Revision: 526
http://www.exim.org/viewvc/pcre2?view=rev&revision=526
Author: ph10
Date: 2016-06-17 12:30:27 +0100 (Fri, 17 Jun 2016)
Log Message:
-----------
Return an error code when pcre2_get_error_message() does not recognize an error
code, and add a pcre2test facility for testing this.
Modified Paths:
--------------
code/trunk/ChangeLog
code/trunk/RunTest
code/trunk/doc/html/pcre2_get_error_message.html
code/trunk/doc/html/pcre2api.html
code/trunk/doc/html/pcre2test.html
code/trunk/doc/pcre2.txt
code/trunk/doc/pcre2_get_error_message.3
code/trunk/doc/pcre2api.3
code/trunk/doc/pcre2test.1
code/trunk/doc/pcre2test.txt
code/trunk/src/pcre2_error.c
code/trunk/src/pcre2test.c
code/trunk/testdata/testoutput2
Modified: code/trunk/ChangeLog
===================================================================
--- code/trunk/ChangeLog 2016-06-14 16:14:52 UTC (rev 525)
+++ code/trunk/ChangeLog 2016-06-17 11:30:27 UTC (rev 526)
@@ -136,7 +136,14 @@
35. Fix potential negative index in pcre2test.
+36. Calls to pcre2_get_error_message() with error numbers that are never
+returned by PCRE2 functions were returning empty strings. Now the error code
+PCRE2_ERROR_BADDATA is returned. A facility has been added to pcre2test to
+show the texts for given error numbers (i.e. to call pcre2_get_error_message()
+and display what it returns) and a few representative error codes are now
+checked in RunTest.
+
Version 10.21 12-January-2016
-----------------------------
Modified: code/trunk/RunTest
===================================================================
--- code/trunk/RunTest 2016-06-14 16:14:52 UTC (rev 525)
+++ code/trunk/RunTest 2016-06-17 11:30:27 UTC (rev 526)
@@ -499,6 +499,7 @@
for opt in "" $jitopt; do
$sim $valgrind ${opt:+$vjs} ./pcre2test -q $test2stack $bmode $opt $testdata/testinput2 testtry
if [ $? = 0 ] ; then
+ $sim $valgrind ${opt:+$vjs} ./pcre2test -q $bmode $opt -error -63,-62,-2,-1,0,100,188,189 >>testtry
checkresult $? 2 "$opt"
else
echo " "
Modified: code/trunk/doc/html/pcre2_get_error_message.html
===================================================================
--- code/trunk/doc/html/pcre2_get_error_message.html 2016-06-14 16:14:52 UTC (rev 525)
+++ code/trunk/doc/html/pcre2_get_error_message.html 2016-06-17 11:30:27 UTC (rev 526)
@@ -35,7 +35,10 @@
<i>bufflen</i> the length of the buffer (code units)
</pre>
The function returns the length of the message, excluding the trailing zero, or
-a negative error code if the buffer is too small.
+the negative error code PCRE2_ERROR_NOMEMORY if the buffer is too small. In
+this case, the returned message is truncated (but still with a trailing zero).
+If <i>errorcode</i> does not contain a recognized error code number, the
+negative value PCRE2_ERROR_BADDATA is returned.
</P>
<P>
There is a complete description of the PCRE2 native API in the
Modified: code/trunk/doc/html/pcre2api.html
===================================================================
--- code/trunk/doc/html/pcre2api.html 2016-06-14 16:14:52 UTC (rev 525)
+++ code/trunk/doc/html/pcre2api.html 2016-06-17 11:30:27 UTC (rev 526)
@@ -43,16 +43,17 @@
<li><a name="TOC28" href="#SEC28">HOW PCRE2_MATCH() RETURNS A STRING AND CAPTURED SUBSTRINGS</a>
<li><a name="TOC29" href="#SEC29">OTHER INFORMATION ABOUT A MATCH</a>
<li><a name="TOC30" href="#SEC30">ERROR RETURNS FROM <b>pcre2_match()</b></a>
-<li><a name="TOC31" href="#SEC31">EXTRACTING CAPTURED SUBSTRINGS BY NUMBER</a>
-<li><a name="TOC32" href="#SEC32">EXTRACTING A LIST OF ALL CAPTURED SUBSTRINGS</a>
-<li><a name="TOC33" href="#SEC33">EXTRACTING CAPTURED SUBSTRINGS BY NAME</a>
-<li><a name="TOC34" href="#SEC34">CREATING A NEW STRING WITH SUBSTITUTIONS</a>
-<li><a name="TOC35" href="#SEC35">DUPLICATE SUBPATTERN NAMES</a>
-<li><a name="TOC36" href="#SEC36">FINDING ALL POSSIBLE MATCHES AT ONE POSITION</a>
-<li><a name="TOC37" href="#SEC37">MATCHING A PATTERN: THE ALTERNATIVE FUNCTION</a>
-<li><a name="TOC38" href="#SEC38">SEE ALSO</a>
-<li><a name="TOC39" href="#SEC39">AUTHOR</a>
-<li><a name="TOC40" href="#SEC40">REVISION</a>
+<li><a name="TOC31" href="#SEC31">OBTAINING A TEXTUAL ERROR MESSAGE</a>
+<li><a name="TOC32" href="#SEC32">EXTRACTING CAPTURED SUBSTRINGS BY NUMBER</a>
+<li><a name="TOC33" href="#SEC33">EXTRACTING A LIST OF ALL CAPTURED SUBSTRINGS</a>
+<li><a name="TOC34" href="#SEC34">EXTRACTING CAPTURED SUBSTRINGS BY NAME</a>
+<li><a name="TOC35" href="#SEC35">CREATING A NEW STRING WITH SUBSTITUTIONS</a>
+<li><a name="TOC36" href="#SEC36">DUPLICATE SUBPATTERN NAMES</a>
+<li><a name="TOC37" href="#SEC37">FINDING ALL POSSIBLE MATCHES AT ONE POSITION</a>
+<li><a name="TOC38" href="#SEC38">MATCHING A PATTERN: THE ALTERNATIVE FUNCTION</a>
+<li><a name="TOC39" href="#SEC39">SEE ALSO</a>
+<li><a name="TOC40" href="#SEC40">AUTHOR</a>
+<li><a name="TOC41" href="#SEC41">REVISION</a>
</ul>
<P>
<b>#include <pcre2.h></b>
@@ -1063,7 +1064,7 @@
The pattern is defined by a pointer to a string of code units and a length. If
the pattern is zero-terminated, the length can be specified as
PCRE2_ZERO_TERMINATED. The function returns a pointer to a block of memory that
-contains the compiled pattern and related data.
+contains the compiled pattern and related data, or NULL if an error occurred.
</P>
<P>
If the compile context argument <i>ccontext</i> is NULL, memory for the compiled
@@ -1085,8 +1086,9 @@
<P>
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
-be referenced by the extraction functions. After running a match, you must not
-free a compiled pattern (or a subject string) until after all operations on the
+be referenced by the substring extraction functions. After running a match, you
+must not free a compiled pattern (or a subject string) until after all
+operations on the
<a href="#matchdatablock">match data block</a>
have taken place.
</P>
@@ -1113,15 +1115,22 @@
</P>
<P>
If <i>errorcode</i> or <i>erroroffset</i> is NULL, <b>pcre2_compile()</b> returns
-NULL immediately. Otherwise, if compilation of a pattern fails,
-<b>pcre2_compile()</b> returns NULL, having set these variables to an error code
-and an offset (number of code units) within the pattern, respectively. The
-<b>pcre2_get_error_message()</b> function provides a textual message for each
-error code. Compilation errors are positive numbers, but UTF formatting errors
-are negative numbers. For an invalid UTF-8 or UTF-16 string, the offset is that
-of the first code unit of the failing character.
+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 <b>pcre2_compile()</b> returns NULL because a compilation
+error has occurred. The values are not defined when compilation is successful
+and <b>pcre2_compile()</b> returns a non-NULL value.
</P>
<P>
+The <b>pcre2_get_error_message()</b> function (see "Obtaining a textual error
+message"
+<a href="#geterrormessage">below)</a>
+provides a textual message for each error code. Compilation errors have
+positive error codes; UTF formatting error codes are negative. For an invalid
+UTF-8 or UTF-16 string, the offset is that of the first code unit of the
+failing character.
+</P>
+<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
@@ -1488,13 +1497,16 @@
</P>
<br><a name="SEC19" href="#TOC1">COMPILATION ERROR CODES</a><br>
<P>
-There are over 80 positive error codes that <b>pcre2_compile()</b> may return if
-it finds an error in the pattern. There are also some negative error codes that
-are used for invalid UTF strings. These are the same as given by
-<b>pcre2_match()</b> and <b>pcre2_dfa_match()</b>, and are described in the
+There are over 80 positive error codes that <b>pcre2_compile()</b> may return
+(via <i>errorcode</i>) if it finds an error in the pattern. There are also some
+negative error codes that are used for invalid UTF strings. These are the same
+as given by <b>pcre2_match()</b> and <b>pcre2_dfa_match()</b>, and are described
+in the
<a href="pcre2unicode.html"><b>pcre2unicode</b></a>
-page. The <b>pcre2_get_error_message()</b> function can be called to obtain a
-textual error message from any error code.
+page. The <b>pcre2_get_error_message()</b> function (see "Obtaining a textual
+error message"
+<a href="#geterrormessage">below)</a>
+can be called to obtain a textual error message from any error code.
<a name="jitcompiling"></a></P>
<br><a name="SEC20" href="#TOC1">JUST-IN-TIME (JIT) COMPILATION</a><br>
<P>
@@ -2416,11 +2428,13 @@
<br><a name="SEC30" href="#TOC1">ERROR RETURNS FROM <b>pcre2_match()</b></a><br>
<P>
If <b>pcre2_match()</b> fails, it returns a negative number. This can be
-converted to a text string by calling <b>pcre2_get_error_message()</b>. 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
+converted to a text string by calling the <b>pcre2_get_error_message()</b>
+function (see "Obtaining a textual error message"
+<a href="#geterrormessage">below).</a>
+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
<a href="pcre2unicode.html"><b>pcre2unicode</b></a>
page. The following are the other errors that may be returned by
<b>pcre2_match()</b>:
@@ -2521,8 +2535,29 @@
PCRE2_ERROR_RECURSIONLIMIT
</pre>
The internal recursion limit was reached.
