Revision: 950
http://www.exim.org/viewvc/pcre2?view=rev&revision=950
Author: ph10
Date: 2018-06-27 18:20:58 +0100 (Wed, 27 Jun 2018)
Log Message:
-----------
Documentation update to clarify what PCRE2 serialization is.
Modified Paths:
--------------
code/trunk/doc/html/pcre2_serialize_decode.html
code/trunk/doc/html/pcre2_serialize_encode.html
code/trunk/doc/html/pcre2_serialize_free.html
code/trunk/doc/html/pcre2_serialize_get_number_of_codes.html
code/trunk/doc/html/pcre2api.html
code/trunk/doc/html/pcre2serialize.html
code/trunk/doc/html/pcre2test.html
code/trunk/doc/pcre2.txt
code/trunk/doc/pcre2_serialize_decode.3
code/trunk/doc/pcre2_serialize_encode.3
code/trunk/doc/pcre2_serialize_free.3
code/trunk/doc/pcre2_serialize_get_number_of_codes.3
code/trunk/doc/pcre2api.3
code/trunk/doc/pcre2serialize.3
code/trunk/doc/pcre2test.1
code/trunk/doc/pcre2test.txt
Modified: code/trunk/doc/html/pcre2_serialize_decode.html
===================================================================
--- code/trunk/doc/html/pcre2_serialize_decode.html 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/html/pcre2_serialize_decode.html 2018-06-27 17:20:58 UTC (rev 950)
@@ -28,7 +28,10 @@
</b><br>
<P>
This function decodes a serialized set of compiled patterns back into a list of
-individual patterns. Its arguments are:
+individual patterns. This is possible only on a host that is running the same
+version of PCRE2, with the same code unit width, and the host must also have
+the same endianness, pointer width and PCRE2_SIZE type. The arguments for
+<b>pcre2_serialize_decode()</b> are:
<pre>
<i>codes</i> pointer to a vector in which to build the list
<i>number_of_codes</i> number of slots in the vector
@@ -54,8 +57,8 @@
<P>
There is a complete description of the PCRE2 native API in the
<a href="pcre2api.html"><b>pcre2api</b></a>
-page and a description of the POSIX API in the
-<a href="pcre2posix.html"><b>pcre2posix</b></a>
+page and a description of the serialization functions in the
+<a href="pcre2serialize.html"><b>pcre2serialize</b></a>
page.
<p>
Return to the <a href="index.html">PCRE2 index page</a>.
Modified: code/trunk/doc/html/pcre2_serialize_encode.html
===================================================================
--- code/trunk/doc/html/pcre2_serialize_encode.html 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/html/pcre2_serialize_encode.html 2018-06-27 17:20:58 UTC (rev 950)
@@ -28,7 +28,12 @@
</b><br>
<P>
This function encodes a list of compiled patterns into a byte stream that can
-be saved on disc or elsewhere. Its arguments are:
+be saved on disc or elsewhere. Note that this is not an abstract format like
+Java or .NET. Conversion of the byte stream back into usable compiled patterns
+can only happen on a host that is running the same version of PCRE2, with the
+same code unit width, and the host must also have the same endianness, pointer
+width and PCRE2_SIZE type. The arguments for <b>pcre2_serialize_encode()</b>
+are:
<pre>
<i>codes</i> pointer to a vector containing the list
<i>number_of_codes</i> number of slots in the vector
@@ -53,8 +58,8 @@
<P>
There is a complete description of the PCRE2 native API in the
<a href="pcre2api.html"><b>pcre2api</b></a>
-page and a description of the POSIX API in the
-<a href="pcre2posix.html"><b>pcre2posix</b></a>
+page and a description of the serialization functions in the
+<a href="pcre2serialize.html"><b>pcre2serialize</b></a>
page.
<p>
Return to the <a href="index.html">PCRE2 index page</a>.
Modified: code/trunk/doc/html/pcre2_serialize_free.html
===================================================================
--- code/trunk/doc/html/pcre2_serialize_free.html 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/html/pcre2_serialize_free.html 2018-06-27 17:20:58 UTC (rev 950)
@@ -32,8 +32,8 @@
<P>
There is a complete description of the PCRE2 native API in the
<a href="pcre2api.html"><b>pcre2api</b></a>
-page and a description of the POSIX API in the
-<a href="pcre2posix.html"><b>pcre2posix</b></a>
+page and a description of the serialization functions in the
+<a href="pcre2serialize.html"><b>pcre2serialize</b></a>
page.
<p>
Return to the <a href="index.html">PCRE2 index page</a>.
Modified: code/trunk/doc/html/pcre2_serialize_get_number_of_codes.html
===================================================================
--- code/trunk/doc/html/pcre2_serialize_get_number_of_codes.html 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/html/pcre2_serialize_get_number_of_codes.html 2018-06-27 17:20:58 UTC (rev 950)
@@ -41,8 +41,8 @@
<P>
There is a complete description of the PCRE2 native API in the
<a href="pcre2api.html"><b>pcre2api</b></a>
-page and a description of the POSIX API in the
-<a href="pcre2posix.html"><b>pcre2posix</b></a>
+page and a description of the serialization functions in the
+<a href="pcre2serialize.html"><b>pcre2serialize</b></a>
page.
<p>
Return to the <a href="index.html">PCRE2 index page</a>.
Modified: code/trunk/doc/html/pcre2api.html
===================================================================
--- code/trunk/doc/html/pcre2api.html 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/html/pcre2api.html 2018-06-27 17:20:58 UTC (rev 950)
@@ -2283,11 +2283,16 @@
<br><a name="SEC25" href="#TOC1">SERIALIZATION AND PRECOMPILING</a><br>
<P>
It is possible to save compiled patterns on disc or elsewhere, and reload them
-later, subject to a number of restrictions. The functions whose names begin
-with <b>pcre2_serialize_</b> are used for this purpose. They are described in
-the
+later, subject to a number of restrictions. The host on which the patterns are
+reloaded must be running the same version of PCRE2, with the same code unit
+width, and must also have the same endianness, pointer width, and PCRE2_SIZE
+type. Before compiled patterns can be saved, they must be converted to a
+"serialized" form, which in the case of PCRE2 is really just a bytecode dump.
+The functions whose names begin with <b>pcre2_serialize_</b> are used for
+converting to and from the serialized form. They are described in the
<a href="pcre2serialize.html"><b>pcre2serialize</b></a>
-documentation.
+documentation. Note that PCRE2 serialization does not convert compiled patterns
+to an abstract format like Java or .NET serialization.
<a name="matchdatablock"></a></P>
<br><a name="SEC26" href="#TOC1">THE MATCH DATA BLOCK</a><br>
<P>
Modified: code/trunk/doc/html/pcre2serialize.html
===================================================================
--- code/trunk/doc/html/pcre2serialize.html 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/html/pcre2serialize.html 2018-06-27 17:20:58 UTC (rev 950)
@@ -49,6 +49,15 @@
PCRE2's 16-bit library cannot be reloaded on a 64-bit system, nor can they be
reloaded using the 8-bit library.
</P>
+<P>
+Note that "serialization" in PCRE2 does not convert compiled patterns to an
+abstract format like Java or .NET serialization. The serialized output is
+really just a bytecode dump, which is why it can only be reloaded in the same
+environment as the one that created it. Hence the restrictions mentioned above.
+Applications that are not statically linked with a fixed version of PCRE2 must
+be prepared to recompile patterns from their sources, in order to be immune to
+PCRE2 upgrades.
+</P>
<br><a name="SEC2" href="#TOC1">SECURITY CONCERNS</a><br>
<P>
The facility for saving and restoring compiled patterns is intended for use
@@ -62,11 +71,11 @@
</P>
<br><a name="SEC3" href="#TOC1">SAVING COMPILED PATTERNS</a><br>
<P>
-Before compiled patterns can be saved they must be serialized, that is,
-converted to a stream of bytes. A single byte stream may contain any number of
-compiled patterns, but they must all use the same character tables. A single
-copy of the tables is included in the byte stream (its size is 1088 bytes). For
-more details of character tables, see the
+Before compiled patterns can be saved they must be serialized, which in PCRE2
+means converting the pattern to a stream of bytes. A single byte stream may
+contain any number of compiled patterns, but they must all use the same
+character tables. A single copy of the tables is included in the byte stream
+(its size is 1088 bytes). For more details of character tables, see the
<a href="pcre2api.html#localesupport">section on locale support</a>
in the
<a href="pcre2api.html"><b>pcre2api</b></a>
@@ -193,9 +202,9 @@
</P>
<br><a name="SEC6" href="#TOC1">REVISION</a><br>
<P>
-Last updated: 21 March 2017
+Last updated: 27 June 2018
<br>
-Copyright © 1997-2017 University of Cambridge.
+Copyright © 1997-2018 University of Cambridge.
<br>
<p>
Return to the <a href="index.html">PCRE2 index page</a>.
Modified: code/trunk/doc/html/pcre2test.html
===================================================================
--- code/trunk/doc/html/pcre2test.html 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/html/pcre2test.html 2018-06-27 17:20:58 UTC (rev 950)
@@ -1927,17 +1927,23 @@
can be used to test these functions.
</P>
<P>
-When a pattern with <b>push</b> modifier is successfully compiled, it is pushed
-onto a stack of compiled patterns, and <b>pcre2test</b> expects the next line to
-contain a new pattern (or command) instead of a subject line. By contrast,
-the <b>pushcopy</b> modifier causes a copy of the compiled pattern to be
-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
-patterns. The <b>jitverify</b> modifier applies only at compile time.
+Note that "serialization" in PCRE2 does not convert compiled patterns to an
+abstract format like Java or .NET. It just makes a reloadable byte code stream.
+Hence the restrictions on reloading mentioned above.
</P>
<P>
+In <b>pcre2test</b>, when a pattern with <b>push</b> modifier is successfully
+compiled, it is pushed onto a stack of compiled patterns, and <b>pcre2test</b>
+expects the next line to contain a new pattern (or command) instead of a
+subject line. By contrast, the <b>pushcopy</b> modifier causes a copy of the
+compiled pattern to be 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 patterns. The <b>jitverify</b> modifier applies only at compile
+time.
+</P>
+<P>
The command
<pre>
#save <filename>
@@ -1996,7 +2002,7 @@
</P>
<br><a name="SEC21" href="#TOC1">REVISION</a><br>
<P>
-Last updated: 25 April 2018
+Last updated: 27 June 2018
<br>
Copyright © 1997-2018 University of Cambridge.
<br>
Modified: code/trunk/doc/pcre2.txt
===================================================================
--- code/trunk/doc/pcre2.txt 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/pcre2.txt 2018-06-27 17:20:58 UTC (rev 950)
@@ -2260,9 +2260,16 @@
SERIALIZATION AND PRECOMPILING
It is possible to save compiled patterns on disc or elsewhere, and
- reload them later, subject to a number of restrictions. The functions
- whose names begin with pcre2_serialize_ are used for this purpose. They
- are described in the pcre2serialize documentation.
+ reload them later, subject to a number of restrictions. The host on
+ which the patterns are reloaded must be running the same version of
+ PCRE2, with the same code unit width, and must also have the same endi-
+ anness, pointer width, and PCRE2_SIZE type. Before compiled patterns
+ can be saved, they must be converted to a "serialized" form, which in
+ the case of PCRE2 is really just a bytecode dump. The functions whose
+ names begin with pcre2_serialize_ are used for converting to and from
+ the serialized form. They are described in the pcre2serialize documen-
+ tation. Note that PCRE2 serialization does not convert compiled pat-
+ terns to an abstract format like Java or .NET serialization.
