abc+
< >
+++ab\=ps
Partial match: +ab
<
+++ab\=ph
Partial match: +ab
<
/(?<=abc)def/
abc\=ph
Partial match: abc
<<<
/(?<=123)(*MARK:xx)abc/mark
xxxx123a\=ph
Partial match, mark=xx: 123a
<<<
xxxx123a\=ps
Partial match, mark=xx: 123a
<<<
/(?<=(?<=a)b)c.*/I
Capture group count = 0
Max lookbehind = 2
First code unit = 'c'
Subject length lower bound = 1
abc\=ph
Partial match: abc
<<
\= Expect no match
xbc\=ph
No match
/(?<=ab)c.*/I
Capture group count = 0
Max lookbehind = 2
First code unit = 'c'
Subject length lower bound = 1
abc\=ph
Partial match: abc
<<
\= Expect no match
xbc\=ph
No match
/abc(?<=bc)def/
xxxabcd\=ph
Partial match: abcd
/(?<=ab)cdef/
xxabcd\=ph
Partial match: abcd
<<
#subject
# -------------------------------------------------------------------
# These tests provoke recursion loops, which give a different error message # These tests provoke recursion loops, which give a different error message
# when JIT is used. # when JIT is used.

27
testdata/testoutput2 vendored
View File

@ -9369,21 +9369,17 @@ Partial match: abc12
xyzabc123pqr xyzabc123pqr
0: 123 0: 123
xyzabc12\=ps xyzabc12\=ps
Partial match: abc12 Partial match: 12
<<<
xyzabc12\=ph xyzabc12\=ph
Partial match: abc12 Partial match: 12
<<<
/\babc\b/ /\babc\b/
+++abc+++ +++abc+++
0: abc 0: abc
+++ab\=ps +++ab\=ps
Partial match: +ab Partial match: ab
<
+++ab\=ph +++ab\=ph
Partial match: +ab Partial match: ab
<
/(?&word)(?&element)(?(DEFINE)(?<element><[^m][^>]>[^<])(?<word>\w*+))/B /(?&word)(?&element)(?(DEFINE)(?<element><[^m][^>]>[^<])(?<word>\w*+))/B
------------------------------------------------------------------ ------------------------------------------------------------------
@ -10401,8 +10397,7 @@ No match
/(?<=abc)def/ /(?<=abc)def/
abc\=ph abc\=ph
Partial match: abc Partial match:
<<<
/abc$/ /abc$/
abc abc
@ -11959,11 +11954,9 @@ Callout 2: last capture = 0
/(?<=123)(*MARK:xx)abc/mark /(?<=123)(*MARK:xx)abc/mark
xxxx123a\=ph xxxx123a\=ph
Partial match, mark=xx: 123a Partial match, mark=xx: a
<<<
xxxx123a\=ps xxxx123a\=ps
Partial match, mark=xx: 123a Partial match, mark=xx: a
<<<
/123\Kabc/startchar /123\Kabc/startchar
xxxx123a\=ph xxxx123a\=ph
@ -17045,8 +17038,7 @@ Max lookbehind = 2
First code unit = 'c' First code unit = 'c'
Subject length lower bound = 1 Subject length lower bound = 1
abc\=ph abc\=ph
Partial match: abc Partial match: c
<<
\= Expect no match \= Expect no match
xbc\=ph xbc\=ph
No match No match
@ -17057,8 +17049,7 @@ Max lookbehind = 2
First code unit = 'c' First code unit = 'c'
Subject length lower bound = 1 Subject length lower bound = 1
abc\=ph abc\=ph
Partial match: abc Partial match: c
<<
\= Expect no match \= Expect no match
xbc\=ph xbc\=ph
No match No match

14
testdata/testoutput6 vendored
View File

@ -876,7 +876,7 @@ Partial match: abc
0: def 0: def
/(?<=foo)bar/ /(?<=foo)bar/
foob\=ps,offset=2 foob\=ps,offset=2,allusedtext
Partial match: foob Partial match: foob
<<< <<<
foobar...\=ps,dfa_restart,offset=4 foobar...\=ps,dfa_restart,offset=4
@ -6803,9 +6803,10 @@ Partial match: dogs
xyzabc123pqr xyzabc123pqr
Failed: error -42: pattern contains an item that is not supported for DFA matching Failed: error -42: pattern contains an item that is not supported for DFA matching
/(?<=abc)123/ /(?<=abc)123/allusedtext
xyzabc123pqr xyzabc123pqr
0: 123 0: abc123
<<<
xyzabc12\=ps xyzabc12\=ps
Partial match: abc12 Partial match: abc12
<<< <<<
@ -6813,9 +6814,10 @@ Partial match: abc12
Partial match: abc12 Partial match: abc12
<<< <<<
/\babc\b/ /\babc\b/allusedtext
+++abc+++ +++abc+++
0: abc 0: +abc+
< >
+++ab\=ps +++ab\=ps
Partial match: +ab Partial match: +ab
< <
@ -6932,7 +6934,7 @@ Failed: error -42: pattern contains an item that is not supported for DFA matchi
ac ac
Failed: error -42: pattern contains an item that is not supported for DFA matching Failed: error -42: pattern contains an item that is not supported for DFA matching
/(?<=abc)def/ /(?<=abc)def/allusedtext
abc\=ph abc\=ph
Partial match: abc Partial match: abc
<<< <<<