+<a name="geterrormessage"></a></P>
+<br><a name="SEC31" href="#TOC1">OBTAINING A TEXTUAL ERROR MESSAGE</a><br>
+<P>
+<b>int pcre2_get_error_message(int <i>errorcode</i>, PCRE2_UCHAR *<i>buffer</i>,</b>
+<b> PCRE2_SIZE <i>bufflen</i>);</b>
+</P>
+<P>
+A text message for an error code from any PCRE2 function (compile, match, or
+auxiliary) can be obtained by calling <b>pcre2_get_error_message()</b>. The code
+is passed as the first argument, with the remaining two arguments specifying a
+code unit buffer and its length, into which the text message is placed. Note
+that the message is returned in code units of the appropriate width for the
+library that is being used.
+</P>
+<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.
<a name="extractbynumber"></a></P>
-<br><a name="SEC31" href="#TOC1">EXTRACTING CAPTURED SUBSTRINGS BY NUMBER</a><br>
+<br><a name="SEC32" href="#TOC1">EXTRACTING CAPTURED SUBSTRINGS BY NUMBER</a><br>
<P>
<b>int pcre2_substring_length_bynumber(pcre2_match_data *<i>match_data</i>,</b>
<b> uint32_t <i>number</i>, PCRE2_SIZE *<i>length</i>);</b>
@@ -2619,7 +2654,7 @@
(abc)|(def) and the subject is "def", and the ovector contains at least two
capturing slots, substring number 1 is unset.
</P>
-<br><a name="SEC32" href="#TOC1">EXTRACTING A LIST OF ALL CAPTURED SUBSTRINGS</a><br>
+<br><a name="SEC33" href="#TOC1">EXTRACTING A LIST OF ALL CAPTURED SUBSTRINGS</a><br>
<P>
<b>int pcre2_substring_list_get(pcre2_match_data *<i>match_data</i>,</b>
<b>" PCRE2_UCHAR ***<i>listptr</i>, PCRE2_SIZE **<i>lengthsptr</i>);</b>
@@ -2658,7 +2693,7 @@
appropriate offset in the ovector, which contain PCRE2_UNSET for unset
substrings, or by calling <b>pcre2_substring_length_bynumber()</b>.
<a name="extractbyname"></a></P>
-<br><a name="SEC33" href="#TOC1">EXTRACTING CAPTURED SUBSTRINGS BY NAME</a><br>
+<br><a name="SEC34" href="#TOC1">EXTRACTING CAPTURED SUBSTRINGS BY NAME</a><br>
<P>
<b>int pcre2_substring_number_from_name(const pcre2_code *<i>code</i>,</b>
<b> PCRE2_SPTR <i>name</i>);</b>
@@ -2718,7 +2753,7 @@
numbers. For this reason, the use of different names for subpatterns of the
same number causes an error at compile time.
</P>
-<br><a name="SEC34" href="#TOC1">CREATING A NEW STRING WITH SUBSTITUTIONS</a><br>
+<br><a name="SEC35" href="#TOC1">CREATING A NEW STRING WITH SUBSTITUTIONS</a><br>
<P>
<b>int pcre2_substitute(const pcre2_code *<i>code</i>, PCRE2_SPTR <i>subject</i>,</b>
<b> PCRE2_SIZE <i>length</i>, PCRE2_SIZE <i>startoffset</i>,</b>
@@ -2921,9 +2956,11 @@
</P>
<P>
As for all PCRE2 errors, a text message that describes the error can be
-obtained by calling <b>pcre2_get_error_message()</b>.
+obtained by calling the <b>pcre2_get_error_message()</b> function (see
+"Obtaining a textual error message"
+<a href="#geterrormessage">above).</a>
</P>
-<br><a name="SEC35" href="#TOC1">DUPLICATE SUBPATTERN NAMES</a><br>
+<br><a name="SEC36" href="#TOC1">DUPLICATE SUBPATTERN NAMES</a><br>
<P>
<b>int pcre2_substring_nametable_scan(const pcre2_code *<i>code</i>,</b>
<b> PCRE2_SPTR <i>name</i>, PCRE2_SPTR *<i>first</i>, PCRE2_SPTR *<i>last</i>);</b>
@@ -2968,7 +3005,7 @@
relevant entries for the name, you can extract each of their numbers, and hence
the captured data.
</P>
-<br><a name="SEC36" href="#TOC1">FINDING ALL POSSIBLE MATCHES AT ONE POSITION</a><br>
+<br><a name="SEC37" href="#TOC1">FINDING ALL POSSIBLE MATCHES AT ONE POSITION</a><br>
<P>
The traditional matching function uses a similar algorithm to Perl, which stops
when it finds the first match at a given point in the subject. If you want to
@@ -2986,7 +3023,7 @@
other alternatives. Ultimately, when it runs out of matches,
<b>pcre2_match()</b> will yield PCRE2_ERROR_NOMATCH.
<a name="dfamatch"></a></P>
-<br><a name="SEC37" href="#TOC1">MATCHING A PATTERN: THE ALTERNATIVE FUNCTION</a><br>
+<br><a name="SEC38" href="#TOC1">MATCHING A PATTERN: THE ALTERNATIVE FUNCTION</a><br>
<P>
<b>int pcre2_dfa_match(const pcre2_code *<i>code</i>, PCRE2_SPTR <i>subject</i>,</b>
<b> PCRE2_SIZE <i>length</i>, PCRE2_SIZE <i>startoffset</i>,</b>
@@ -3181,13 +3218,13 @@
should contain data about the previous partial match. If any of these checks
fail, this error is given.
</P>
-<br><a name="SEC38" href="#TOC1">SEE ALSO</a><br>
+<br><a name="SEC39" href="#TOC1">SEE ALSO</a><br>
<P>
<b>pcre2build</b>(3), <b>pcre2callout</b>(3), <b>pcre2demo(3)</b>,
<b>pcre2matching</b>(3), <b>pcre2partial</b>(3), <b>pcre2posix</b>(3),
<b>pcre2sample</b>(3), <b>pcre2stack</b>(3), <b>pcre2unicode</b>(3).
</P>
-<br><a name="SEC39" href="#TOC1">AUTHOR</a><br>
+<br><a name="SEC40" href="#TOC1">AUTHOR</a><br>
<P>
Philip Hazel
<br>
@@ -3196,9 +3233,9 @@
Cambridge, England.
<br>
</P>
-<br><a name="SEC40" href="#TOC1">REVISION</a><br>
+<br><a name="SEC41" href="#TOC1">REVISION</a><br>
<P>
-Last updated: 05 June 2016
+Last updated: 17 June 2016
<br>
Copyright © 1997-2016 University of Cambridge.
<br>
Modified: code/trunk/doc/html/pcre2test.html
===================================================================
--- code/trunk/doc/html/pcre2test.html 2016-06-14 16:14:52 UTC (rev 525)
+++ code/trunk/doc/html/pcre2test.html 2016-06-17 11:30:27 UTC (rev 526)
@@ -98,7 +98,7 @@
</P>
<P>
For maximum portability, therefore, it is safest to avoid non-printing
-characters in <b>pcre2test</b> input files. There is a facility for specifying
+characters in <b>pcre2test</b> input files. There is a facility for specifying
some or all of a pattern's characters as hexadecimal pairs, thus making it
possible to include binary zeroes in a pattern for testing purposes. Subject
lines are processed for backslash escapes, which makes it possible to include
@@ -179,6 +179,13 @@
<b>pcre2_match()</b>.
</P>
<P>
+<b>-error</b> <i>number[,number,...]</i>
+Call <b>pcre2_get_error_message()</b> for each of the error numbers in the
+comma-separated list, display the resulting messages on the standard output,
+then exit with zero exit code. The numbers may be positive or negative. This is
+a convenience facility for PCRE2 maintainers.
+</P>
+<P>
<b>-help</b>
Output a brief summary these options and then exit.
</P>
@@ -572,7 +579,7 @@
null_context compile with a NULL context
parens_nest_limit=<n> set maximum parentheses depth
posix use the POSIX API
- posix_nosub use the POSIX API with REG_NOSUB
+ posix_nosub use the POSIX API with REG_NOSUB
push push compiled pattern onto the stack
pushcopy push a copy onto the stack
stackguard=<number> test the stackguard feature
@@ -662,22 +669,22 @@
Specifying pattern characters in hexadecimal
</b><br>
<P>
-The <b>hex</b> modifier specifies that the characters of the pattern, except for
+The <b>hex</b> modifier specifies that the characters of the pattern, except for
substrings enclosed in single or double quotes, are to be interpreted as pairs
of hexadecimal digits. This feature is provided as a way of creating patterns
that contain binary zeros and other non-printing characters. White space is
-permitted between pairs of digits. For example, this pattern contains three
+permitted between pairs of digits. For example, this pattern contains three
characters:
<pre>
/ab 32 59/hex
</pre>
-Parts of such a pattern are taken literally if quoted. This pattern contains
+Parts of such a pattern are taken literally if quoted. This pattern contains
nine characters, only two of which are specified in hexadecimal:
<pre>
/ab "literal" 32/hex
</pre>
Either single or double quotes may be used. There is no way of including
-the delimiter within a substring.
+the delimiter within a substring.
</P>
<P>
By default, <b>pcre2test</b> passes patterns as zero-terminated strings to
@@ -935,8 +942,8 @@
facility is used when saving compiled patterns to a file, as described in the
section entitled "Saving and restoring compiled patterns"
<a href="#saverestore">below. If <b>pushcopy</b> is used instead of <b>push</b>, a copy of the compiled</a>
-pattern is stacked, leaving the original as current, ready to match the
-following input lines. This provides a way of testing the
+pattern is stacked, leaving the original as current, ready to match the
+following input lines. This provides a way of testing the
<b>pcre2_code_copy()</b> function.