THE MATCH DATA BLOCK
@@ -2275,56 +2282,56 @@
void pcre2_match_data_free(pcre2_match_data *match_data);
- Information about a successful or unsuccessful match is placed in a
- match data block, which is an opaque structure that is accessed by
- function calls. In particular, the match data block contains a vector
- of offsets into the subject string that define the matched part of the
- subject and any substrings that were captured. This is known as the
+ Information about a successful or unsuccessful match is placed in a
+ match data block, which is an opaque structure that is accessed by
+ function calls. In particular, the match data block contains a vector
+ of offsets into the subject string that define the matched part of the
+ subject and any substrings that were captured. This is known as the
ovector.
- Before calling pcre2_match(), pcre2_dfa_match(), or pcre2_jit_match()
+ Before calling pcre2_match(), pcre2_dfa_match(), or pcre2_jit_match()
you must create a match data block by calling one of the creation func-
- tions above. For pcre2_match_data_create(), the first argument is the
- number of pairs of offsets in the ovector. One pair of offsets is
+ tions above. For pcre2_match_data_create(), the first argument is the
+ number of pairs of offsets in the ovector. One pair of offsets is
required to identify the string that matched the whole pattern, with an
- additional pair for each captured substring. For example, a value of 4
- creates enough space to record the matched portion of the subject plus
- three captured substrings. A minimum of at least 1 pair is imposed by
+ additional pair for each captured substring. For example, a value of 4
+ creates enough space to record the matched portion of the subject plus
+ three captured substrings. A minimum of at least 1 pair is imposed by
pcre2_match_data_create(), so it is always possible to return the over-
all matched string.
The second argument of pcre2_match_data_create() is a pointer to a gen-
- eral context, which can specify custom memory management for obtaining
+ eral context, which can specify custom memory management for obtaining
the memory for the match data block. If you are not using custom memory
management, pass NULL, which causes malloc() to be used.
- For pcre2_match_data_create_from_pattern(), the first argument is a
+ For pcre2_match_data_create_from_pattern(), the first argument is a
pointer to a compiled pattern. The ovector is created to be exactly the
right size to hold all the substrings a pattern might capture. The sec-
- ond argument is again a pointer to a general context, but in this case
+ ond argument is again a pointer to a general context, but in this case
if NULL is passed, the memory is obtained using the same allocator that
was used for the compiled pattern (custom or default).
- A match data block can be used many times, with the same or different
- compiled patterns. You can extract information from a match data block
+ A match data block can be used many times, with the same or different
+ compiled patterns. You can extract information from a match data block
after a match operation has finished, using functions that are
- described in the sections on matched strings and other match data
+ described in the sections on matched strings and other match data
below.
- When a call of pcre2_match() fails, valid data is available in the
- match block only when the error is PCRE2_ERROR_NOMATCH,
- PCRE2_ERROR_PARTIAL, or one of the error codes for an invalid UTF
+ When a call of pcre2_match() fails, valid data is available in the
+ match block only when the error is PCRE2_ERROR_NOMATCH,
+ PCRE2_ERROR_PARTIAL, or one of the error codes for an invalid UTF
string. Exactly what is available depends on the error, and is detailed
below.
- 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 match data block (for that match) have
+ 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 match data block (for that match) have
taken place.
- When a match data block itself is no longer needed, it should be freed
+ When a match data block itself is no longer needed, it should be freed
by calling pcre2_match_data_free().
@@ -2335,15 +2342,15 @@
uint32_t options, pcre2_match_data *match_data,
pcre2_match_context *mcontext);
- The function pcre2_match() is called to match a subject string against
- a compiled pattern, which is passed in the code argument. You can call
+ The function pcre2_match() is called to match a subject string against
+ a compiled pattern, which is passed in the code argument. You can call
pcre2_match() with the same code argument as many times as you like, in
- order to find multiple matches in the subject string or to match dif-
+ order to find multiple matches in the subject string or to match dif-
ferent subject strings with the same pattern.
- This function is the main matching facility of the library, and it
- operates in a Perl-like manner. For specialist use there is also an
- alternative matching function, which is described below in the section
+ This function is the main matching facility of the library, and it
+ operates in a Perl-like manner. For specialist use there is also an
+ alternative matching function, which is described below in the section
about the pcre2_dfa_match() function.
Here is an example of a simple call to pcre2_match():
@@ -2358,7 +2365,7 @@
md, /* the match data block */
NULL); /* a match context; NULL means use defaults */
- If the subject string is zero-terminated, the length can be given as
+ If the subject string is zero-terminated, the length can be given as
PCRE2_ZERO_TERMINATED. A match context must be provided if certain less
common matching parameters are to be changed. For details, see the sec-
tion on the match context above.
@@ -2365,92 +2372,92 @@
The string to be matched by pcre2_match()
- The subject string is passed to pcre2_match() as a pointer in subject,
- a length in length, and a starting offset in startoffset. The length
- and offset are in code units, not characters. That is, they are in
- bytes for the 8-bit library, 16-bit code units for the 16-bit library,
- and 32-bit code units for the 32-bit library, whether or not UTF pro-
+ The subject string is passed to pcre2_match() as a pointer in subject,
+ a length in length, and a starting offset in startoffset. The length
+ and offset are in code units, not characters. That is, they are in
+ bytes for the 8-bit library, 16-bit code units for the 16-bit library,
+ and 32-bit code units for the 32-bit library, whether or not UTF pro-
cessing is enabled.
If startoffset is greater than the length of the subject, pcre2_match()
- returns PCRE2_ERROR_BADOFFSET. When the starting offset is zero, the
- search for a match starts at the beginning of the subject, and this is
+ returns PCRE2_ERROR_BADOFFSET. When the starting offset is zero, the
+ search for a match starts at the beginning of the subject, and this is
by far the most common case. In UTF-8 or UTF-16 mode, the starting off-
- set must point to the start of a character, or to the end of the sub-
- ject (in UTF-32 mode, one code unit equals one character, so all off-
- sets are valid). Like the pattern string, the subject may contain
+ set must point to the start of a character, or to the end of the sub-
+ ject (in UTF-32 mode, one code unit equals one character, so all off-
+ sets are valid). Like the pattern string, the subject may contain
binary zeros.
- A non-zero starting offset is useful when searching for another match
- in the same subject by calling pcre2_match() again after a previous
- success. Setting startoffset differs from passing over a shortened
- string and setting PCRE2_NOTBOL in the case of a pattern that begins
+ A non-zero starting offset is useful when searching for another match
+ in the same subject by calling pcre2_match() again after a previous
+ success. Setting startoffset differs from passing over a shortened
+ string and setting PCRE2_NOTBOL in the case of a pattern that begins
with any kind of lookbehind. For example, consider the pattern
\Biss\B
- which finds occurrences of "iss" in the middle of words. (\B matches
- only if the current position in the subject is not a word boundary.)
+ which finds occurrences of "iss" in the middle of words. (\B matches
+ only if the current position in the subject is not a word boundary.)
When applied to the string "Mississipi" the first call to pcre2_match()
- finds the first occurrence. If pcre2_match() is called again with just
- the remainder of the subject, namely "issipi", it does not match,
+ finds the first occurrence. If pcre2_match() is called again with just
+ the remainder of the subject, namely "issipi", it does not match,
because \B is always false at the start of the subject, which is deemed
- to be a word boundary. However, if pcre2_match() is passed the entire
+ to be a word boundary. However, if pcre2_match() is passed the entire
string again, but with startoffset set to 4, it finds the second occur-
- rence of "iss" because it is able to look behind the starting point to
+ rence of "iss" because it is able to look behind the starting point to
discover that it is preceded by a letter.
- Finding all the matches in a subject is tricky when the pattern can
+ Finding all the matches in a subject is tricky when the pattern can
match an empty string. It is possible to emulate Perl's /g behaviour by
- first trying the match again at the same offset, with the
- PCRE2_NOTEMPTY_ATSTART and PCRE2_ANCHORED options, and then if that
- fails, advancing the starting offset and trying an ordinary match
- again. There is some code that demonstrates how to do this in the
- pcre2demo sample program. In the most general case, you have to check
- to see if the newline convention recognizes CRLF as a newline, and if
- so, and the current character is CR followed by LF, advance the start-
+ first trying the match again at the same offset, with the
+ PCRE2_NOTEMPTY_ATSTART and PCRE2_ANCHORED options, and then if that
+ fails, advancing the starting offset and trying an ordinary match
+ again. There is some code that demonstrates how to do this in the
+ pcre2demo sample program. In the most general case, you have to check
+ to see if the newline convention recognizes CRLF as a newline, and if
+ so, and the current character is CR followed by LF, advance the start-
ing offset by two characters instead of one.
If a non-zero starting offset is passed when the pattern is anchored, a
single attempt to match at the given offset is made. This can only suc-
- ceed if the pattern does not require the match to be at the start of
- the subject. In other words, the anchoring must be the result of set-
- ting the PCRE2_ANCHORED option or the use of .* with PCRE2_DOTALL, not
+ ceed if the pattern does not require the match to be at the start of
+ the subject. In other words, the anchoring must be the result of set-
+ ting the PCRE2_ANCHORED option or the use of .* with PCRE2_DOTALL, not
by starting the pattern with ^ or \A.
Option bits for pcre2_match()
The unused bits of the options argument for pcre2_match() must be zero.
- The only bits that may be set are PCRE2_ANCHORED, PCRE2_ENDANCHORED,
- PCRE2_NOTBOL, PCRE2_NOTEOL, PCRE2_NOTEMPTY, PCRE2_NOTEMPTY_ATSTART,
- PCRE2_NO_JIT, PCRE2_NO_UTF_CHECK, PCRE2_PARTIAL_HARD, and PCRE2_PAR-
+ The only bits that may be set are PCRE2_ANCHORED, PCRE2_ENDANCHORED,
+ PCRE2_NOTBOL, PCRE2_NOTEOL, PCRE2_NOTEMPTY, PCRE2_NOTEMPTY_ATSTART,
+ PCRE2_NO_JIT, PCRE2_NO_UTF_CHECK, PCRE2_PARTIAL_HARD, and PCRE2_PAR-
TIAL_SOFT. Their action is described below.
- Setting PCRE2_ANCHORED or PCRE2_ENDANCHORED at match time is not sup-
- ported by the just-in-time (JIT) compiler. If it is set, JIT matching
- is disabled and the interpretive code in pcre2_match() is run. Apart
- from PCRE2_NO_JIT (obviously), the remaining options are supported for
+ Setting PCRE2_ANCHORED or PCRE2_ENDANCHORED at match time is not sup-
+ ported by the just-in-time (JIT) compiler. If it is set, JIT matching
+ is disabled and the interpretive code in pcre2_match() is run. Apart
+ from PCRE2_NO_JIT (obviously), the remaining options are supported for
JIT matching.
PCRE2_ANCHORED
The PCRE2_ANCHORED option limits pcre2_match() to matching at the first
- matching position. If a pattern was compiled with PCRE2_ANCHORED, or
- turned out to be anchored by virtue of its contents, it cannot be made
- unachored at matching time. Note that setting the option at match time
+ matching position. If a pattern was compiled with PCRE2_ANCHORED, or
+ turned out to be anchored by virtue of its contents, it cannot be made
+ unachored at matching time. Note that setting the option at match time
disables JIT matching.