The <b>push</b> and <b>pushcopy </b> modifiers are incompatible with compilation
modifiers such as <b>global</b> that act at match time. Any that are specified
@@ -962,7 +969,7 @@
anchored set PCRE2_ANCHORED
dfa_restart set PCRE2_DFA_RESTART
dfa_shortest set PCRE2_DFA_SHORTEST
- no_jit set PCRE2_NO_JIT
+ no_jit set PCRE2_NO_JIT
no_utf_check set PCRE2_NO_UTF_CHECK
notbol set PCRE2_NOTBOL
notempty set PCRE2_NOTEMPTY
@@ -1023,7 +1030,7 @@
substitute_unset_empty use PCRE2_SUBSTITUTE_UNSET_EMPTY
zero_terminate pass the subject as zero-terminated
</pre>
-The effects of these modifiers are described in the following sections. When
+The effects of these modifiers are described in the following sections. When
matching via the POSIX wrapper API, the <b>aftertext</b>, <b>allaftertext</b>,
and <b>ovector</b> subject modifiers work as described below. All other
modifiers are either ignored, with a warning message, or cause an error.
@@ -1537,8 +1544,8 @@
This output indicates that callout number 0 occurred for a match attempt
starting at the fourth character of the subject string, when the pointer was at
the seventh character, and when the next pattern item was \d. Just
-one circumflex is output if the start and current positions are the same, or if
-the current position precedes the start position, which can happen if the
+one circumflex is output if the start and current positions are the same, or if
+the current position precedes the start position, which can happen if the
callout is in a lookbehind assertion.
</P>
<P>
@@ -1636,7 +1643,7 @@
stacked, leaving the original available for immediate matching. By using
<b>push</b> and/or <b>pushcopy</b>, a number of patterns can be compiled and
retained. These modifiers are incompatible with <b>posix</b>, and control
-modifiers that act at match time are ignored (with a message) for the stacked
+modifiers that act at match time are ignored (with a message) for the stacked
patterns. The <b>jitverify</b> modifier applies only at compile time.
</P>
<P>
@@ -1677,8 +1684,8 @@
<b>jit</b>, which is different behaviour from when it is used on a pattern.
</P>
<P>
-The #popcopy command is analagous to the <b>pushcopy</b> modifier in that it
-makes current a copy of the topmost stack pattern, leaving the original still
+The #popcopy command is analagous to the <b>pushcopy</b> modifier in that it
+makes current a copy of the topmost stack pattern, leaving the original still
on the stack.
</P>
<br><a name="SEC19" href="#TOC1">SEE ALSO</a><br>
@@ -1698,7 +1705,7 @@
</P>
<br><a name="SEC21" href="#TOC1">REVISION</a><br>
<P>
-Last updated: 05 June 2016
+Last updated: 17 June 2016
<br>
Copyright © 1997-2016 University of Cambridge.
<br>
Modified: code/trunk/doc/pcre2.txt
===================================================================
--- code/trunk/doc/pcre2.txt 2016-06-14 16:14:52 UTC (rev 525)
+++ code/trunk/doc/pcre2.txt 2016-06-17 11:30:27 UTC (rev 526)
@@ -1106,63 +1106,68 @@
The pattern is defined by a pointer to a string of code units and a
length. If the pattern is zero-terminated, the length can be specified
as PCRE2_ZERO_TERMINATED. The function returns a pointer to a block of
- memory that contains the compiled pattern and related data.
+ memory that contains the compiled pattern and related data, or NULL if
+ an error occurred.
- If the compile context argument ccontext is NULL, memory for the com-
- piled pattern is obtained by calling malloc(). Otherwise, it is
- obtained from the same memory function that was used for the compile
- context. The caller must free the memory by calling pcre2_code_free()
+ If the compile context argument ccontext is NULL, memory for the com-
+ piled pattern is obtained by calling malloc(). Otherwise, it is
+ obtained from the same memory function that was used for the compile
+ context. The caller must free the memory by calling pcre2_code_free()
when it is no longer needed.
The function pcre2_code_copy() makes a copy of the compiled code in new
- memory, using the same memory allocator as was used for the original.
- However, if the code has been processed by the JIT compiler (see
- below), the JIT information cannot be copied (because it is position-
+ memory, using the same memory allocator as was used for the original.
+ However, if the code has been processed by the JIT compiler (see
+ below), the JIT information cannot be copied (because it is position-
dependent). The new copy can initially be used only for non-JIT match-
- ing, though it can be passed to pcre2_jit_compile() if required. The
- pcre2_code_copy() function provides a way for individual threads in a
- multithreaded application to acquire a private copy of shared compiled
+ ing, though it can be passed to pcre2_jit_compile() if required. The
+ pcre2_code_copy() function provides a way for individual threads in a
+ multithreaded application to acquire a private copy of shared compiled
code.
- NOTE: When one of the matching functions is called, pointers to the
+ 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 be referenced by the extraction functions. After run-
- ning a match, you must not free a compiled pattern (or a subject
- string) until after all operations on the match data block have taken
- place.
+ so that they can be referenced by the substring extraction functions.
+ After running a match, you must not free a compiled pattern (or a sub-
+ ject string) until after all operations on the match data block have
+ taken place.
- The options argument for pcre2_compile() contains various bit settings
- that affect the compilation. It should be zero if no options are
- 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
+ The options argument for pcre2_compile() contains various bit settings
+ that affect the compilation. It should be zero if no options are
+ 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 pcre2pattern documentation).
- For those options that can be different in different parts of the pat-
- tern, the contents of the options argument specifies their settings at
- the start of compilation. The PCRE2_ANCHORED and PCRE2_NO_UTF_CHECK
+ For those options that can be different in different parts of the pat-
+ tern, the contents of the options argument specifies their settings at
+ the start of compilation. The PCRE2_ANCHORED and PCRE2_NO_UTF_CHECK
options can be set at the time of matching as well as at compile time.
- Other, less frequently required compile-time parameters (for example,
+ Other, less frequently required compile-time parameters (for example,
the newline setting) can be provided in a compile context (as described
above).
If errorcode or erroroffset is NULL, pcre2_compile() returns NULL imme-
- diately. Otherwise, if compilation of a pattern fails, pcre2_compile()
- returns NULL, having set these variables to an error code and an offset
- (number of code units) within the pattern, respectively. The
- pcre2_get_error_message() function provides a textual message for each
- error code. Compilation errors are positive numbers, but UTF formatting
- errors are negative numbers. For an invalid UTF-8 or UTF-16 string, the
- offset is that of the first code unit of the failing character.
+ diately. 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 pcre2_compile() returns NULL because a compilation
+ error has occurred. The values are not defined when compilation is suc-
+ cessful and pcre2_compile() returns a non-NULL value.
- 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
+ The pcre2_get_error_message() function (see "Obtaining a textual error
+ message" below) provides a textual message for each error code. Compi-
+ lation errors have positive error codes; UTF formatting error codes are
+ negative. For an invalid UTF-8 or UTF-16 string, the offset is that of
+ the first code unit of the failing character.
+
+ 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 char-
acter.
- This code fragment shows a typical straightforward call to pcre2_com-
+ This code fragment shows a typical straightforward call to pcre2_com-
pile():
pcre2_code *re;
@@ -1176,28 +1181,28 @@
&erroffset, /* for error offset */
NULL); /* no compile context */
- The following names for option bits are defined in the pcre2.h header
+ The following names for option bits are defined in the pcre2.h header
file:
PCRE2_ANCHORED
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
+ 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.
PCRE2_ALLOW_EMPTY_CLASS
- 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
+ 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.
PCRE2_ALT_BSUX
- This option request alternative handling of three escape sequences,
- which makes PCRE2's behaviour more like ECMAscript (aka JavaScript).
+ This option request alternative handling of three escape sequences,
+ which makes PCRE2's behaviour more like ECMAscript (aka JavaScript).
When it is set:
(1) \U matches an upper case "U" character; by default \U causes a com-
@@ -1204,13 +1209,13 @@
pile time error (Perl uses \U to upper case subsequent characters).
(2) \u 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, \u causes a compile time error (Perl
+ hexadecimal digits, in which case the hexadecimal number defines the
+ code point to match. By default, \u causes a compile time error (Perl
uses it to upper case the following character).
- (3) \x 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
+ (3) \x 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 \x, but it may have zero, one, or two digits (so,
for example, \xz matches a binary zero character followed by z).
@@ -1217,53 +1222,53 @@
PCRE2_ALT_CIRCUMFLEX
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
+ 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 termi-
+ Perl. If you want a multiline circumflex also to match after a termi-
nating newline, you must set PCRE2_ALT_CIRCUMFLEX.
PCRE2_ALT_VERBNAMES
- 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 unescaped closing
- parenthesis terminates the name. A closing parenthesis can be included
- in a name either as \) or between \Q and \E. If the PCRE2_EXTENDED
+ 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 unescaped closing
+ parenthesis terminates the name. A closing parenthesis can be included
+ in a name either as \) or between \Q and \E. If the PCRE2_EXTENDED
option is set, unescaped whitespace in verb names is skipped and #-com-
ments are recognized, exactly as in the rest of the pattern.
PCRE2_AUTO_CALLOUT
- If this bit is set, pcre2_compile() automatically inserts callout
+ If this bit is set, pcre2_compile() automatically inserts callout
items, all with number 255, before each pattern item. For discussion of
the callout facility, see the pcre2callout documentation.
PCRE2_CASELESS
- 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
+ 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 changed within a pattern by a (?i) option setting.
PCRE2_DOLLAR_ENDONLY
- 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
+ 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.