PCRE2_ENDANCHORED
- If the PCRE2_ENDANCHORED option is set, any string that pcre2_match()
- matches must be right at the end of the subject string. Note that set-
+ If the PCRE2_ENDANCHORED option is set, any string that pcre2_match()
+ matches must be right at the end of the subject string. Note that set-
ting the option at match time disables JIT matching.
PCRE2_NOTBOL
This option specifies that first character of the subject string is not
- the beginning of a line, so the circumflex metacharacter should not
- match before it. Setting this without having set PCRE2_MULTILINE at
+ the beginning of a line, so the circumflex metacharacter should not
+ match before it. Setting this without having set PCRE2_MULTILINE at
compile time causes circumflex never to match. This option affects only
the behaviour of the circumflex metacharacter. It does not affect \A.
@@ -2457,9 +2464,9 @@
PCRE2_NOTEOL
This option specifies that the end of the subject string is not the end
- of a line, so the dollar metacharacter should not match it nor (except
- in multiline mode) a newline immediately before it. Setting this with-
- out having set PCRE2_MULTILINE at compile time causes dollar never to
+ of a line, so the dollar metacharacter should not match it nor (except
+ in multiline mode) a newline immediately before it. Setting this with-
+ out having set PCRE2_MULTILINE at compile time causes dollar never to
match. This option affects only the behaviour of the dollar metacharac-
ter. It does not affect \Z or \z.
@@ -2466,79 +2473,79 @@
PCRE2_NOTEMPTY
An empty string is not considered to be a valid match if this option is
- set. If there are alternatives in the pattern, they are tried. If all
- the alternatives match the empty string, the entire match fails. For
+ set. If there are alternatives in the pattern, they are tried. If all
+ the alternatives match the empty string, the entire match fails. For
example, if the pattern
a?b?
- is applied to a string not beginning with "a" or "b", it matches an
+ is applied to a string not beginning with "a" or "b", it matches an
empty string at the start of the subject. With PCRE2_NOTEMPTY set, this
- match is not valid, so pcre2_match() searches further into the string
+ match is not valid, so pcre2_match() searches further into the string
for occurrences of "a" or "b".
PCRE2_NOTEMPTY_ATSTART
- This is like PCRE2_NOTEMPTY, except that it locks out an empty string
+ This is like PCRE2_NOTEMPTY, except that it locks out an empty string
match only at the first matching position, that is, at the start of the
- subject plus the starting offset. An empty string match later in the
- subject is permitted. If the pattern is anchored, such a match can
+ subject plus the starting offset. An empty string match later in the
+ subject is permitted. If the pattern is anchored, such a match can
occur only if the pattern contains \K.
PCRE2_NO_JIT
- By default, if a pattern has been successfully processed by
- pcre2_jit_compile(), JIT is automatically used when pcre2_match() is
- called with options that JIT supports. Setting PCRE2_NO_JIT disables
+ By default, if a pattern has been successfully processed by
+ pcre2_jit_compile(), JIT is automatically used when pcre2_match() is
+ called with options that JIT supports. Setting PCRE2_NO_JIT disables
the use of JIT; it forces matching to be done by the interpreter.
PCRE2_NO_UTF_CHECK
When PCRE2_UTF is set at compile time, the validity of the subject as a
- UTF string is checked by default when pcre2_match() is subsequently
- called. If a non-zero starting offset is given, the check is applied
- only to that part of the subject that could be inspected during match-
- ing, and there is a check that the starting offset points to the first
- code unit of a character or to the end of the subject. If there are no
- lookbehind assertions in the pattern, the check starts at the starting
- offset. Otherwise, it starts at the length of the longest lookbehind
+ UTF string is checked by default when pcre2_match() is subsequently
+ called. If a non-zero starting offset is given, the check is applied
+ only to that part of the subject that could be inspected during match-
+ ing, and there is a check that the starting offset points to the first
+ code unit of a character or to the end of the subject. If there are no
+ lookbehind assertions in the pattern, the check starts at the starting
+ offset. Otherwise, it starts at the length of the longest lookbehind
before the starting offset, or at the start of the subject if there are
- not that many characters before the starting offset. Note that the
+ not that many characters before the starting offset. Note that the
sequences \b and \B are one-character lookbehinds.
The check is carried out before any other processing takes place, and a
- negative error code is returned if the check fails. There are several
- UTF error codes for each code unit width, corresponding to different
- problems with the code unit sequence. There are discussions about the
- validity of UTF-8 strings, UTF-16 strings, and UTF-32 strings in the
+ negative error code is returned if the check fails. There are several
+ UTF error codes for each code unit width, corresponding to different
+ problems with the code unit sequence. There are discussions about the
+ validity of UTF-8 strings, UTF-16 strings, and UTF-32 strings in the
pcre2unicode page.
- If you know that your subject is valid, and you want to skip these
- checks for performance reasons, you can set the PCRE2_NO_UTF_CHECK
- option when calling pcre2_match(). You might want to do this for the
+ If you know that your subject is valid, and you want to skip these
+ checks for performance reasons, you can set the PCRE2_NO_UTF_CHECK
+ option when calling pcre2_match(). You might want to do this for the
second and subsequent calls to pcre2_match() if you are making repeated
calls to find other matches in the same subject string.
- Warning: When PCRE2_NO_UTF_CHECK is set, the effect of passing an
- invalid string as a subject, or an invalid value of startoffset, is
+ Warning: When PCRE2_NO_UTF_CHECK is set, the effect of passing an
+ invalid string as a subject, or an invalid value of startoffset, is
undefined. Your program may crash or loop indefinitely.
PCRE2_PARTIAL_HARD
PCRE2_PARTIAL_SOFT
- These options turn on the partial matching feature. A partial match
- occurs if the end of the subject string is reached successfully, but
- there are not enough subject characters to complete the match. If this
- happens when PCRE2_PARTIAL_SOFT (but not PCRE2_PARTIAL_HARD) is set,
- matching continues by testing any remaining alternatives. Only if no
- complete match can be found is PCRE2_ERROR_PARTIAL returned instead of
- PCRE2_ERROR_NOMATCH. In other words, PCRE2_PARTIAL_SOFT specifies that
- the caller is prepared to handle a partial match, but only if no com-
+ These options turn on the partial matching feature. A partial match
+ occurs if the end of the subject string is reached successfully, but
+ there are not enough subject characters to complete the match. If this
+ happens when PCRE2_PARTIAL_SOFT (but not PCRE2_PARTIAL_HARD) is set,
+ matching continues by testing any remaining alternatives. Only if no
+ complete match can be found is PCRE2_ERROR_PARTIAL returned instead of
+ PCRE2_ERROR_NOMATCH. In other words, PCRE2_PARTIAL_SOFT specifies that
+ the caller is prepared to handle a partial match, but only if no com-
plete match can be found.
- If PCRE2_PARTIAL_HARD is set, it overrides PCRE2_PARTIAL_SOFT. In this
- case, if a partial match is found, pcre2_match() immediately returns
- PCRE2_ERROR_PARTIAL, without considering any other alternatives. In
+ If PCRE2_PARTIAL_HARD is set, it overrides PCRE2_PARTIAL_SOFT. In this
+ case, if a partial match is found, pcre2_match() immediately returns
+ PCRE2_ERROR_PARTIAL, without considering any other alternatives. In
other words, when PCRE2_PARTIAL_HARD is set, a partial match is consid-
ered to be more important that an alternative complete match.
@@ -2548,38 +2555,38 @@
NEWLINE HANDLING WHEN MATCHING
- When PCRE2 is built, a default newline convention is set; this is usu-
- ally the standard convention for the operating system. The default can
- be overridden in a compile context by calling pcre2_set_newline(). It
- can also be overridden by starting a pattern string with, for example,
- (*CRLF), as described in the section on newline conventions in the
- pcre2pattern page. During matching, the newline choice affects the be-
- haviour of the dot, circumflex, and dollar metacharacters. It may also
- alter the way the match starting position is advanced after a match
+ When PCRE2 is built, a default newline convention is set; this is usu-
+ ally the standard convention for the operating system. The default can
+ be overridden in a compile context by calling pcre2_set_newline(). It
+ can also be overridden by starting a pattern string with, for example,
+ (*CRLF), as described in the section on newline conventions in the
+ pcre2pattern page. During matching, the newline choice affects the be-
+ haviour of the dot, circumflex, and dollar metacharacters. It may also
+ alter the way the match starting position is advanced after a match
failure for an unanchored pattern.
When PCRE2_NEWLINE_CRLF, PCRE2_NEWLINE_ANYCRLF, or PCRE2_NEWLINE_ANY is
- set as the newline convention, and a match attempt for an unanchored
+ set as the newline convention, and a match attempt for an unanchored
pattern fails when the current starting position is at a CRLF sequence,
- and the pattern contains no explicit matches for CR or LF characters,
- the match position is advanced by two characters instead of one, in
+ and the pattern contains no explicit matches for CR or LF characters,
+ the match position is advanced by two characters instead of one, in
other words, to after the CRLF.
The above rule is a compromise that makes the most common cases work as
- expected. For example, if the pattern is .+A (and the PCRE2_DOTALL
+ expected. For example, if the pattern is .+A (and the PCRE2_DOTALL
option is not set), it does not match the string "\r\nA" because, after
- failing at the start, it skips both the CR and the LF before retrying.
- However, the pattern [\r\n]A does match that string, because it con-
+ failing at the start, it skips both the CR and the LF before retrying.
+ However, the pattern [\r\n]A does match that string, because it con-
tains an explicit CR or LF reference, and so advances only by one char-
acter after the first failure.
An explicit match for CR of LF is either a literal appearance of one of
- those characters in the pattern, or one of the \r or \n or equivalent
+ those characters in the pattern, or one of the \r or \n or equivalent
octal or hexadecimal escape sequences. Implicit matches such as [^X] do
- not count, nor does \s, even though it includes CR and LF in the char-
+ not count, nor does \s, even though it includes CR and LF in the char-
acters that it matches.
- Notwithstanding the above, anomalous effects may still occur when CRLF
+ Notwithstanding the above, anomalous effects may still occur when CRLF
is a valid newline sequence and explicit \r or \n escapes appear in the
pattern.
@@ -2590,81 +2597,81 @@
PCRE2_SIZE *pcre2_get_ovector_pointer(pcre2_match_data *match_data);
- In general, a pattern matches a certain portion of the subject, and in
- addition, further substrings from the subject may be picked out by
- parenthesized parts of the pattern. Following the usage in Jeffrey
- Friedl's book, this is called "capturing" in what follows, and the
- phrase "capturing subpattern" or "capturing group" is used for a frag-
- ment of a pattern that picks out a substring. PCRE2 supports several
+ In general, a pattern matches a certain portion of the subject, and in
+ addition, further substrings from the subject may be picked out by
+ parenthesized parts of the pattern. Following the usage in Jeffrey
+ Friedl's book, this is called "capturing" in what follows, and the
+ phrase "capturing subpattern" or "capturing group" is used for a frag-
+ ment of a pattern that picks out a substring. PCRE2 supports several
other kinds of parenthesized subpattern that do not cause substrings to
- be captured. The pcre2_pattern_info() function can be used to find out
+ be captured. The pcre2_pattern_info() function can be used to find out
how many capturing subpatterns there are in a compiled pattern.
- You can use auxiliary functions for accessing captured substrings by
+ You can use auxiliary functions for accessing captured substrings by
number or by name, as described in sections below.
Alternatively, you can make direct use of the vector of PCRE2_SIZE val-
- ues, called the ovector, which contains the offsets of captured
- strings. It is part of the match data block. The function
- pcre2_get_ovector_pointer() returns the address of the ovector, and
+ ues, called the ovector, which contains the offsets of captured
+ strings. It is part of the match data block. The function
+ pcre2_get_ovector_pointer() returns the address of the ovector, and
pcre2_get_ovector_count() returns the number of pairs of values it con-
tains.
Within the ovector, the first in each pair of values is set to the off-
set of the first code unit of a substring, and the second is set to the
- offset of the first code unit after the end of a substring. These val-
- ues are always code unit offsets, not character offsets. That is, they
- are byte offsets in the 8-bit library, 16-bit offsets in the 16-bit
+ offset of the first code unit after the end of a substring. These val-
+ ues are always code unit offsets, not character offsets. That is, they
+ are byte offsets in the 8-bit library, 16-bit offsets in the 16-bit
library, and 32-bit offsets in the 32-bit library.
- After a partial match (error return PCRE2_ERROR_PARTIAL), only the
- first pair of offsets (that is, ovector[0] and ovector[1]) are set.
- They identify the part of the subject that was partially matched. See
+ After a partial match (error return PCRE2_ERROR_PARTIAL), only the
+ first pair of offsets (that is, ovector[0] and ovector[1]) are set.
+ They identify the part of the subject that was partially matched. See
the pcre2partial documentation for details of partial matching.
- After a fully successful match, the first pair of offsets identifies
- the portion of the subject string that was matched by the entire pat-
- tern. The next pair is used for the first captured substring, and so
- on. The value returned by pcre2_match() is one more than the highest
- numbered pair that has been set. For example, if two substrings have
- been captured, the returned value is 3. If there are no captured sub-
+ After a fully successful match, the first pair of offsets identifies
+ the portion of the subject string that was matched by the entire pat-
+ tern. The next pair is used for the first captured substring, and so
+ on. The value returned by pcre2_match() is one more than the highest
+ numbered pair that has been set. For example, if two substrings have
+ been captured, the returned value is 3. If there are no captured sub-
strings, the return value from a successful match is 1, indicating that
just the first pair of offsets has been set.
- If a pattern uses the \K escape sequence within a positive assertion,
+ If a pattern uses the \K escape sequence within a positive assertion,
the reported start of a successful match can be greater than the end of
- the match. For example, if the pattern (?=ab\K) is matched against
+ the match. For example, if the pattern (?=ab\K) is matched against
"ab", the start and end offset values for the match are 2 and 0.
- If a capturing subpattern group is matched repeatedly within a single
- match operation, it is the last portion of the subject that it matched
+ If a capturing subpattern group is matched repeatedly within a single
+ match operation, it is the last portion of the subject that it matched
that is returned.
If the ovector is too small to hold all the captured substring offsets,
- as much as possible is filled in, and the function returns a value of
- zero. If captured substrings are not of interest, pcre2_match() may be
+ as much as possible is filled in, and the function returns a value of
+ zero. If captured substrings are not of interest, pcre2_match() may be
called with a match data block whose ovector is of minimum length (that
is, one pair).
- It is possible for capturing subpattern number n+1 to match some part
+ It is possible for capturing subpattern number n+1 to match some part
of the subject when subpattern n has not been used at all. For example,
- if the string "abc" is matched against the pattern (a|(z))(bc) the
+ if the string "abc" is matched against the pattern (a|(z))(bc) the
return from the function is 4, and subpatterns 1 and 3 are matched, but
- 2 is not. When this happens, both values in the offset pairs corre-
+ 2 is not. When this happens, both values in the offset pairs corre-
sponding to unused subpatterns are set to PCRE2_UNSET.
- Offset values that correspond to unused subpatterns at the end of the
- expression are also set to PCRE2_UNSET. For example, if the string
+ Offset values that correspond to unused subpatterns at the end of the
+ expression are also set to PCRE2_UNSET. For example, if the string
"abc" is matched against the pattern (abc)(x(yz)?)? subpatterns 2 and 3
- are not matched. The return from the function is 2, because the high-
+ are not matched. The return from the function is 2, because the high-
est used capturing subpattern number is 1. The offsets for for the sec-
- ond and third capturing subpatterns (assuming the vector is large
+ ond and third capturing subpatterns (assuming the vector is large
enough, of course) are set to PCRE2_UNSET.
Elements in the ovector that do not correspond to capturing parentheses
in the pattern are never changed. That is, if a pattern contains n cap-
turing parentheses, no more than ovector[0] to ovector[2n+1] are set by
- pcre2_match(). The other elements retain whatever values they previ-
+ pcre2_match(). The other elements retain whatever values they previ-
ously had.
@@ -2674,55 +2681,55 @@
PCRE2_SIZE pcre2_get_startchar(pcre2_match_data *match_data);
- As well as the offsets in the ovector, other information about a match
- is retained in the match data block and can be retrieved by the above
- functions in appropriate circumstances. If they are called at other
+ As well as the offsets in the ovector, other information about a match
+ is retained in the match data block and can be retrieved by the above
+ functions in appropriate circumstances. If they are called at other
times, the result is undefined.
- After a successful match, a partial match (PCRE2_ERROR_PARTIAL), or a
+ After a successful match, a partial match (PCRE2_ERROR_PARTIAL), or a
failure to match (PCRE2_ERROR_NOMATCH), a (*MARK), (*PRUNE), or (*THEN)
- name may be available. The function pcre2_get_mark() can be called to
- access this name. The same function applies to all three verbs. It
+ name may be available. The function pcre2_get_mark() can be called to
+ access this name. The same function applies to all three verbs. It
returns a pointer to the zero-terminated name, which is within the com-
piled pattern. If no name is available, NULL is returned. The length of
- the name (excluding the terminating zero) is stored in the code unit
- that precedes the name. You should use this length instead of relying
+ the name (excluding the terminating zero) is stored in the code unit
+ that precedes the name. You should use this length instead of relying
on the terminating zero if the name might contain a binary zero.
- After a successful match, the name that is returned is the last
- (*MARK), (*PRUNE), or (*THEN) name encountered on the matching path
- through the pattern. Instances of (*PRUNE) and (*THEN) without names
- are ignored. Thus, for example, if the matching path contains
- (*MARK:A)(*PRUNE), the name "A" is returned. After a "no match" or a
- partial match, the last encountered name is returned. For example,
+ After a successful match, the name that is returned is the last
+ (*MARK), (*PRUNE), or (*THEN) name encountered on the matching path
+ through the pattern. Instances of (*PRUNE) and (*THEN) without names
+ are ignored. Thus, for example, if the matching path contains
+ (*MARK:A)(*PRUNE), the name "A" is returned. After a "no match" or a
+ partial match, the last encountered name is returned. For example,
consider this pattern:
^(*MARK:A)((*MARK:B)a|b)c
- When it matches "bc", the returned name is A. The B mark is "seen" in
- the first branch of the group, but it is not on the matching path. On
- the other hand, when this pattern fails to match "bx", the returned
+ When it matches "bc", the returned name is A. The B mark is "seen" in
+ the first branch of the group, but it is not on the matching path. On
+ the other hand, when this pattern fails to match "bx", the returned
name is B.
- Warning: By default, certain start-of-match optimizations are used to
- give a fast "no match" result in some situations. For example, if the
- anchoring is removed from the pattern above, there is an initial check
- for the presence of "c" in the subject before running the matching
+ Warning: By default, certain start-of-match optimizations are used to
+ give a fast "no match" result in some situations. For example, if the
+ anchoring is removed from the pattern above, there is an initial check
+ for the presence of "c" in the subject before running the matching
engine. This check fails for "bx", causing a match failure without see-
ing any marks. You can disable the start-of-match optimizations by set-
ting the PCRE2_NO_START_OPTIMIZE option for pcre2_compile() or starting
the pattern with (*NO_START_OPT).
- After a successful match, a partial match, or one of the invalid UTF
- errors (for example, PCRE2_ERROR_UTF8_ERR5), pcre2_get_startchar() can
+ After a successful match, a partial match, or one of the invalid UTF
+ errors (for example, PCRE2_ERROR_UTF8_ERR5), pcre2_get_startchar() can
be called. After a successful or partial match it returns the code unit
- offset of the character at which the match started. For a non-partial
- match, this can be different to the value of ovector[0] if the pattern
- contains the \K escape sequence. After a partial match, however, this
- value is always the same as ovector[0] because \K does not affect the
+ offset of the character at which the match started. For a non-partial
+ match, this can be different to the value of ovector[0] if the pattern
+ contains the \K escape sequence. After a partial match, however, this
+ value is always the same as ovector[0] because \K does not affect the
result of a partial match.
- After a UTF check failure, pcre2_get_startchar() can be used to obtain
+ After a UTF check failure, pcre2_get_startchar() can be used to obtain
the code unit offset of the invalid UTF character. Details are given in
the pcre2unicode page.
@@ -2729,14 +2736,14 @@
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 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
+ If pcre2_match() fails, it returns a negative number. This can be con-
+ 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
+ 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
@@ -2745,20 +2752,20 @@
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 compiled pattern is passed to a function in
- a library of a different code unit width, for example, a pattern com-
- piled by the 8-bit library is passed to a 16-bit or 32-bit library
+ This error is given when a compiled pattern is passed to a function in
+ a library of a different code unit width, for example, a pattern com-
+ piled by the 8-bit library is passed to a 16-bit or 32-bit library
function.
PCRE2_ERROR_BADOFFSET
@@ -2772,15 +2779,15 @@
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_DEPTHLIMIT
@@ -2793,14 +2800,14 @@
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_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
@@ -2809,10 +2816,10 @@
PCRE2_ERROR_NOMEMORY
- If a pattern contains many nested backtracking points, heap memory is
- used to remember them. This error is given when the memory allocation
- function (default or custom) fails. Note that a different error,
- PCRE2_ERROR_HEAPLIMIT, is given if the amount of memory needed exceeds
+ If a pattern contains many nested backtracking points, heap memory is
+ used to remember them. This error is given when the memory allocation
+ function (default or custom) fails. Note that a different error,
+ PCRE2_ERROR_HEAPLIMIT, is given if the amount of memory needed exceeds
the heap limit.
PCRE2_ERROR_NULL
@@ -2821,12 +2828,12 @@
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.
@@ -2835,20 +2842,20 @@
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 in code
- units, into which the text message is placed. The message is returned
- in code units of the appropriate width for the library that is being
+ 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 in code
+ units, into which the text message is placed. 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
+ 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
+ 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.
@@ -2867,39 +2874,39 @@
void pcre2_substring_free(PCRE2_UCHAR *buffer);
- Captured substrings can be accessed directly by using the ovector as
+ Captured substrings can be accessed directly by using the ovector as
described above. For convenience, auxiliary functions are provided for
- extracting captured substrings as new, separate, zero-terminated
+ extracting captured substrings as new, separate, zero-terminated
strings. A substring that contains a binary zero is correctly extracted
- and has a further zero added on the end, but the result is not, of
+ and has a further zero added on the end, but the result is not, of
course, a C string.
The functions in this section identify substrings by number. The number
zero refers to the entire matched substring, with higher numbers refer-
- ring to substrings captured by parenthesized groups. After a partial
- match, only substring zero is available. An attempt to extract any
- other substring gives the error PCRE2_ERROR_PARTIAL. The next section
+ ring to substrings captured by parenthesized groups. After a partial
+ match, only substring zero is available. An attempt to extract any
+ other substring gives the error PCRE2_ERROR_PARTIAL. The next section
describes similar functions for extracting captured substrings by name.