PCRE2_DOTALL
- If this bit is set, a dot metacharacter in the pattern matches any
- character, including one that indicates a newline. However, it only
+ 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 sub-
- ject is at a newline. This option is equivalent to Perl's /s option,
+ ject 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 neg-
ative class such as [^a] always matches newline characters, independent
of the setting of this option.
@@ -1270,181 +1275,181 @@
PCRE2_DUPNAMES
- If this bit is set, names used to identify capturing subpatterns need
+ If this bit is set, names used to identify capturing subpatterns need
not be unique. This can be helpful for certain types of pattern when it
- is known that only one instance of the named subpattern can ever be
- matched. There are more details of named subpatterns below; see also
+ is known that only one instance of the named subpattern can ever be
+ matched. There are more details of named subpatterns below; see also
the pcre2pattern documentation.
PCRE2_EXTENDED
- If this bit is set, most white space characters in the pattern are
- totally ignored except when escaped or inside a character class. How-
- ever, white space is not allowed within sequences such as (?> that
+ If this bit is set, most white space characters in the pattern are
+ totally ignored except when escaped or inside a character class. How-
+ ever, white space is not allowed within sequences such as (?> that
introduce various parenthesized subpatterns, nor within numerical quan-
- tifiers such as {1,3}. Ignorable white space is permitted between an
- item and a following quantifier and between a quantifier and a follow-
+ tifiers such as {1,3}. Ignorable white space is permitted between an
+ item and a following quantifier and between a quantifier and a follow-
ing + that indicates possessiveness.
- PCRE2_EXTENDED also causes characters between an unescaped # outside a
- character class and the next newline, inclusive, to be ignored, which
+ 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
+ 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. PCRE2_EXTENDED is equivalent to Perl's /x option, and it can be
+ count. PCRE2_EXTENDED is equivalent to Perl's /x option, and it can be
changed within a pattern by a (?x) option setting.
Which characters are interpreted as newlines can be specified by a set-
- ting in the compile context that is passed to pcre2_compile() or by a
- special sequence at the start of the pattern, as described in the sec-
- tion entitled "Newline conventions" in the pcre2pattern documentation.
+ ting in the compile context that is passed to pcre2_compile() or by a
+ special sequence at the start of the pattern, as described in the sec-
+ tion entitled "Newline conventions" in the pcre2pattern documentation.
A default is defined when PCRE2 is built.
PCRE2_FIRSTLINE
- If this option is set, an unanchored pattern is required to match
- before or at the first newline in the subject string, though the
- matched text may continue over the newline. See also PCRE2_USE_OFF-
- SET_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
+ If this option is set, an unanchored pattern is required to match
+ before or at the first newline in the subject string, though the
+ matched text may continue over the newline. See also PCRE2_USE_OFF-
+ SET_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.
PCRE2_MATCH_UNSET_BACKREF
- If this option is set, a back reference to an unset subpattern group
- matches an empty string (by default this causes the current matching
- alternative to fail). A pattern such as (\1)(a) succeeds when this
- option is set (assuming it can find an "a" in the subject), whereas it
- fails by default, for Perl compatibility. Setting this option makes
+ If this option is set, a back reference to an unset subpattern group
+ matches an empty string (by default this causes the current matching
+ alternative to fail). A pattern such as (\1)(a) succeeds when this
+ option is set (assuming it can find an "a" in the subject), whereas it
+ fails by default, for Perl compatibility. Setting this option makes
PCRE2 behave more like ECMAscript (aka JavaScript).
PCRE2_MULTILINE
- 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 ($) matches only at the end of the
+ By default, for the purposes of matching "start of line" and "end of
+ line", PCRE2 treats the subject string as consisting of a single line
+ of characters, even if it actually contains newlines. The "start of
+ line" metacharacter (^) matches only at the start of the string, and
+ the "end of line" metacharacter ($) matches only at the end of the
string, or before a terminating newline (except when PCRE2_DOL-
- LAR_ENDONLY is set). Note, however, that unless PCRE2_DOTALL is set,
+ LAR_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.
- 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
+ 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 (?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
+ 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.
PCRE2_NEVER_BACKSLASH_C
- This option locks out the use of \C in the pattern that is being com-
- piled. 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 external sources. Note that
+ This option locks out the use of \C in the pattern that is being com-
+ piled. 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 external sources. Note that
there is also a build-time option that permanently locks out the use of
\C.
PCRE2_NEVER_UCP
- This option locks out the use of Unicode properties for handling \B,
+ This option locks out the use of Unicode properties for handling \B,
\b, \D, \d, \S, \s, \W, \w, 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 option may be useful in applications that
+ 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 option may be useful in applications that
process patterns from external sources. The option combination PCRE_UCP
and PCRE_NEVER_UCP causes an error.
PCRE2_NEVER_UTF
- This option locks out interpretation of the pattern as UTF-8, UTF-16,
+ 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 pre-
- vents the creator of the pattern from switching to UTF interpretation
- by starting the pattern with (*UTF). This option may be useful in
- applications that process patterns from external sources. The combina-
+ vents the creator of the pattern from switching to UTF interpretation
+ by starting the pattern with (*UTF). This option may be useful in
+ applications that process patterns from external sources. The combina-
tion of PCRE2_UTF and PCRE2_NEVER_UTF causes an error.
PCRE2_NO_AUTO_CAPTURE
If this option is set, it disables the use of numbered capturing paren-
- theses 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 they acquire numbers in the usual way).
- There is no equivalent of this option in Perl. Note that, if this
- option is set, references to capturing groups (back references or
- recursion/subroutine calls) may only refer to named groups, though the
+ theses 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 they acquire numbers in the usual way).
+ There is no equivalent of this option in Perl. Note that, if this
+ option is set, references to capturing groups (back references or
+ recursion/subroutine calls) may only refer to named groups, though the
reference can be by name or by number.
PCRE2_NO_AUTO_POSSESS
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
+ 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
+ a full unoptimized search and run all the callouts, but it is mainly
provided for testing purposes.
PCRE2_NO_DOTSTAR_ANCHOR
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 \A or \G or ^.
- The optimization is automatically disabled for .* if it is inside an
- atomic group or a capturing group that is the subject of a back refer-
- ence, or if the pattern contains (*PRUNE) or (*SKIP). When the opti-
- mization is not disabled, such a pattern is automatically anchored if
+ .* is the first significant item in a top-level branch of a pattern,
+ and all the other branches also start with .* or with \A or \G or ^.
+ The optimization is automatically disabled for .* if it is inside an
+ atomic group or a capturing group that is the subject of a back refer-
+ ence, or if the pattern contains (*PRUNE) or (*SKIP). When the opti-
+ mization 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
+ 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.
PCRE2_NO_START_OPTIMIZE
- This is an option whose main effect is at matching time. It does not
+ This is an option whose main effect is at matching time. It does not
change what pcre2_compile() generates, but it does affect the output of
the JIT compiler.
- 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 match must start with a specific character, the
- matching code searches the subject for that character, and fails imme-
- diately if it cannot find it, without actually running the main match-
- ing 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 optimiza-
- tions are in effect a pre-scan of the subject that takes place before
+ 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 match must start with a specific character, the
+ matching code searches the subject for that character, and fails imme-
+ diately if it cannot find it, without actually running the main match-
+ ing 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 optimiza-
+ tions are in effect a pre-scan of the subject that takes place before
the pattern is run.
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
+ 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.
- Setting PCRE2_NO_START_OPTIMIZE may change the outcome of a matching
+ Setting PCRE2_NO_START_OPTIMIZE may change the outcome of a matching
operation. Consider the pattern
(*COMMIT)ABC
- 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 pat-
- tern 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 the overall
+ 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 pat-
+ tern 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 the overall
result is "no match". There are also other start-up optimizations. For
example, a minimum length for the subject may be recorded. Consider the
pattern
@@ -1451,75 +1456,76 @@
(*MARK:A)(X|Y)
- The minimum length for a match is one character. If the subject is
+ The minimum length for a match is one character. If the subject is
"ABC", there will be attempts to match "ABC", "BC", and "C". An attempt
to match an empty string at the end of the subject does not take place,
- because PCRE2 knows that the subject is now too short, and so the
- (*MARK) is never encountered. In this case, the optimization does not
+ because PCRE2 knows that the subject is now too short, and so the
+ (*MARK) is never encountered. In this case, the optimization does not
affect the overall match result, which is still "no match", but it does
affect the auxiliary information that is returned.
PCRE2_NO_UTF_CHECK
- When PCRE2_UTF is set, the validity of the pattern as a UTF string is
- automatically checked. There are discussions about the validity of
- UTF-8 strings, UTF-16 strings, and UTF-32 strings in the pcre2unicode
+ When PCRE2_UTF is set, the validity of the pattern as a UTF string is
+ automatically checked. There are discussions about the validity of
+ UTF-8 strings, UTF-16 strings, and UTF-32 strings in the pcre2unicode
document. If an invalid UTF sequence is found, pcre2_compile() returns
a negative error code.
If you know that your pattern is valid, 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 pat-
- tern is undefined. It may cause your program to crash or loop. Note
- that this option can also be passed to pcre2_match() and
+ 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 pat-
+ tern is undefined. It may cause your program to crash or loop. Note
+ that this option can also be passed to pcre2_match() and
pcre_dfa_match(), to suppress validity checking of the subject string.
PCRE2_UCP
This option changes the way PCRE2 processes \B, \b, \D, \d, \S, \s, \W,
- \w, 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
+ \w, 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 generic character types in the pcre2pattern page. If you set
- PCRE2_UCP, matching one of the items it affects takes much longer. The
- option is available only if PCRE2 has been compiled with Unicode sup-
+ PCRE2_UCP, matching one of the items it affects takes much longer. The
+ option is available only if PCRE2 has been compiled with Unicode sup-
port.
PCRE2_UNGREEDY
- 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
+ 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.
PCRE2_USE_OFFSET_LIMIT
This option must be set for pcre2_compile() if pcre2_set_offset_limit()
- is going to be used to set a non-default offset limit in a match con-
- text 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 pcre2_set_offset_limit() in the section that describes
+ is going to be used to set a non-default offset limit in a match con-
+ text 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 pcre2_set_offset_limit() in the section that describes
match contexts. See also the PCRE2_FIRSTLINE option above.
PCRE2_UTF
- This option causes PCRE2 to regard both the pattern and the subject
- strings that are subsequently processed as strings of UTF characters
- instead of 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, the use of this option provokes an error.
- Details of how this option changes the behaviour of PCRE2 are given in
+ This option causes PCRE2 to regard both the pattern and the subject
+ strings that are subsequently processed as strings of UTF characters
+ instead of 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, the use of this option provokes an error.
+ Details of how this option changes the behaviour of PCRE2 are given in
the pcre2unicode page.
COMPILATION ERROR CODES
- There are over 80 positive error codes that pcre2_compile() may return
- if it finds an error in the pattern. There are also some negative error
- codes that are used for invalid UTF strings. These are the same as
- given by pcre2_match() and pcre2_dfa_match(), and are described in the
- pcre2unicode page. The pcre2_get_error_message() function can be called
- to obtain a textual error message from any error code.
+ There are over 80 positive error codes that pcre2_compile() may return
+ (via errorcode) if it finds an error in the pattern. There are also
+ some negative error codes that are used for invalid UTF strings. These
+ are the same as given by pcre2_match() and pcre2_dfa_match(), and are
+ described in the pcre2unicode page. The pcre2_get_error_message() func-
+ tion (see "Obtaining a textual error message" below) can be called to
+ obtain a textual error message from any error code.
JUST-IN-TIME (JIT) COMPILATION
@@ -2389,13 +2395,14 @@
ERROR RETURNS FROM pcre2_match()
If pcre2_match() fails, it returns a negative number. This can be con-
- verted to a text string by calling pcre2_get_error_message(). 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 check-
- ing 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 pcre2unicode page. The following are the other errors that
- may be returned by pcre2_match():
+ verted to a text string by calling the pcre2_get_error_message() func-
+ tion (see "Obtaining a textual error message" 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 pcre2unicode page. The following are the other errors that may be
+ returned by pcre2_match():
PCRE2_ERROR_NOMATCH
@@ -2403,19 +2410,19 @@
PCRE2_ERROR_PARTIAL
- The subject string did not match, but it did match partially. See the
+ The subject string did not match, but it did match partially. See the
pcre2partial documentation for details of partial matching.
PCRE2_ERROR_BADMAGIC
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
+ 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.
PCRE2_ERROR_BADMODE
- This error is given when a pattern that was compiled by the 8-bit
- library is passed to a 16-bit or 32-bit library function, or vice
+ This error is given when a pattern that was compiled by the 8-bit
+ library is passed to a 16-bit or 32-bit library function, or vice
versa.
PCRE2_ERROR_BADOFFSET
@@ -2429,35 +2436,35 @@
PCRE2_ERROR_BADUTFOFFSET
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 startoffset did not point to the beginning of a UTF character
+ found to be valid (the PCRE2_NO_UTF_CHECK option was not set), but the
+ value of startoffset did not point to the beginning of a UTF character
or the end of the subject.
PCRE2_ERROR_CALLOUT
- This error is never generated by pcre2_match() itself. It is provided
- for use by callout functions that want to cause pcre2_match() or
- pcre2_callout_enumerate() to return a distinctive error code. See the
+ This error is never generated by pcre2_match() itself. It is provided
+ for use by callout functions that want to cause pcre2_match() or
+ pcre2_callout_enumerate() to return a distinctive error code. See the
pcre2callout documentation for details.
PCRE2_ERROR_INTERNAL
- An unexpected internal error has occurred. This error could be caused
+ An unexpected internal error has occurred. This error could be caused
by a bug in PCRE2 or by overwriting of the compiled pattern.
PCRE2_ERROR_JIT_BADOPTION
- This error is returned when a pattern that was successfully studied
- using JIT is being matched, but the matching mode (partial or complete
- match) does not correspond to any JIT compilation mode. When the JIT
- fast path function is used, this error may be also given for invalid
+ This error is returned when a pattern that was successfully studied
+ using JIT is being matched, but the matching mode (partial or complete
+ match) does not correspond to any JIT compilation mode. When the JIT
+ fast path function is used, this error may be also given for invalid
options. See the pcre2jit documentation for more details.
PCRE2_ERROR_JIT_STACKLIMIT
- 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 pcre2jit documenta-
+ 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 pcre2jit documenta-
tion for more details.
PCRE2_ERROR_MATCHLIMIT
@@ -2466,10 +2473,10 @@
PCRE2_ERROR_NOMEMORY
- If a pattern contains back references, but the ovector is not big
- enough to remember the referenced substrings, PCRE2 gets a block of
+ If a pattern contains back references, but the ovector is not big
+ enough to remember the referenced substrings, PCRE2 gets a block of
memory at the start of matching to use for this purpose. There are some
- other special cases where extra memory is needed during matching. This
+ other special cases where extra memory is needed during matching. This
error is given when memory cannot be obtained.
PCRE2_ERROR_NULL
@@ -2478,12 +2485,12 @@
PCRE2_ERROR_RECURSELOOP
- This error is returned when pcre2_match() detects a recursion loop
- within the pattern. Specifically, it means that either the whole pat-
+ This error is returned when pcre2_match() detects a recursion loop
+ within the pattern. Specifically, it means that either the whole pat-
tern or a subpattern 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 com-
- plicated cases, in particular mutual recursions between two different
+ the same position in the subject string. Some simple patterns that
+ might do this are detected and faulted at compile time, but more com-
+ plicated cases, in particular mutual recursions between two different
subpatterns, cannot be detected until matching is attempted.
PCRE2_ERROR_RECURSIONLIMIT
@@ -2491,6 +2498,27 @@
The internal recursion limit was reached.
+OBTAINING A TEXTUAL ERROR MESSAGE
+
+ int pcre2_get_error_message(int errorcode, PCRE2_UCHAR *buffer,
+ PCRE2_SIZE bufflen);
+
+ A text message for an error code from any PCRE2 function (compile,
+ match, or auxiliary) can be obtained by calling pcre2_get_error_mes-
+ sage(). The code is passed as the first argument, with the remaining
+ two arguments specifying a code unit buffer and its length, into which
+ the text message is placed. Note that the message is returned in code
+ units of the appropriate width for the library that is being used.
+
+ The returned message is terminated with a trailing zero, and the func-
+ tion 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 mes-
+ sage 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.
+
+
EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
int pcre2_substring_length_bynumber(pcre2_match_data *match_data,
@@ -2861,7 +2889,8 @@
used in an assertion).
As for all PCRE2 errors, a text message that describes the error can be
- obtained by calling pcre2_get_error_message().
+ obtained by calling the pcre2_get_error_message() function (see
+ "Obtaining a textual error message" above).
DUPLICATE SUBPATTERN NAMES
@@ -2869,56 +2898,56 @@
int pcre2_substring_nametable_scan(const pcre2_code *code,
PCRE2_SPTR name, PCRE2_SPTR *first, PCRE2_SPTR *last);
- When a pattern is compiled with the PCRE2_DUPNAMES option, names for
- subpatterns are not required to be unique. Duplicate names are always
- allowed for subpatterns with the same number, created by using the (?|
- feature. Indeed, if such subpatterns are named, they are required to
+ When a pattern is compiled with the PCRE2_DUPNAMES option, names for
+ subpatterns are not required to be unique. Duplicate names are always
+ allowed for subpatterns with the same number, created by using the (?|
+ feature. Indeed, if such subpatterns are named, they are required to
use the same names.
Normally, patterns with duplicate names are such that in any one match,
- only one of the named subpatterns participates. An example is shown in
+ only one of the named subpatterns participates. An example is shown in
the pcre2pattern documentation.
- When duplicates are present, pcre2_substring_copy_byname() and
- pcre2_substring_get_byname() return the first substring corresponding
- to the given name that is set. Only if none are set is
- PCRE2_ERROR_UNSET is returned. The pcre2_substring_number_from_name()
+ When duplicates are present, pcre2_substring_copy_byname() and
+ pcre2_substring_get_byname() return the first substring corresponding
+ to the given name that is set. Only if none are set is
+ PCRE2_ERROR_UNSET is returned. The pcre2_substring_number_from_name()
function returns the error PCRE2_ERROR_NOUNIQUESUBSTRING when there are
duplicate names.
- If you want to get full details of all captured substrings for a given
- name, you must use the pcre2_substring_nametable_scan() function. The
- first argument is the compiled pattern, and the second is the name. If
- the third and fourth arguments are NULL, the function returns a group
+ If you want to get full details of all captured substrings for a given
+ name, you must use the pcre2_substring_nametable_scan() function. The
+ first argument is the compiled pattern, and the second is the name. If
+ the third and fourth arguments are NULL, the function returns a group
number for a unique name, or PCRE2_ERROR_NOUNIQUESUBSTRING otherwise.
When the third and fourth arguments are not NULL, they must be pointers
- to variables that are updated by the function. After it has run, they
+ to 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 function returns the length of each entry in code
- units. In both cases, PCRE2_ERROR_NOSUBSTRING is returned if there are
+ given name, and the function returns the length of each entry in code
+ units. In both cases, PCRE2_ERROR_NOSUBSTRING is returned if there are
no entries for the given name.
The format of the name table is described above in the section entitled
- Information about a pattern. Given all the relevant entries for the
- name, you can extract each of their numbers, and hence the captured
+ Information about a pattern. Given all the relevant entries for the
+ name, you can extract each of their numbers, and hence the captured
data.
FINDING ALL POSSIBLE MATCHES AT ONE POSITION
- The traditional matching function uses a similar algorithm to Perl,
- which stops when it finds the first match at a given point in the sub-
+ The traditional matching function uses a similar algorithm to Perl,
+ which stops when it finds the first match at a given point in the sub-
ject. 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 func-
+ match at a given position, consider using the alternative matching
+ function (see below) instead. If you cannot use the alternative func-
tion, you can kludge it up by making use of the callout facility, which
is described in the pcre2callout documentation.