- If a pattern uses the \K escape sequence within a positive assertion,
+ If a pattern uses the \K escape sequence within a positive assertion,
the reported start of a successful match can be greater than the end of
- the match. For example, if the pattern (?=ab\K) is matched against
- "ab", the start and end offset values for the match are 2 and 0. In
- this situation, calling these functions with a zero substring number
+ the match. For example, if the pattern (?=ab\K) is matched against
+ "ab", the start and end offset values for the match are 2 and 0. In
+ this situation, calling these functions with a zero substring number
extracts a zero-length empty string.
- You can find the length in code units of a captured substring without
- extracting it by calling pcre2_substring_length_bynumber(). The first
- argument is a pointer to the match data block, the second is the group
- number, and the third is a pointer to a variable into which the length
- is placed. If you just want to know whether or not the substring has
+ You can find the length in code units of a captured substring without
+ extracting it by calling pcre2_substring_length_bynumber(). The first
+ argument is a pointer to the match data block, the second is the group
+ number, and the third is a pointer to a variable into which the length
+ is placed. If you just want to know whether or not the substring has
been captured, you can pass the third argument as NULL.
- The pcre2_substring_copy_bynumber() function copies a captured sub-
- string into a supplied buffer, whereas pcre2_substring_get_bynumber()
- copies it into new memory, obtained using the same memory allocation
- function that was used for the match data block. The first two argu-
- ments of these functions are a pointer to the match data block and a
+ The pcre2_substring_copy_bynumber() function copies a captured sub-
+ string into a supplied buffer, whereas pcre2_substring_get_bynumber()
+ copies it into new memory, obtained using the same memory allocation
+ function that was used for the match data block. The first two argu-
+ ments of these functions are a pointer to the match data block and a
capturing group number.
The final arguments of pcre2_substring_copy_bynumber() are a pointer to
@@ -2908,25 +2915,25 @@
for the extracted substring, excluding the terminating zero.
For pcre2_substring_get_bynumber() the third and fourth arguments point
- to variables that are updated with a pointer to the new memory and the
- number of code units that comprise the substring, again excluding the
- terminating zero. When the substring is no longer needed, the memory
+ to variables that are updated with a pointer to the new memory and the
+ number of code units that comprise the substring, again excluding the
+ terminating zero. When the substring is no longer needed, the memory
should be freed by calling pcre2_substring_free().
- The return value from all these functions is zero for success, or a
- negative error code. If the pattern match failed, the match failure
- code is returned. If a substring number greater than zero is used
- after a partial match, PCRE2_ERROR_PARTIAL is returned. Other possible
+ The return value from all these functions is zero for success, or a
+ negative error code. If the pattern match failed, the match failure
+ code is returned. If a substring number greater than zero is used
+ after a partial match, PCRE2_ERROR_PARTIAL is returned. Other possible
error codes are:
PCRE2_ERROR_NOMEMORY
- The buffer was too small for pcre2_substring_copy_bynumber(), or the
+ The buffer was too small for pcre2_substring_copy_bynumber(), or the
attempt to get memory failed for pcre2_substring_get_bynumber().
PCRE2_ERROR_NOSUBSTRING
- There is no substring with that number in the pattern, that is, the
+ There is no substring with that number in the pattern, that is, the
number is greater than the number of capturing parentheses.
PCRE2_ERROR_UNAVAILABLE
@@ -2937,8 +2944,8 @@
PCRE2_ERROR_UNSET
- The substring did not participate in the match. For example, if the
- pattern is (abc)|(def) and the subject is "def", and the ovector con-
+ The substring did not participate in the match. For example, if the
+ pattern is (abc)|(def) and the subject is "def", and the ovector con-
tains at least two capturing slots, substring number 1 is unset.
@@ -2949,32 +2956,32 @@
void pcre2_substring_list_free(PCRE2_SPTR *list);
- The pcre2_substring_list_get() function extracts all available sub-
- strings and builds a list of pointers to them. It also (optionally)
- builds a second list that contains their lengths (in code units),
+ The pcre2_substring_list_get() function extracts all available sub-
+ strings and builds a list of pointers to them. It also (optionally)
+ builds a second list that contains their lengths (in code units),
excluding a terminating zero that is added to each of them. All this is
done in a single block of memory that is obtained using the same memory
allocation function that was used to get the match data block.
- This function must be called only after a successful match. If called
+ This function must be called only after a successful match. If called
after a partial match, the error code PCRE2_ERROR_PARTIAL is returned.
- The address of the memory block is returned via listptr, which is also
+ The address of the memory block is returned via listptr, which is also
the start of the list of string pointers. The end of the list is marked
- by a NULL pointer. The address of the list of lengths is returned via
- lengthsptr. If your strings do not contain binary zeros and you do not
+ by a NULL pointer. The address of the list of lengths is returned via
+ lengthsptr. If your strings do not contain binary zeros and you do not
therefore need the lengths, you may supply NULL as the lengthsptr argu-
- ment to disable the creation of a list of lengths. The yield of the
- function is zero if all went well, or PCRE2_ERROR_NOMEMORY if the mem-
- ory block could not be obtained. When the list is no longer needed, it
+ ment to disable the creation of a list of lengths. The yield of the
+ function is zero if all went well, or PCRE2_ERROR_NOMEMORY if the mem-
+ ory block could not be obtained. When the list is no longer needed, it
should be freed by calling pcre2_substring_list_free().
If this function encounters a substring that is unset, which can happen
- when capturing subpattern number n+1 matches some part of the subject,
- but subpattern n has not been used at all, it returns an empty string.
- This can be distinguished from a genuine zero-length substring by
+ when capturing subpattern number n+1 matches some part of the subject,
+ but subpattern n has not been used at all, it returns an empty string.
+ This can be distinguished from a genuine zero-length substring by
inspecting the appropriate offset in the ovector, which contain
- PCRE2_UNSET for unset substrings, or by calling pcre2_sub-
+ PCRE2_UNSET for unset substrings, or by calling pcre2_sub-
string_length_bynumber().
@@ -2994,39 +3001,39 @@
void pcre2_substring_free(PCRE2_UCHAR *buffer);
- To extract a substring by name, you first have to find associated num-
+ To extract a substring by name, you first have to find associated num-
ber. For example, for this pattern:
(a+)b(?<xxx>\d+)...
the number of the subpattern called "xxx" is 2. If the name is known to
- be unique (PCRE2_DUPNAMES was not set), you can find the number from
+ be unique (PCRE2_DUPNAMES was not set), you can find the number from
the name by calling pcre2_substring_number_from_name(). The first argu-
- ment is the compiled pattern, and the second is the name. The yield of
+ ment is the compiled pattern, and the second is the name. The yield of
the function is the subpattern number, PCRE2_ERROR_NOSUBSTRING if there
- is no subpattern of that name, or PCRE2_ERROR_NOUNIQUESUBSTRING if
- there is more than one subpattern of that name. Given the number, you
- can extract the substring directly from the ovector, or use one of the
+ is no subpattern of that name, or PCRE2_ERROR_NOUNIQUESUBSTRING if
+ there is more than one subpattern of that name. Given the number, you
+ can extract the substring directly from the ovector, or use one of the
"bynumber" functions described above.
- For convenience, there are also "byname" functions that correspond to
- the "bynumber" functions, the only difference being that the second
- argument is a name instead of a number. If PCRE2_DUPNAMES is set and
+ For convenience, there are also "byname" functions that correspond to
+ the "bynumber" functions, the only difference being that the second
+ argument is a name instead of a number. If PCRE2_DUPNAMES is set and
there are duplicate names, these functions scan all the groups with the
given name, and return the first named string that is set.
- If there are no groups with the given name, PCRE2_ERROR_NOSUBSTRING is
- returned. If all groups with the name have numbers that are greater
- than the number of slots in the ovector, PCRE2_ERROR_UNAVAILABLE is
- returned. If there is at least one group with a slot in the ovector,
+ If there are no groups with the given name, PCRE2_ERROR_NOSUBSTRING is
+ returned. If all groups with the name have numbers that are greater
+ than the number of slots in the ovector, PCRE2_ERROR_UNAVAILABLE is
+ returned. If there is at least one group with a slot in the ovector,
but no group is found to be set, PCRE2_ERROR_UNSET is returned.
Warning: If the pattern uses the (?| feature to set up multiple subpat-
- terns with the same number, as described in the section on duplicate
- subpattern numbers in the pcre2pattern page, you cannot use names to
- distinguish the different subpatterns, because names are not included
- in the compiled code. The matching process uses only numbers. For this
- reason, the use of different names for subpatterns of the same number
+ terns with the same number, as described in the section on duplicate
+ subpattern numbers in the pcre2pattern page, you cannot use names to
+ distinguish the different subpatterns, because names are not included
+ in the compiled code. The matching process uses only numbers. For this
+ reason, the use of different names for subpatterns of the same number
causes an error at compile time.
@@ -3039,42 +3046,42 @@
PCRE2_SIZE rlength, PCRE2_UCHAR *outputbufferP,
PCRE2_SIZE *outlengthptr);
- This function calls pcre2_match() and then makes a copy of the subject
- string in outputbuffer, replacing the part that was matched with the
- replacement string, whose length is supplied in rlength. This can be
+ This function calls pcre2_match() and then makes a copy of the subject
+ string in outputbuffer, replacing the part that was matched with the
+ replacement string, whose length is supplied in rlength. This can be
given as PCRE2_ZERO_TERMINATED for a zero-terminated string. Matches in
- which a \K item in a lookahead in the pattern causes the match to end
+ which a \K item in a lookahead in the pattern causes the match to end
before it starts are not supported, and give rise to an error return.
- The first seven arguments of pcre2_substitute() are the same as for
+ The first seven arguments of pcre2_substitute() are the same as for
pcre2_match(), except that the partial matching options are not permit-
- ted, and match_data may be passed as NULL, in which case a match data
- block is obtained and freed within this function, using memory manage-
- ment functions from the match context, if provided, or else those that
+ ted, and match_data may be passed as NULL, in which case a match data
+ block is obtained and freed within this function, using memory manage-
+ ment functions from the match context, if provided, or else those that
were used to allocate memory for the compiled code.
- The outlengthptr argument must point to a variable that contains the
- length, in code units, of the output buffer. If the function is suc-
- cessful, the value is updated to contain the length of the new string,
+ The outlengthptr argument must point to a variable that contains the
+ length, in code units, of the output buffer. If the function is suc-
+ cessful, the value is updated to contain the length of the new string,
excluding the trailing zero that is automatically added.
- If the function is not successful, the value set via outlengthptr
- depends on the type of error. For syntax errors in the replacement
- string, the value is the offset in the replacement string where the
- error was detected. For other errors, the value is PCRE2_UNSET by
- default. This includes the case of the output buffer being too small,
- unless PCRE2_SUBSTITUTE_OVERFLOW_LENGTH is set (see below), in which
- case the value is the minimum length needed, including space for the
- trailing zero. Note that in order to compute the required length,
- pcre2_substitute() has to simulate all the matching and copying,
+ If the function is not successful, the value set via outlengthptr
+ depends on the type of error. For syntax errors in the replacement
+ string, the value is the offset in the replacement string where the
+ error was detected. For other errors, the value is PCRE2_UNSET by
+ default. This includes the case of the output buffer being too small,
+ unless PCRE2_SUBSTITUTE_OVERFLOW_LENGTH is set (see below), in which
+ case the value is the minimum length needed, including space for the
+ trailing zero. Note that in order to compute the required length,
+ pcre2_substitute() has to simulate all the matching and copying,
instead of giving an error return as soon as the buffer overflows. Note
also that the length is in code units, not bytes.