What you have to do is to insert a callout right at the end of the pat-
- tern. When your callout function is called, extract and save the cur-
- rent matched substring. Then return 1, which forces pcre2_match() to
- backtrack and try other alternatives. Ultimately, when it runs out of
+ tern. When your callout function is called, extract and save the cur-
+ rent matched substring. Then return 1, which forces pcre2_match() to
+ backtrack and try other alternatives. Ultimately, when it runs out of
matches, pcre2_match() will yield PCRE2_ERROR_NOMATCH.
@@ -2930,26 +2959,26 @@
pcre2_match_context *mcontext,
int *workspace, PCRE2_SIZE wscount);
- The function pcre2_dfa_match() is called to match a subject string
- against a compiled pattern, using a matching algorithm that scans the
- subject string just once, 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. Never-
- theless, there are times when this kind of matching can be useful. For
- a discussion of the two matching algorithms, and a list of features
+ The function pcre2_dfa_match() is called to match a subject string
+ against a compiled pattern, using a matching algorithm that scans the
+ subject string just once, 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. Never-
+ theless, 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 pcre2_dfa_match() does not support, see the pcre2matching documen-
tation.
- The arguments for the pcre2_dfa_match() function are the same as for
+ The arguments for the pcre2_dfa_match() function are the same as for
pcre2_match(), plus two extras. The ovector within the match data block
is used in a different way, and this is described below. The other com-
- mon arguments are used in the same way as for pcre2_match(), so their
+ mon arguments are used in the same way as for pcre2_match(), so their
description is not repeated here.
- The two additional arguments provide workspace for the function. The
- workspace vector should contain at least 20 elements. It is used for
+ 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
+ workspace is needed for patterns and subjects where there are a lot of
potential matches.
Here is an example of a simple call to pcre2_dfa_match():
@@ -2969,45 +2998,45 @@
Option bits for pcre_dfa_match()
- The unused bits of the options argument for pcre2_dfa_match() must be
- zero. The only bits that may be set are PCRE2_ANCHORED, PCRE2_NOTBOL,
+ The unused bits of the options argument for pcre2_dfa_match() must be
+ zero. The only bits that may be set are PCRE2_ANCHORED, 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 pcre2_match(), so their description
+ PCRE2_DFA_SHORTEST, and PCRE2_DFA_RESTART. All but the last four of
+ these are exactly the same as for pcre2_match(), so their description
is not repeated here.
PCRE2_PARTIAL_HARD
PCRE2_PARTIAL_SOFT
- These have the same general effect as they do for pcre2_match(), but
- the details are slightly different. When PCRE2_PARTIAL_HARD is set for
- pcre2_dfa_match(), it returns PCRE2_ERROR_PARTIAL if the end of the
+ These have the same general effect as they do for pcre2_match(), but
+ the details are slightly different. When PCRE2_PARTIAL_HARD is set for
+ pcre2_dfa_match(), 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 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 por-
- tion of the string that was inspected when the longest partial match
+ tion 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
+ more detailed discussion of partial and multi-segment matching, with
examples, in the pcre2partial documentation.
PCRE2_DFA_SHORTEST
- Setting the PCRE2_DFA_SHORTEST option causes the matching algorithm to
+ 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 alterna-
- tive algorithm works, this is necessarily the shortest possible match
+ tive algorithm works, this is necessarily the shortest possible match
at the first possible matching point in the subject string.
PCRE2_DFA_RESTART
- When pcre2_dfa_match() returns a partial match, it is possible to call
+ When pcre2_dfa_match() 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 workspace and wscount options must reference the same
- vector as before because data about the match so far is left in them
+ it is set, the workspace and wscount 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
pcre2partial documentation.
@@ -3015,8 +3044,8 @@
When pcre2_dfa_match() succeeds, it may have matched more than one sub-
string 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,
+ 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
<.*>
@@ -3031,17 +3060,17 @@
<something> <something else>
<something>
- On success, the yield of the function is a number greater than zero,
- which is the number of matched substrings. The offsets of the sub-
- strings are returned in the ovector, and can be extracted by number in
- the same way as for pcre2_match(), but the numbers bear no relation to
- any capturing groups that may exist in the pattern, because DFA match-
+ On success, the yield of the function is a number greater than zero,
+ which is the number of matched substrings. The offsets of the sub-
+ strings are returned in the ovector, and can be extracted by number in
+ the same way as for pcre2_match(), but the numbers bear no relation to
+ any capturing groups that may exist in the pattern, because DFA match-
ing does not support group capture.
- Calls to the convenience functions that extract substrings by name
- return the error PCRE2_ERROR_DFA_UFUNC (unsupported function) if used
+ 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 return PCRE2_ERROR_NOSUBSTRING, and the meanings of some
+ number never return PCRE2_ERROR_NOSUBSTRING, and the meanings of some
other errors are slightly different:
PCRE2_ERROR_UNAVAILABLE
@@ -3051,64 +3080,64 @@
PCRE2_ERROR_UNSET
- There is a slot in the ovector for this substring, but there were
+ There is a slot in the ovector for this substring, but there were
insufficient matches to fill it.
- 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
+ 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.
- NOTE: PCRE2's "auto-possessification" optimization usually applies to
- character repeats at the end of a pattern (as well as internally). For
- example, the pattern "a\d+" is compiled as if it were "a\d++". For DFA
- matching, this means that only one possible match is found. If you
- really do want multiple matches in such cases, either use an ungreedy
- repeat auch as "a\d+?" or set the PCRE2_NO_AUTO_POSSESS option when
+ NOTE: PCRE2's "auto-possessification" optimization usually applies to
+ character repeats at the end of a pattern (as well as internally). For
+ example, the pattern "a\d+" is compiled as if it were "a\d++". For DFA
+ matching, this means that only one possible match is found. If you
+ really do want multiple matches in such cases, either use an ungreedy
+ repeat auch as "a\d+?" or set the PCRE2_NO_AUTO_POSSESS option when
compiling.
Error returns from pcre2_dfa_match()
The pcre2_dfa_match() function returns a negative number when it fails.
- Many of the errors are the same as for pcre2_match(), as described
+ Many of the errors are the same as for pcre2_match(), as described
above. There are in addition the following errors that are specific to
pcre2_dfa_match():
PCRE2_ERROR_DFA_UITEM
- This return is given if pcre2_dfa_match() encounters an item in the
- pattern that it does not support, for instance, the use of \C in a UTF
+ This return is given if pcre2_dfa_match() encounters an item in the
+ pattern that it does not support, for instance, the use of \C in a UTF
mode or a back reference.
PCRE2_ERROR_DFA_UCOND
- This return is given if pcre2_dfa_match() encounters a condition item
- that uses a back reference for the condition, or a test for recursion
+ This return is given if pcre2_dfa_match() encounters a condition item
+ that uses a back reference for the condition, or a test for recursion
in a specific group. These are not supported.
PCRE2_ERROR_DFA_WSSIZE
- This return is given if pcre2_dfa_match() runs out of space in the
+ This return is given if pcre2_dfa_match() runs out of space in the
workspace vector.
PCRE2_ERROR_DFA_RECURSE
- When a recursive subpattern is processed, the matching function calls
+ When a recursive subpattern is processed, the matching function calls
itself recursively, using private memory for the ovector and workspace.
- This error is given if the internal ovector is not large enough. This
+ This error is given if the internal ovector is not large enough. This
should be extremely rare, as a vector of size 1000 is used.
PCRE2_ERROR_DFA_BADRESTART
- When pcre2_dfa_match() is called with the PCRE2_DFA_RESTART option,
- some plausibility checks are made on the contents of the workspace,
- which should contain data about the previous partial match. If any of
+ When pcre2_dfa_match() is called with the PCRE2_DFA_RESTART option,
+ 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.
SEE ALSO
- pcre2build(3), pcre2callout(3), pcre2demo(3), pcre2matching(3),
+ pcre2build(3), pcre2callout(3), pcre2demo(3), pcre2matching(3),
pcre2partial(3), pcre2posix(3), pcre2sample(3), pcre2stack(3),
pcre2unicode(3).
@@ -3122,7 +3151,7 @@
REVISION
- Last updated: 05 June 2016
+ Last updated: 17 June 2016
Copyright (c) 1997-2016 University of Cambridge.
------------------------------------------------------------------------------
Modified: code/trunk/doc/pcre2_get_error_message.3
===================================================================
--- code/trunk/doc/pcre2_get_error_message.3 2016-06-14 16:14:52 UTC (rev 525)
+++ code/trunk/doc/pcre2_get_error_message.3 2016-06-17 11:30:27 UTC (rev 526)
@@ -1,4 +1,4 @@
-.TH PCRE2_GET_ERROR_MESSAGE 3 "21 October 2014" "PCRE2 10.00"
+.TH PCRE2_GET_ERROR_MESSAGE 3 "17 June 2016" "PCRE2 10.22"
.SH NAME
PCRE2 - Perl-compatible regular expressions (revised API)
.SH SYNOPSIS
@@ -23,7 +23,10 @@
\fIbufflen\fP the length of the buffer (code units)
.sp
The function returns the length of the message, excluding the trailing zero, or
-a negative error code if the buffer is too small.
+the negative error code PCRE2_ERROR_NOMEMORY if the buffer is too small. In
+this case, the returned message is truncated (but still with a trailing zero).
+If \fIerrorcode\fP does not contain a recognized error code number, the
+negative value PCRE2_ERROR_BADDATA is returned.
.P
There is a complete description of the PCRE2 native API in the
.\" HREF
Modified: code/trunk/doc/pcre2api.3
===================================================================
--- code/trunk/doc/pcre2api.3 2016-06-14 16:14:52 UTC (rev 525)
+++ code/trunk/doc/pcre2api.3 2016-06-17 11:30:27 UTC (rev 526)
@@ -1,4 +1,4 @@
-.TH PCRE2API 3 "05 June 2016" "PCRE2 10.22"
+.TH PCRE2API 3 "17 June 2016" "PCRE2 10.22"
.SH NAME
PCRE2 - Perl-compatible regular expressions (revised API)
.sp
@@ -1032,7 +1032,7 @@
The pattern is defined by a pointer to a string of code units and a length. If
the pattern is zero-terminated, the length can be specified as
PCRE2_ZERO_TERMINATED. The function returns a pointer to a block of memory that
-contains the compiled pattern and related data.
+contains the compiled pattern and related data, or NULL if an error occurred.
.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
@@ -1054,8 +1054,9 @@
.P
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
-be referenced by the extraction functions. After running a match, you must not
-free a compiled pattern (or a subject string) until after all operations on the
+be referenced by the substring extraction functions. After running a match, you
+must not free a compiled pattern (or a subject string) until after all
+operations on the
.\" HTML <a href="#matchdatablock">
.\" </a>
match data block
@@ -1086,14 +1087,23 @@
.\"
.P
If \fIerrorcode\fP or \fIerroroffset\fP is NULL, \fBpcre2_compile()\fP returns
-NULL immediately. Otherwise, if compilation of a pattern fails,
-\fBpcre2_compile()\fP returns NULL, having set these variables to an error code
-and an offset (number of code units) within the pattern, respectively. The
-\fBpcre2_get_error_message()\fP function provides a textual message for each
-error code. Compilation errors are positive numbers, but UTF formatting errors
-are negative numbers. For an invalid UTF-8 or UTF-16 string, the offset is that
-of the first code unit of the failing character.
+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
+and \fBpcre2_compile()\fP returns a non-NULL value.
.P
+The \fBpcre2_get_error_message()\fP function (see "Obtaining a textual error
+message"
+.\" HTML <a href="#geterrormessage">
+.\" </a>
+below)
+.\"
+provides a textual message for each error code. Compilation errors have
+positive error codes; UTF formatting error codes are negative. For an invalid
+UTF-8 or UTF-16 string, the offset is that of the first code unit of the
+failing character.
+.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
@@ -1479,15 +1489,21 @@
.SH "COMPILATION ERROR CODES"
.rs
.sp
-There are over 80 positive error codes that \fBpcre2_compile()\fP may return if
-it finds an error in the pattern. There are also some negative error codes that
-are used for invalid UTF strings. These are the same as given by
-\fBpcre2_match()\fP and \fBpcre2_dfa_match()\fP, and are described in the
+There are over 80 positive error codes that \fBpcre2_compile()\fP may return
+(via \fIerrorcode\fP) if it finds an error in the pattern. There are also some
+negative error codes that are used for invalid UTF strings. These are the same
+as given by \fBpcre2_match()\fP and \fBpcre2_dfa_match()\fP, and are described
+in the
.\" HREF
\fBpcre2unicode\fP
.\"
-page. The \fBpcre2_get_error_message()\fP function can be called to obtain a
-textual error message from any error code.
+page. The \fBpcre2_get_error_message()\fP function (see "Obtaining a textual
+error message"
+.\" HTML <a href="#geterrormessage">
+.\" </a>
+below)
+.\"
+can be called to obtain a textual error message from any error code.
.
.
.\" HTML <a name="jitcompiling"></a>
@@ -2454,11 +2470,16 @@
.rs
.sp
If \fBpcre2_match()\fP fails, it returns a negative number. This can be
-converted to a text string by calling \fBpcre2_get_error_message()\fP. 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
+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
.\" HREF
\fBpcre2unicode\fP
.\"
@@ -2571,6 +2592,30 @@
The internal recursion limit was reached.
.
.
+.\" 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
+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
+code unit buffer and its length, into which the text message is placed. Note
+that the message is returned in code units of the appropriate width for the
+library that is being used.
+.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.
+.
+.
.\" HTML <a name="extractbynumber"></a>
.SH "EXTRACTING CAPTURED SUBSTRINGS BY NUMBER"
.rs
@@ -2948,7 +2993,12 @@
started, which can happen if \eK is used in an assertion).
.P
As for all PCRE2 errors, a text message that describes the error can be
-obtained by calling \fBpcre2_get_error_message()\fP.
+obtained by calling the \fBpcre2_get_error_message()\fP function (see
+"Obtaining a textual error message"
+.\" HTML <a href="#geterrormessage">
+.\" </a>
+above).
+.\"
.
.
.SH "DUPLICATE SUBPATTERN NAMES"
@@ -3242,6 +3292,6 @@
.rs
.sp
.nf
-Last updated: 05 June 2016
+Last updated: 17 June 2016
Copyright (c) 1997-2016 University of Cambridge.
.fi
Modified: code/trunk/doc/pcre2test.1
===================================================================
--- code/trunk/doc/pcre2test.1 2016-06-14 16:14:52 UTC (rev 525)
+++ code/trunk/doc/pcre2test.1 2016-06-17 11:30:27 UTC (rev 526)
@@ -1,4 +1,4 @@
-.TH PCRE2TEST 1 "05 June 2016" "PCRE 10.22"
+.TH PCRE2TEST 1 "17 June 2016" "PCRE 10.22"
.SH NAME
pcre2test - a program for testing Perl-compatible regular expressions.
.SH SYNOPSIS
@@ -68,7 +68,7 @@
further data is read.
.P
For maximum portability, therefore, it is safest to avoid non-printing
-characters in \fBpcre2test\fP input files. There is a facility for specifying
+characters in \fBpcre2test\fP input files. There is a facility for specifying
some or all of a pattern's characters as hexadecimal pairs, thus making it
possible to include binary zeroes in a pattern for testing purposes. Subject
lines are processed for backslash escapes, which makes it possible to include
@@ -143,6 +143,12 @@
using the \fBpcre2_dfa_match()\fP function instead of the default
\fBpcre2_match()\fP.
.TP 10
+\fB-error\fP \fInumber[,number,...]\fP
+Call \fBpcre2_get_error_message()\fP for each of the error numbers in the
+comma-separated list, display the resulting messages on the standard output,
+then exit with zero exit code. The numbers may be positive or negative. This is
+a convenience facility for PCRE2 maintainers.
+.TP 10
\fB-help\fP
Output a brief summary these options and then exit.
.TP 10
@@ -536,7 +542,7 @@
null_context compile with a NULL context
parens_nest_limit=<n> set maximum parentheses depth
posix use the POSIX API
- posix_nosub use the POSIX API with REG_NOSUB
+ posix_nosub use the POSIX API with REG_NOSUB
push push compiled pattern onto the stack
pushcopy push a copy onto the stack
stackguard=<number> test the stackguard feature
@@ -621,22 +627,22 @@
.SS "Specifying pattern characters in hexadecimal"
.rs
.sp
-The \fBhex\fP modifier specifies that the characters of the pattern, except for
+The \fBhex\fP modifier specifies that the characters of the pattern, except for
substrings enclosed in single or double quotes, are to be interpreted as pairs
of hexadecimal digits. This feature is provided as a way of creating patterns
that contain binary zeros and other non-printing characters. White space is
-permitted between pairs of digits. For example, this pattern contains three
+permitted between pairs of digits. For example, this pattern contains three
characters:
.sp
/ab 32 59/hex
.sp
-Parts of such a pattern are taken literally if quoted. This pattern contains
+Parts of such a pattern are taken literally if quoted. This pattern contains
nine characters, only two of which are specified in hexadecimal:
.sp
/ab "literal" 32/hex
-.sp
+.sp
Either single or double quotes may be used. There is no way of including
-the delimiter within a substring.
+the delimiter within a substring.
.P
By default, \fBpcre2test\fP passes patterns as zero-terminated strings to
\fBpcre2_compile()\fP, giving the length as PCRE2_ZERO_TERMINATED. However, for
@@ -897,9 +903,9 @@
section entitled "Saving and restoring compiled patterns"
.\" HTML <a href="#saverestore">
.\" </a>
-below. If \fBpushcopy\fP is used instead of \fBpush\fP, a copy of the compiled
-pattern is stacked, leaving the original as current, ready to match the
-following input lines. This provides a way of testing the
+below. If \fBpushcopy\fP is used instead of \fBpush\fP, a copy of the compiled
+pattern is stacked, leaving the original as current, ready to match the
+following input lines. This provides a way of testing the
\fBpcre2_code_copy()\fP function.
.\"
The \fBpush\fP and \fBpushcopy \fP modifiers are incompatible with compilation
@@ -931,7 +937,7 @@
anchored set PCRE2_ANCHORED
dfa_restart set PCRE2_DFA_RESTART
dfa_shortest set PCRE2_DFA_SHORTEST
- no_jit set PCRE2_NO_JIT
+ no_jit set PCRE2_NO_JIT
no_utf_check set PCRE2_NO_UTF_CHECK
notbol set PCRE2_NOTBOL
notempty set PCRE2_NOTEMPTY
@@ -991,7 +997,7 @@
substitute_unset_empty use PCRE2_SUBSTITUTE_UNSET_EMPTY
zero_terminate pass the subject as zero-terminated
.sp
-The effects of these modifiers are described in the following sections. When
+The effects of these modifiers are described in the following sections. When
matching via the POSIX wrapper API, the \fBaftertext\fP, \fBallaftertext\fP,
and \fBovector\fP subject modifiers work as described below. All other
modifiers are either ignored, with a warning message, or cause an error.
@@ -1499,8 +1505,8 @@
This output indicates that callout number 0 occurred for a match attempt
starting at the fourth character of the subject string, when the pointer was at
the seventh character, and when the next pattern item was \ed. Just
-one circumflex is output if the start and current positions are the same, or if
-the current position precedes the start position, which can happen if the
+one circumflex is output if the start and current positions are the same, or if
+the current position precedes the start position, which can happen if the
callout is in a lookbehind assertion.