- In the replacement string, which is interpreted as a UTF string in UTF
- mode, and is checked for UTF validity unless the PCRE2_NO_UTF_CHECK
+ In the replacement string, which is interpreted as a UTF string in UTF
+ mode, and is checked for UTF validity unless the PCRE2_NO_UTF_CHECK
option is set, a dollar character is an escape character that can spec-
- ify the insertion of characters from capturing groups or (*MARK),
- (*PRUNE), or (*THEN) items in the pattern. The following forms are
+ ify the insertion of characters from capturing groups or (*MARK),
+ (*PRUNE), or (*THEN) items in the pattern. The following forms are
always recognized:
$$ insert a dollar character
@@ -3081,19 +3088,19 @@
$<n> or ${<n>} insert the contents of group <n>
$*MARK or ${*MARK} insert a (*MARK), (*PRUNE), or (*THEN) name
- Either a group number or a group name can be given for <n>. Curly
- brackets are required only if the following character would be inter-
+ Either a group number or a group name can be given for <n>. Curly
+ brackets are required only if the following character would be inter-
preted as part of the number or name. The number may be zero to include
- the entire matched string. For example, if the pattern a(b)c is
- matched with "=abc=" and the replacement string "+$1$0$1+", the result
+ the entire matched string. For example, if the pattern a(b)c is
+ matched with "=abc=" and the replacement string "+$1$0$1+", the result
is "=+babcb+=".
$*MARK inserts the name from the last encountered (*MARK), (*PRUNE), or
- (*THEN) on the matching path that has a name. (*MARK) must always
- include a name, but (*PRUNE) and (*THEN) need not. For example, in the
- case of (*MARK:A)(*PRUNE) the name inserted is "A", but for
- (*MARK:A)(*PRUNE:B) the relevant name is "B". This facility can be
- used to perform simple simultaneous substitutions, as this pcre2test
+ (*THEN) on the matching path that has a name. (*MARK) must always
+ include a name, but (*PRUNE) and (*THEN) need not. For example, in the
+ case of (*MARK:A)(*PRUNE) the name inserted is "A", but for
+ (*MARK:A)(*PRUNE:B) the relevant name is "B". This facility can be
+ used to perform simple simultaneous substitutions, as this pcre2test
example shows:
/(*MARK:pear)apple|(*MARK:orange)lemon/g,replace=${*MARK}
@@ -3100,19 +3107,19 @@
apple lemon
2: pear orange
- As well as the usual options for pcre2_match(), a number of additional
+ As well as the usual options for pcre2_match(), a number of additional
options can be set in the options argument of pcre2_substitute().
PCRE2_SUBSTITUTE_GLOBAL causes the function to iterate over the subject
- string, replacing every matching substring. If this option is not set,
- only the first matching substring is replaced. The search for matches
- takes place in the original subject string (that is, previous replace-
- ments do not affect it). Iteration is implemented by advancing the
- startoffset value for each search, which is always passed the entire
+ string, replacing every matching substring. If this option is not set,
+ only the first matching substring is replaced. The search for matches
+ takes place in the original subject string (that is, previous replace-
+ ments do not affect it). Iteration is implemented by advancing the
+ startoffset value for each search, which is always passed the entire
subject string. If an offset limit is set in the match context, search-
ing stops when that limit is reached.
- You can restrict the effect of a global substitution to a portion of
+ You can restrict the effect of a global substitution to a portion of
the subject string by setting either or both of startoffset and an off-
set limit. Here is a pcre2test example:
@@ -3120,87 +3127,87 @@
ABC ABC ABC ABC\=offset=3,offset_limit=12
2: ABC A!C A!C ABC
- When continuing with global substitutions after matching a substring
+ When continuing with global substitutions after matching a substring
with zero length, an attempt to find a non-empty match at the same off-
set is performed. If this is not successful, the offset is advanced by
one character except when CRLF is a valid newline sequence and the next
- two characters are CR, LF. In this case, the offset is advanced by two
+ two characters are CR, LF. In this case, the offset is advanced by two
characters.
- PCRE2_SUBSTITUTE_OVERFLOW_LENGTH changes what happens when the output
+ PCRE2_SUBSTITUTE_OVERFLOW_LENGTH changes what happens when the output
buffer is too small. The default action is to return PCRE2_ERROR_NOMEM-
- ORY immediately. If this option is set, however, pcre2_substitute()
+ ORY immediately. If this option is set, however, pcre2_substitute()
continues to go through the motions of matching and substituting (with-
- out, of course, writing anything) in order to compute the size of buf-
- fer that is needed. This value is passed back via the outlengthptr
- variable, with the result of the function still being
+ out, of course, writing anything) in order to compute the size of buf-
+ fer that is needed. This value is passed back via the outlengthptr
+ variable, with the result of the function still being
PCRE2_ERROR_NOMEMORY.
- Passing a buffer size of zero is a permitted way of finding out how
- much memory is needed for given substitution. However, this does mean
+ Passing a buffer size of zero is a permitted way of finding out how
+ much memory is needed for given substitution. However, this does mean
that the entire operation is carried out twice. Depending on the appli-
- cation, it may be more efficient to allocate a large buffer and free
- the excess afterwards, instead of using PCRE2_SUBSTITUTE_OVER-
+ cation, it may be more efficient to allocate a large buffer and free
+ the excess afterwards, instead of using PCRE2_SUBSTITUTE_OVER-
FLOW_LENGTH.
- PCRE2_SUBSTITUTE_UNKNOWN_UNSET causes references to capturing groups
- that do not appear in the pattern to be treated as unset groups. This
- option should be used with care, because it means that a typo in a
- group name or number no longer causes the PCRE2_ERROR_NOSUBSTRING
+ PCRE2_SUBSTITUTE_UNKNOWN_UNSET causes references to capturing groups
+ that do not appear in the pattern to be treated as unset groups. This
+ option should be used with care, because it means that a typo in a
+ group name or number no longer causes the PCRE2_ERROR_NOSUBSTRING
error.
- PCRE2_SUBSTITUTE_UNSET_EMPTY causes unset capturing groups (including
+ PCRE2_SUBSTITUTE_UNSET_EMPTY causes unset capturing groups (including
unknown groups when PCRE2_SUBSTITUTE_UNKNOWN_UNSET is set) to be
- treated as empty strings when inserted as described above. If this
- option is not set, an attempt to insert an unset group causes the
- PCRE2_ERROR_UNSET error. This option does not influence the extended
+ treated as empty strings when inserted as described above. If this
+ option is not set, an attempt to insert an unset group causes the
+ PCRE2_ERROR_UNSET error. This option does not influence the extended
substitution syntax described below.
- PCRE2_SUBSTITUTE_EXTENDED causes extra processing to be applied to the
- replacement string. Without this option, only the dollar character is
- special, and only the group insertion forms listed above are valid.
+ PCRE2_SUBSTITUTE_EXTENDED causes extra processing to be applied to the
+ replacement string. Without this option, only the dollar character is
+ special, and only the group insertion forms listed above are valid.
When PCRE2_SUBSTITUTE_EXTENDED is set, two things change:
- Firstly, backslash in a replacement string is interpreted as an escape
+ Firstly, backslash in a replacement string is interpreted as an escape
character. The usual forms such as \n or \x{ddd} can be used to specify
- particular character codes, and backslash followed by any non-alphanu-
- meric character quotes that character. Extended quoting can be coded
+ particular character codes, and backslash followed by any non-alphanu-
+ meric character quotes that character. Extended quoting can be coded
using \Q...\E, exactly as in pattern strings.
- There are also four escape sequences for forcing the case of inserted
- letters. The insertion mechanism has three states: no case forcing,
+ There are also four escape sequences for forcing the case of inserted
+ letters. The insertion mechanism has three states: no case forcing,
force upper case, and force lower case. The escape sequences change the
current state: \U and \L change to upper or lower case forcing, respec-
- tively, and \E (when not terminating a \Q quoted sequence) reverts to
- no case forcing. The sequences \u and \l force the next character (if
- it is a letter) to upper or lower case, respectively, and then the
+ tively, and \E (when not terminating a \Q quoted sequence) reverts to
+ no case forcing. The sequences \u and \l force the next character (if
+ it is a letter) to upper or lower case, respectively, and then the
state automatically reverts to no case forcing. Case forcing applies to
all inserted characters, including those from captured groups and let-
ters within \Q...\E quoted sequences.
Note that case forcing sequences such as \U...\E do not nest. For exam-
- ple, the result of processing "\Uaa\LBB\Ecc\E" is "AAbbcc"; the final
+ ple, the result of processing "\Uaa\LBB\Ecc\E" is "AAbbcc"; the final
\E has no effect.
- The second effect of setting PCRE2_SUBSTITUTE_EXTENDED is to add more
- flexibility to group substitution. The syntax is similar to that used
+ The second effect of setting PCRE2_SUBSTITUTE_EXTENDED is to add more
+ flexibility to group substitution. The syntax is similar to that used
by Bash:
${<n>:-<string>}
${<n>:+<string1>:<string2>}
- As before, <n> may be a group number or a name. The first form speci-
- fies a default value. If group <n> is set, its value is inserted; if
- not, <string> is expanded and the result inserted. The second form
- specifies strings that are expanded and inserted when group <n> is set
- or unset, respectively. The first form is just a convenient shorthand
+ As before, <n> may be a group number or a name. The first form speci-
+ fies a default value. If group <n> is set, its value is inserted; if
+ not, <string> is expanded and the result inserted. The second form
+ specifies strings that are expanded and inserted when group <n> is set
+ or unset, respectively. The first form is just a convenient shorthand
for
${<n>:+${<n>}:<string>}
- Backslash can be used to escape colons and closing curly brackets in
- the replacement strings. A change of the case forcing state within a
- replacement string remains in force afterwards, as shown in this
+ Backslash can be used to escape colons and closing curly brackets in
+ the replacement strings. A change of the case forcing state within a
+ replacement string remains in force afterwards, as shown in this
pcre2test example:
/(some)?(body)/substitute_extended,replace=${1:+\U:\L}HeLLo
@@ -3209,16 +3216,16 @@
somebody
1: HELLO
- The PCRE2_SUBSTITUTE_UNSET_EMPTY option does not affect these extended
- substitutions. However, PCRE2_SUBSTITUTE_UNKNOWN_UNSET does cause
+ The PCRE2_SUBSTITUTE_UNSET_EMPTY option does not affect these extended
+ substitutions. However, PCRE2_SUBSTITUTE_UNKNOWN_UNSET does cause
unknown groups in the extended syntax forms to be treated as unset.
- If successful, pcre2_substitute() returns the number of replacements
+ If successful, pcre2_substitute() returns the number of replacements
that were made. This may be zero if no matches were found, and is never
greater than 1 unless PCRE2_SUBSTITUTE_GLOBAL is set.
In the event of an error, a negative error code is returned. Except for
- PCRE2_ERROR_NOMATCH (which is never returned), errors from
+ PCRE2_ERROR_NOMATCH (which is never returned), errors from
pcre2_match() are passed straight back.
PCRE2_ERROR_NOSUBSTRING is returned for a non-existent substring inser-
@@ -3225,26 +3232,26 @@
tion, unless PCRE2_SUBSTITUTE_UNKNOWN_UNSET is set.
PCRE2_ERROR_UNSET is returned for an unset substring insertion (includ-
- ing an unknown substring when PCRE2_SUBSTITUTE_UNKNOWN_UNSET is set)
+ ing an unknown substring when PCRE2_SUBSTITUTE_UNKNOWN_UNSET is set)
when the simple (non-extended) syntax is used and PCRE2_SUBSTI-
TUTE_UNSET_EMPTY is not set.