.P
Callouts numbered 255 are assumed to be automatic callouts, inserted as a
@@ -1602,7 +1608,7 @@
stacked, leaving the original available for immediate matching. By using
\fBpush\fP and/or \fBpushcopy\fP, a number of patterns can be compiled and
retained. These modifiers are incompatible with \fBposix\fP, and control
-modifiers that act at match time are ignored (with a message) for the stacked
+modifiers that act at match time are ignored (with a message) for the stacked
patterns. The \fBjitverify\fP modifier applies only at compile time.
.P
The command
@@ -1647,8 +1653,8 @@
If \fBjitverify\fP is used with #pop, it does not automatically imply
\fBjit\fP, which is different behaviour from when it is used on a pattern.
.P
-The #popcopy command is analagous to the \fBpushcopy\fP modifier in that it
-makes current a copy of the topmost stack pattern, leaving the original still
+The #popcopy command is analagous to the \fBpushcopy\fP modifier in that it
+makes current a copy of the topmost stack pattern, leaving the original still
on the stack.
.
.
@@ -1675,6 +1681,6 @@
.rs
.sp
.nf
-Last updated: 05 June 2016
+Last updated: 17 June 2016
Copyright (c) 1997-2016 University of Cambridge.
.fi
Modified: code/trunk/doc/pcre2test.txt
===================================================================
--- code/trunk/doc/pcre2test.txt 2016-06-14 16:14:52 UTC (rev 525)
+++ code/trunk/doc/pcre2test.txt 2016-06-17 11:30:27 UTC (rev 526)
@@ -138,6 +138,13 @@
is done using the pcre2_dfa_match() function instead of the
default pcre2_match().
+ -error number[,number,...]
+ Call pcre2_get_error_message() for each of the error numbers
+ in the comma-separated list, display the resulting messages
+ on the standard output, then exit with zero exit code. The
+ numbers may be positive or negative. This is a convenience
+ facility for PCRE2 maintainers.
+
-help Output a brief summary these options and then exit.
-i Behave as if each pattern has the /info modifier; information
@@ -1539,5 +1546,5 @@
REVISION
- Last updated: 05 June 2016
+ Last updated: 17 June 2016
Copyright (c) 1997-2016 University of Cambridge.
Modified: code/trunk/src/pcre2_error.c
===================================================================
--- code/trunk/src/pcre2_error.c 2016-06-14 16:14:52 UTC (rev 525)
+++ code/trunk/src/pcre2_error.c 2016-06-17 11:30:27 UTC (rev 526)
@@ -252,7 +252,7 @@
/* 60 */
"match with end before start is not supported\0"
"too many replacements (more than INT_MAX)\0"
- "bad serialized data\0"
+ "bad serialized data\0"
;
@@ -277,7 +277,6 @@
PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_get_error_message(int enumber, PCRE2_UCHAR *buffer, size_t size)
{
-char xbuff[128];
const unsigned char *message;
size_t i;
int n;
@@ -284,25 +283,26 @@
if (size == 0) return PCRE2_ERROR_NOMEMORY;
-if (enumber > COMPILE_ERROR_BASE) /* Compile error */
+if (enumber >= COMPILE_ERROR_BASE) /* Compile error */
{
message = compile_error_texts;
n = enumber - COMPILE_ERROR_BASE;
}
-else /* Match or UTF error */
+else if (enumber < 0) /* Match or UTF error */
{
message = match_error_texts;
n = -enumber;
}
+else /* Invalid error number */
+ {
+ message = (unsigned char *)"\0"; /* Empty message list */
+ n = 1;
+ }
for (; n > 0; n--)
{
while (*message++ != CHAR_NULL) {};
- if (*message == CHAR_NULL)
- {
- sprintf(xbuff, "No text for error %d", enumber);
- break;
- }
+ if (*message == CHAR_NULL) return PCRE2_ERROR_BADDATA;
}
for (i = 0; *message != 0; i++)
Modified: code/trunk/src/pcre2test.c
===================================================================
--- code/trunk/src/pcre2test.c 2016-06-14 16:14:52 UTC (rev 525)
+++ code/trunk/src/pcre2test.c 2016-06-17 11:30:27 UTC (rev 526)
@@ -3018,9 +3018,9 @@
dlen = strlen((char *)here);
here += dlen;
- /* Check for end of line reached. Take care not to read data from before
+ /* Check for end of line reached. Take care not to read data from before
start (dlen will be zero for a file starting with a binary zero). */
-
+
if (here > start && here[-1] == '\n') return start;
/* If we have not read a newline when reading a file, we have either filled
@@ -4774,7 +4774,7 @@
if (rc != 0)
{
size_t bsize, usize;
- int psize;
+ int psize;
preg.re_pcre2_code = NULL; /* In case something was left in there */
preg.re_match_data = NULL;
@@ -4784,9 +4784,9 @@
if (bsize + 8 < pbuffer8_size)
memcpy(pbuffer8 + bsize, "DEADBEEF", 8);
usize = regerror(rc, &preg, (char *)pbuffer8, bsize);
-
- /* Inside regerror(), snprintf() is used. If the buffer is too small, some
- versions of snprintf() put a zero byte at the end, but others do not.
+
+ /* Inside regerror(), snprintf() is used. If the buffer is too small, some
+ versions of snprintf() put a zero byte at the end, but others do not.
Therefore, we print a maximum of one less than the size of the buffer. */
psize = (int)bsize - 1;
@@ -6885,6 +6885,7 @@
printf(" unicode Unicode and UTF support enabled [0, 1]\n");
printf(" -d set default pattern control 'debug'\n");
printf(" -dfa set default subject control 'dfa'\n");
+printf(" -error <n,m,..> show messages for error numbers, then exit\n");
printf(" -help show usage information\n");
printf(" -i set default pattern control 'info'\n");
printf(" -jit set default pattern control 'jit'\n");
@@ -7062,6 +7063,7 @@
BOOL skipping = FALSE;
char *arg_subject = NULL;
char *arg_pattern = NULL;
+char *arg_error = NULL;
/* The offsets to the options and control bits fields of the pattern and data
control blocks must be the same so that common options and controls such as
@@ -7273,6 +7275,12 @@
/* The following options save their data for processing once we know what
the running mode is. */
+ else if (strcmp(arg, "-error") == 0)
+ {
+ arg_error = argv[op+1];
+ goto CHECK_VALUE_EXISTS;
+ }
+
else if (strcmp(arg, "-subject") == 0)
{
arg_subject = argv[op+1];
@@ -7306,6 +7314,88 @@
argc--;
}
+/* If -error was present, get the error numbers, show the messages, and exit.
+We wait to do this until we know which mode we are in. */
+
+if (arg_error != NULL)
+ {
+ int len;
+ int errcode;
+ char *endptr;
+
+/* Ensure the relevant non-8-bit buffer is available. */
+
+#ifdef SUPPORT_PCRE2_16
+ if (test_mode == PCRE16_MODE)
+ {
+ pbuffer16_size = 256;
+ pbuffer16 = (uint16_t *)malloc(pbuffer16_size);
+ if (pbuffer16 == NULL)
+ {
+ fprintf(stderr, "pcre2test: malloc(%lu) failed for pbuffer16\n",
+ (unsigned long int)pbuffer16_size);
+ yield = 1;
+ goto EXIT;
+ }
+ }
+#endif
+
+#ifdef SUPPORT_PCRE2_32
+ if (test_mode == PCRE32_MODE)
+ {
+ pbuffer32_size = 256;
+ pbuffer32 = (uint32_t *)malloc(pbuffer32_size);
+ if (pbuffer32 == NULL)
+ {
+ fprintf(stderr, "pcre2test: malloc(%lu) failed for pbuffer32\n",
+ (unsigned long int)pbuffer32_size);
+ yield = 1;
+ goto EXIT;
+ }
+ }
+#endif
+
+ /* Loop along a list of error numbers. */
+
+ for (;;)
+ {
+ errcode = strtol(arg_error, &endptr, 10);
+ if (*endptr != 0 && *endptr != CHAR_COMMA)
+ {
+ fprintf(stderr, "** '%s' is not a valid error number list\n", arg_error);
+ yield = 1;
+ goto EXIT;
+ }
+ printf("Error %d: ", errcode);
+ PCRE2_GET_ERROR_MESSAGE(len, errcode, pbuffer);
+ if (len < 0)
+ {
+ switch (len)
+ {
+ case PCRE2_ERROR_BADDATA:
+ printf("PCRE2_ERROR_BADDATA (unknown error number)");
+ break;
+
+ case PCRE2_ERROR_NOMEMORY:
+ printf("PCRE2_ERROR_NOMEMORY (buffer too small)");
+ break;
+
+ default:
+ printf("Unexpected return (%d) from pcre2_get_error_message()", len);
+ break;
+ }
+ }
+ else
+ {
+ PCHARSV(CASTVAR(void *, pbuffer), 0, len, FALSE, stdout);
+ }
+ printf("\n");
+ if (*endptr == 0) goto EXIT;
+ arg_error = endptr + 1;
+ }
+ /* Control never reaches here */
+ } /* End of -error handling */
+
/* Initialize things that cannot be done until we know which test mode we are
running in. When HEAP_MATCH_RECURSE is undefined, calling pcre2_set_recursion_
memory_management() is a no-op, but we call it in order to exercise it. Also
Modified: code/trunk/testdata/testoutput2
===================================================================
--- code/trunk/testdata/testoutput2 2016-06-14 16:14:52 UTC (rev 525)
+++ code/trunk/testdata/testoutput2 2016-06-17 11:30:27 UTC (rev 526)
@@ -15187,3 +15187,11 @@
No match
# End of testinput2
+Error -63: PCRE2_ERROR_BADDATA (unknown error number)
+Error -62: bad serialized data
+Error -2: partial match
+Error -1: no match
+Error 0: PCRE2_ERROR_BADDATA (unknown error number)
+Error 100: no error
+Error 188: pattern string is longer than the limit set by the application
+Error 189: PCRE2_ERROR_BADDATA (unknown error number)