- PCRE2_ERROR_NOMEMORY is returned if the output buffer is not big
+ PCRE2_ERROR_NOMEMORY is returned if the output buffer is not big
enough. If the PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option is set, the size
- of buffer that is needed is returned via outlengthptr. Note that this
+ of buffer that is needed is returned via outlengthptr. Note that this
does not happen by default.
- PCRE2_ERROR_BADREPLACEMENT is used for miscellaneous syntax errors in
+ PCRE2_ERROR_BADREPLACEMENT is used for miscellaneous syntax errors in
the replacement string, with more particular errors being
- PCRE2_ERROR_BADREPESCAPE (invalid escape sequence), PCRE2_ERROR_REP-
- MISSINGBRACE (closing curly bracket not found), PCRE2_ERROR_BADSUBSTI-
+ PCRE2_ERROR_BADREPESCAPE (invalid escape sequence), PCRE2_ERROR_REP-
+ MISSINGBRACE (closing curly bracket not found), PCRE2_ERROR_BADSUBSTI-
TUTION (syntax error in extended group substitution), and
- PCRE2_ERROR_BADSUBSPATTERN (the pattern match ended before it started
- or the match started earlier than the current position in the subject,
+ PCRE2_ERROR_BADSUBSPATTERN (the pattern match ended before it started
+ or the match started earlier than the current position in the subject,
which can happen if \K is used in an assertion).
As for all PCRE2 errors, a text message that describes the error can be
- obtained by calling the pcre2_get_error_message() function (see
+ obtained by calling the pcre2_get_error_message() function (see
"Obtaining a textual error message" above).
@@ -3253,56 +3260,56 @@
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.
@@ -3314,26 +3321,26 @@
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
+ 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 (not counting lookaround assertions), and does
- not backtrack. This has different characteristics to the normal algo-
- rithm, and is not compatible with Perl. Some of the features of PCRE2
- patterns are not supported. Nevertheless, there are times when this
- kind of matching can be useful. For a discussion of the two matching
+ not backtrack. This has different characteristics to the normal algo-
+ rithm, and is not compatible with Perl. Some of the features of PCRE2
+ patterns are not supported. Nevertheless, there are times when this
+ kind of matching can be useful. For a discussion of the two matching
algorithms, and a list of features that pcre2_dfa_match() does not sup-
port, see the pcre2matching documentation.
- 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():
@@ -3353,45 +3360,45 @@
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_ENDAN-
- CHORED, PCRE2_NOTBOL, PCRE2_NOTEOL, PCRE2_NOTEMPTY,
+ 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_ENDAN-
+ CHORED, 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
+ 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 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.
@@ -3399,8 +3406,8 @@
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
<.*>
@@ -3415,73 +3422,73 @@
<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.
- 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 such 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 such 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 backreference.
PCRE2_ERROR_DFA_UCOND
- This return is given if pcre2_dfa_match() encounters a condition item
+ This return is given if pcre2_dfa_match() encounters a condition item
that uses a backreference 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), pcre2unicode(3).
@@ -9572,7 +9579,15 @@
library cannot be reloaded on a 64-bit system, nor can they be reloaded
using the 8-bit library.
+ Note that "serialization" in PCRE2 does not convert compiled patterns
+ to an abstract format like Java or .NET serialization. The serialized
+ output is really just a bytecode dump, which is why it can only be
+ reloaded in the same environment as the one that created it. Hence the
+ restrictions mentioned above. Applications that are not statically
+ linked with a fixed version of PCRE2 must be prepared to recompile pat-
+ terns from their sources, in order to be immune to PCRE2 upgrades.
+
SECURITY CONCERNS
The facility for saving and restoring compiled patterns is intended for
@@ -9587,21 +9602,22 @@
SAVING COMPILED PATTERNS
- Before compiled patterns can be saved they must be serialized, that is,
- converted to a stream of bytes. A single byte stream may contain any
- number of compiled patterns, but they must all use the same character
- tables. A single copy of the tables is included in the byte stream (its
- size is 1088 bytes). For more details of character tables, see the sec-
- tion on locale support in the pcre2api documentation.
+ Before compiled patterns can be saved they must be serialized, which in
+ PCRE2 means converting the pattern to a stream of bytes. A single byte
+ stream may contain any number of compiled patterns, but they must all
+ use the same character tables. A single copy of the tables is included
+ in the byte stream (its size is 1088 bytes). For more details of char-
+ acter tables, see the section on locale support in the pcre2api docu-
+ mentation.
- The function pcre2_serialize_encode() creates a serialized byte stream
- from a list of compiled patterns. Its first two arguments specify the
+ The function pcre2_serialize_encode() creates a serialized byte stream
+ from a list of compiled patterns. Its first two arguments specify the
list, being a pointer to a vector of pointers to compiled patterns, and
the length of the vector. The third and fourth arguments point to vari-
ables which are set to point to the created byte stream and its length,
- respectively. The final argument is a pointer to a general context,
- which can be used to specify custom memory mangagement functions. If
- this argument is NULL, malloc() is used to obtain memory for the byte
+ respectively. The final argument is a pointer to a general context,
+ which can be used to specify custom memory mangagement functions. If
+ this argument is NULL, malloc() is used to obtain memory for the byte
stream. The yield of the function is the number of serialized patterns,
or one of the following negative error codes:
@@ -9611,12 +9627,12 @@
PCRE2_ERROR_MIXEDTABLES the patterns do not all use the same tables
PCRE2_ERROR_NULL the 1st, 3rd, or 4th argument is NULL
- PCRE2_ERROR_BADMAGIC means either that a pattern's code has been cor-
- rupted, or that a slot in the vector does not point to a compiled pat-
+ PCRE2_ERROR_BADMAGIC means either that a pattern's code has been cor-
+ rupted, or that a slot in the vector does not point to a compiled pat-
tern.
Once a set of patterns has been serialized you can save the data in any
- appropriate manner. Here is sample code that compiles two patterns and
+ appropriate manner. Here is sample code that compiles two patterns and
writes them to a file. It assumes that the variable fd refers to a file
that is open for output. The error checking that should be present in a
real application has been omitted for simplicity.
@@ -9634,13 +9650,13 @@
&bytescount, NULL);
errorcode = fwrite(bytes, 1, bytescount, fd);
- Note that the serialized data is binary data that may contain any of
- the 256 possible byte values. On systems that make a distinction
+ Note that the serialized data is binary data that may contain any of
+ the 256 possible byte values. On systems that make a distinction
between binary and non-binary data, be sure that the file is opened for
binary output.
- Serializing a set of patterns leaves the original data untouched, so
- they can still be used for matching. Their memory must eventually be
+ Serializing a set of patterns leaves the original data untouched, so
+ they can still be used for matching. Their memory must eventually be
freed in the usual way by calling pcre2_code_free(). When you have fin-
ished with the byte stream, it too must be freed by calling pcre2_seri-
alize_free().
@@ -9648,11 +9664,11 @@
RE-USING PRECOMPILED PATTERNS
- In order to re-use a set of saved patterns you must first make the
- serialized byte stream available in main memory (for example, by read-
- ing from a file). The management of this memory block is up to the
+ In order to re-use a set of saved patterns you must first make the
+ serialized byte stream available in main memory (for example, by read-
+ ing from a file). The management of this memory block is up to the
application. You can use the pcre2_serialize_get_number_of_codes()
- function to find out how many compiled patterns are in the serialized
+ function to find out how many compiled patterns are in the serialized
data without actually decoding the patterns:
uint8_t *bytes = <serialized data>;
@@ -9660,10 +9676,10 @@
The pcre2_serialize_decode() function reads a byte stream and recreates
the compiled patterns in new memory blocks, setting pointers to them in
- a vector. The first two arguments are a pointer to a suitable vector
- and its length, and the third argument points to a byte stream. The
- final argument is a pointer to a general context, which can be used to
- specify custom memory mangagement functions for the decoded patterns.
+ a vector. The first two arguments are a pointer to a suitable vector
+ and its length, and the third argument points to a byte stream. The
+ final argument is a pointer to a general context, which can be used to
+ specify custom memory mangagement functions for the decoded patterns.
If this argument is NULL, malloc() and free() are used. After deserial-
ization, the byte stream is no longer needed and can be discarded.
@@ -9673,9 +9689,9 @@
int32_t number_of_codes =
pcre2_serialize_decode(list_of_codes, 2, bytes, NULL);
- If the vector is not large enough for all the patterns in the byte
- stream, it is filled with those that fit, and the remainder are
- ignored. The yield of the function is the number of decoded patterns,
+ If the vector is not large enough for all the patterns in the byte
+ stream, it is filled with those that fit, and the remainder are
+ ignored. The yield of the function is the number of decoded patterns,
or one of the following negative error codes:
PCRE2_ERROR_BADDATA second argument is zero or less
@@ -9685,24 +9701,24 @@
PCRE2_ERROR_MEMORY memory allocation failed
PCRE2_ERROR_NULL first or third argument is NULL
- PCRE2_ERROR_BADMAGIC may mean that the data is corrupt, or that it was
+ PCRE2_ERROR_BADMAGIC may mean that the data is corrupt, or that it was
compiled on a system with different endianness.
Decoded patterns can be used for matching in the usual way, and must be
- freed by calling pcre2_code_free(). However, be aware that there is a
- potential race issue if you are using multiple patterns that were
- decoded from a single byte stream in a multithreaded application. A
+ freed by calling pcre2_code_free(). However, be aware that there is a
+ potential race issue if you are using multiple patterns that were
+ decoded from a single byte stream in a multithreaded application. A
single copy of the character tables is used by all the decoded patterns
and a reference count is used to arrange for its memory to be automati-
- cally freed when the last pattern is freed, but there is no locking on
- this reference count. Therefore, if you want to call pcre2_code_free()
- for these patterns in different threads, you must arrange your own
- locking, and ensure that pcre2_code_free() cannot be called by two
+ cally freed when the last pattern is freed, but there is no locking on
+ this reference count. Therefore, if you want to call pcre2_code_free()
+ for these patterns in different threads, you must arrange your own
+ locking, and ensure that pcre2_code_free() cannot be called by two
threads at the same time.
- If a pattern was processed by pcre2_jit_compile() before being serial-
- ized, the JIT data is discarded and so is no longer available after a
- save/restore cycle. You can, however, process a restored pattern with
+ If a pattern was processed by pcre2_jit_compile() before being serial-
+ ized, the JIT data is discarded and so is no longer available after a
+ save/restore cycle. You can, however, process a restored pattern with
pcre2_jit_compile() if you wish.
@@ -9715,8 +9731,8 @@
REVISION
- Last updated: 21 March 2017
- Copyright (c) 1997-2017 University of Cambridge.
+ Last updated: 27 June 2018
+ Copyright (c) 1997-2018 University of Cambridge.
------------------------------------------------------------------------------
Modified: code/trunk/doc/pcre2_serialize_decode.3
===================================================================
--- code/trunk/doc/pcre2_serialize_decode.3 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/pcre2_serialize_decode.3 2018-06-27 17:20:58 UTC (rev 950)
@@ -1,4 +1,4 @@
-.TH PCRE2_SERIALIZE_DECODE 3 "02 September 2015" "PCRE2 10.21"
+.TH PCRE2_SERIALIZE_DECODE 3 "27 June 2018" "PCRE2 10.32"
.SH NAME
PCRE2 - Perl-compatible regular expressions (revised API)
.SH SYNOPSIS
@@ -16,7 +16,10 @@
.rs
.sp
This function decodes a serialized set of compiled patterns back into a list of
-individual patterns. Its arguments are:
+individual patterns. This is possible only on a host that is running the same
+version of PCRE2, with the same code unit width, and the host must also have
+the same endianness, pointer width and PCRE2_SIZE type. The arguments for
+\fBpcre2_serialize_decode()\fP are:
.sp
\fIcodes\fP pointer to a vector in which to build the list
\fInumber_of_codes\fP number of slots in the vector
@@ -43,8 +46,8 @@
.\" HREF
\fBpcre2api\fP
.\"
-page and a description of the POSIX API in the
+page and a description of the serialization functions in the
.\" HREF
-\fBpcre2posix\fP
-.\"
+\fBpcre2serialize\fP
+.\"
page.
Modified: code/trunk/doc/pcre2_serialize_encode.3
===================================================================
--- code/trunk/doc/pcre2_serialize_encode.3 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/pcre2_serialize_encode.3 2018-06-27 17:20:58 UTC (rev 950)
@@ -1,4 +1,4 @@
-.TH PCRE2_SERIALIZE_ENCODE 3 "02 September 2015" "PCRE2 10.21"
+.TH PCRE2_SERIALIZE_ENCODE 3 "27 June 2018" "PCRE2 10.32"
.SH NAME
PCRE2 - Perl-compatible regular expressions (revised API)
.SH SYNOPSIS
@@ -16,7 +16,12 @@
.rs
.sp
This function encodes a list of compiled patterns into a byte stream that can
-be saved on disc or elsewhere. Its arguments are:
+be saved on disc or elsewhere. Note that this is not an abstract format like
+Java or .NET. Conversion of the byte stream back into usable compiled patterns
+can only happen on a host that is running the same version of PCRE2, with the
+same code unit width, and the host must also have the same endianness, pointer
+width and PCRE2_SIZE type. The arguments for \fBpcre2_serialize_encode()\fP
+are:
.sp
\fIcodes\fP pointer to a vector containing the list
\fInumber_of_codes\fP number of slots in the vector
@@ -42,8 +47,8 @@
.\" HREF
\fBpcre2api\fP
.\"
-page and a description of the POSIX API in the
+page and a description of the serialization functions in the
.\" HREF
-\fBpcre2posix\fP
-.\"
+\fBpcre2serialize\fP
+.\"
page.
Modified: code/trunk/doc/pcre2_serialize_free.3
===================================================================
--- code/trunk/doc/pcre2_serialize_free.3 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/pcre2_serialize_free.3 2018-06-27 17:20:58 UTC (rev 950)
@@ -1,4 +1,4 @@
-.TH PCRE2_SERIALIZE_FREE 3 "19 January 2015" "PCRE2 10.10"
+.TH PCRE2_SERIALIZE_FREE 3 "27 June 2018" "PCRE2 10.32"
.SH NAME
PCRE2 - Perl-compatible regular expressions (revised API)
.SH SYNOPSIS
@@ -21,8 +21,8 @@
.\" HREF
\fBpcre2api\fP
.\"
-page and a description of the POSIX API in the
+page and a description of the serialization functions in the
.\" HREF
-\fBpcre2posix\fP
-.\"
+\fBpcre2serialize\fP
+.\"
page.
Modified: code/trunk/doc/pcre2_serialize_get_number_of_codes.3
===================================================================
--- code/trunk/doc/pcre2_serialize_get_number_of_codes.3 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/pcre2_serialize_get_number_of_codes.3 2018-06-27 17:20:58 UTC (rev 950)
@@ -1,4 +1,4 @@
-.TH PCRE2_SERIALIZE_GET_NUMBER_OF_CODES 3 "19 January 2015" "PCRE2 10.10"
+.TH PCRE2_SERIALIZE_GET_NUMBER_OF_CODES 3 "27 June 2018" "PCRE2 10.32"
.SH NAME
PCRE2 - Perl-compatible regular expressions (revised API)
.SH SYNOPSIS
@@ -30,8 +30,8 @@
.\" HREF
\fBpcre2api\fP
.\"
-page and a description of the POSIX API in the
+page and a description of the serialization functions in the
.\" HREF
-\fBpcre2posix\fP
-.\"
+\fBpcre2serialize\fP
+.\"
page.
Modified: code/trunk/doc/pcre2api.3
===================================================================
--- code/trunk/doc/pcre2api.3 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/pcre2api.3 2018-06-27 17:20:58 UTC (rev 950)
@@ -2250,13 +2250,18 @@
.rs
.sp
It is possible to save compiled patterns on disc or elsewhere, and reload them
-later, subject to a number of restrictions. The functions whose names begin
-with \fBpcre2_serialize_\fP are used for this purpose. They are described in
-the
+later, subject to a number of restrictions. The host on which the patterns are
+reloaded must be running the same version of PCRE2, with the same code unit
+width, and must also have the same endianness, pointer width, and PCRE2_SIZE
+type. Before compiled patterns can be saved, they must be converted to a
+"serialized" form, which in the case of PCRE2 is really just a bytecode dump.
+The functions whose names begin with \fBpcre2_serialize_\fP are used for
+converting to and from the serialized form. They are described in the
.\" HREF
\fBpcre2serialize\fP
.\"
-documentation.
+documentation. Note that PCRE2 serialization does not convert compiled patterns
+to an abstract format like Java or .NET serialization.
.
.
.\" HTML <a name="matchdatablock"></a>
Modified: code/trunk/doc/pcre2serialize.3
===================================================================
--- code/trunk/doc/pcre2serialize.3 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/pcre2serialize.3 2018-06-27 17:20:58 UTC (rev 950)
@@ -1,4 +1,4 @@
-.TH PCRE2SERIALIZE 3 "21 March 2017" "PCRE2 10.30"
+.TH PCRE2SERIALIZE 3 "27 June 2018" "PCRE2 10.32"
.SH NAME
PCRE2 - Perl-compatible regular expressions (revised API)
.SH "SAVING AND RE-USING PRECOMPILED PCRE2 PATTERNS"
@@ -28,6 +28,14 @@
and PCRE2_SIZE type. For example, patterns compiled on a 32-bit system using
PCRE2's 16-bit library cannot be reloaded on a 64-bit system, nor can they be
reloaded using the 8-bit library.
+.P
+Note that "serialization" in PCRE2 does not convert compiled patterns to an
+abstract format like Java or .NET serialization. The serialized output is
+really just a bytecode dump, which is why it can only be reloaded in the same
+environment as the one that created it. Hence the restrictions mentioned above.
+Applications that are not statically linked with a fixed version of PCRE2 must
+be prepared to recompile patterns from their sources, in order to be immune to
+PCRE2 upgrades.
.
.
.SH "SECURITY CONCERNS"
@@ -46,11 +54,11 @@
.SH "SAVING COMPILED PATTERNS"
.rs
.sp
-Before compiled patterns can be saved they must be serialized, that is,
-converted to a stream of bytes. A single byte stream may contain any number of
-compiled patterns, but they must all use the same character tables. A single
-copy of the tables is included in the byte stream (its size is 1088 bytes). For
-more details of character tables, see the
+Before compiled patterns can be saved they must be serialized, which in PCRE2
+means converting the pattern to a stream of bytes. A single byte stream may
+contain any number of compiled patterns, but they must all use the same
+character tables. A single copy of the tables is included in the byte stream
+(its size is 1088 bytes). For more details of character tables, see the
.\" HTML <a href="pcre2api.html#localesupport">
.\" </a>
section on locale support
@@ -184,6 +192,6 @@
.rs
.sp
.nf
-Last updated: 21 March 2017
-Copyright (c) 1997-2017 University of Cambridge.
+Last updated: 27 June 2018
+Copyright (c) 1997-2018 University of Cambridge.
.fi
Modified: code/trunk/doc/pcre2test.1
===================================================================
--- code/trunk/doc/pcre2test.1 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/pcre2test.1 2018-06-27 17:20:58 UTC (rev 950)
@@ -1,4 +1,4 @@
-.TH PCRE2TEST 1 "25 April 2018" "PCRE 10.32"
+.TH PCRE2TEST 1 "27 June 2018" "PCRE 10.32"
.SH NAME
pcre2test - a program for testing Perl-compatible regular expressions.
.SH SYNOPSIS
@@ -1895,16 +1895,21 @@
documentation. In this section we describe the features of \fBpcre2test\fP that
can be used to test these functions.
.P
-When a pattern with \fBpush\fP modifier is successfully compiled, it is pushed
-onto a stack of compiled patterns, and \fBpcre2test\fP expects the next line to
-contain a new pattern (or command) instead of a subject line. By contrast,
-the \fBpushcopy\fP modifier causes a copy of the compiled pattern to be
-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
-patterns. The \fBjitverify\fP modifier applies only at compile time.
+Note that "serialization" in PCRE2 does not convert compiled patterns to an
+abstract format like Java or .NET. It just makes a reloadable byte code stream.
+Hence the restrictions on reloading mentioned above.
.P
+In \fBpcre2test\fP, when a pattern with \fBpush\fP modifier is successfully
+compiled, it is pushed onto a stack of compiled patterns, and \fBpcre2test\fP
+expects the next line to contain a new pattern (or command) instead of a
+subject line. By contrast, the \fBpushcopy\fP modifier causes a copy of the
+compiled pattern to be 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 patterns. The \fBjitverify\fP modifier applies only at compile
+time.
+.P
The command
.sp
#save <filename>
@@ -1975,6 +1980,6 @@
.rs
.sp
.nf
-Last updated: 25 April 2018
+Last updated: 27 June 2018
Copyright (c) 1997-2018 University of Cambridge.
.fi
Modified: code/trunk/doc/pcre2test.txt
===================================================================
--- code/trunk/doc/pcre2test.txt 2018-06-27 16:34:06 UTC (rev 949)
+++ code/trunk/doc/pcre2test.txt 2018-06-27 17:20:58 UTC (rev 950)
@@ -1747,17 +1747,21 @@
ize documentation. In this section we describe the features of
pcre2test that can be used to test these functions.
- When a pattern with push modifier is successfully compiled, it is
- pushed onto a stack of compiled patterns, and pcre2test expects the
- next line to contain a new pattern (or command) instead of a subject
- line. By contrast, the pushcopy modifier causes a copy of the compiled
- pattern to be stacked, leaving the original available for immediate
- matching. By using push and/or pushcopy, a number of patterns can be
- compiled and retained. These modifiers are incompatible with posix, and
- control modifiers that act at match time are ignored (with a message)
- for the stacked patterns. The jitverify modifier applies only at com-
- pile time.
+ Note that "serialization" in PCRE2 does not convert compiled patterns
+ to an abstract format like Java or .NET. It just makes a reloadable
+ byte code stream. Hence the restrictions on reloading mentioned above.
+ In pcre2test, when a pattern with push modifier is successfully com-
+ piled, it is pushed onto a stack of compiled patterns, and pcre2test
+ expects the next line to contain a new pattern (or command) instead of
+ a subject line. By contrast, the pushcopy modifier causes a copy of the
+ compiled pattern to be stacked, leaving the original available for
+ immediate matching. By using push and/or pushcopy, a number of patterns
+ can be compiled and retained. These modifiers are incompatible with
+ posix, and control modifiers that act at match time are ignored (with a
+ message) for the stacked patterns. The jitverify modifier applies only
+ at compile time.
+
The command
#save <filename>
@@ -1813,5 +1817,5 @@
REVISION
- Last updated: 25 April 2018
+ Last updated: 27 June 2018
Copyright (c) 1997-2018 University of Cambridge.
