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Update POSIX wrapper to use macros in the .h file, but also have the POSIX 

function names in the library.
This commit is contained in:
Philip.Hazel 2019-01-30 16:11:16 +00:00
parent 51fb3956ee
commit ae913fbee7
8 changed files with 332 additions and 320 deletions
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9
ChangeLog
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@ -14,9 +14,12 @@ a greater than 1 fixed quantifier. This issue was found by Yunho Kim.
3. Added support for callouts from pcre2_substitute().
4. The POSIX functions are now all called pcre2_regcomp() etc., with wrappers
that use the standard POSIX names. This should help avoid linking with the
wrong library in some environments.
4. The POSIX functions are now all called pcre2_regcomp() etc., with wrapper
functions that use the standard POSIX names. However, in pcre2posix.h the POSIX
names are defined as macros. This should help avoid linking with the wrong
library in some environments while still exporting the POSIX names for
pre-existing programs that use them. (The Debian alternative names are also
defined as macros, but not documented.)
5. Fix an xclass matching issue in JIT.

17
README
View File

@ -53,19 +53,8 @@ The header file for the POSIX-style functions is called pcre2posix.h. The
official POSIX name is regex.h, but I did not want to risk possible problems
with existing files of that name by distributing it that way. To use PCRE2 with
an existing program that uses the POSIX API, pcre2posix.h will have to be
renamed or pointed at by a link (or the program modified, of course).
If you are using the POSIX interface to PCRE2 and there is already a POSIX
regex library installed on your system, as well as worrying about the regex.h
header file (as mentioned above), you must also take care when linking programs
to ensure that they link with PCRE2's libpcre2-posix library. Otherwise they
may pick up the POSIX functions of the same name from the other library.
To help with this issue, the libpcre2-posix library provides alternative names
for the POSIX functions. These are the POSIX names, prefixed with "pcre2_", for
example, pcre2_regcomp(). If an application can be compiled to use the
alternative names (for example by the use of -Dregcomp=pcre2_regcomp etc.) it
can be sure of linking with the PCRE2 functions.
renamed or pointed at by a link (or the program modified, of course). See the
pcre2posix documentation for more details.
Documentation for PCRE2
@ -897,4 +886,4 @@ The distribution should contain the files listed below.
Philip Hazel
Email local part: ph10
Email domain: cam.ac.uk
Last updated: 15 November 2018
Last updated: 29 January 2019

17
doc/html/README.txt
View File

@ -53,19 +53,8 @@ The header file for the POSIX-style functions is called pcre2posix.h. The
official POSIX name is regex.h, but I did not want to risk possible problems
with existing files of that name by distributing it that way. To use PCRE2 with
an existing program that uses the POSIX API, pcre2posix.h will have to be
renamed or pointed at by a link (or the program modified, of course).
If you are using the POSIX interface to PCRE2 and there is already a POSIX
regex library installed on your system, as well as worrying about the regex.h
header file (as mentioned above), you must also take care when linking programs
to ensure that they link with PCRE2's libpcre2-posix library. Otherwise they
may pick up the POSIX functions of the same name from the other library.
To help with this issue, the libpcre2-posix library provides alternative names
for the POSIX functions. These are the POSIX names, prefixed with "pcre2_", for
example, pcre2_regcomp(). If an application can be compiled to use the
alternative names (for example by the use of -Dregcomp=pcre2_regcomp etc.) it
can be sure of linking with the PCRE2 functions.
renamed or pointed at by a link (or the program modified, of course). See the
pcre2posix documentation for more details.
Documentation for PCRE2
@ -897,4 +886,4 @@ The distribution should contain the files listed below.
Philip Hazel
Email local part: ph10
Email domain: cam.ac.uk
Last updated: 15 November 2018
Last updated: 29 January 2019

163
doc/html/pcre2posix.html
View File

@ -15,74 +15,75 @@ please consult the man page, in case the conversion went wrong.
<ul>
<li><a name="TOC1" href="#SEC1">SYNOPSIS</a>
<li><a name="TOC2" href="#SEC2">DESCRIPTION</a>
<li><a name="TOC3" href="#SEC3">COMPILING A PATTERN</a>
<li><a name="TOC4" href="#SEC4">MATCHING NEWLINE CHARACTERS</a>
<li><a name="TOC5" href="#SEC5">MATCHING A PATTERN</a>
<li><a name="TOC6" href="#SEC6">ERROR MESSAGES</a>
<li><a name="TOC7" href="#SEC7">MEMORY USAGE</a>
<li><a name="TOC8" href="#SEC8">AUTHOR</a>
<li><a name="TOC9" href="#SEC9">REVISION</a>
<li><a name="TOC3" href="#SEC3">USING THE POSIX FUNCTIONS</a>
<li><a name="TOC4" href="#SEC4">COMPILING A PATTERN</a>
<li><a name="TOC5" href="#SEC5">MATCHING NEWLINE CHARACTERS</a>
<li><a name="TOC6" href="#SEC6">MATCHING A PATTERN</a>
<li><a name="TOC7" href="#SEC7">ERROR MESSAGES</a>
<li><a name="TOC8" href="#SEC8">MEMORY USAGE</a>
<li><a name="TOC9" href="#SEC9">AUTHOR</a>
<li><a name="TOC10" href="#SEC10">REVISION</a>
</ul>
<br><a name="SEC1" href="#TOC1">SYNOPSIS</a><br>
<P>
<b>#include &#60;pcre2posix.h&#62;</b>
</P>
<P>
<b>int regcomp(regex_t *<i>preg</i>, const char *<i>pattern</i>,</b>
<b> int <i>cflags</i>);</b>
<br>
<br>
<b>int pcre2_regcomp(regex_t *<i>preg</i>, const char *<i>pattern</i>,</b>
<b> int <i>cflags</i>);</b>
<br>
<br>
<b>int regexec(const regex_t *<i>preg</i>, const char *<i>string</i>,</b>
<b> size_t <i>nmatch</i>, regmatch_t <i>pmatch</i>[], int <i>eflags</i>);</b>
<br>
<br>
<b>int pcre2_regexec(const regex_t *<i>preg</i>, const char *<i>string</i>,</b>
<b> size_t <i>nmatch</i>, regmatch_t <i>pmatch</i>[], int <i>eflags</i>);</b>
<br>
<br>
<b>size_t regerror(int <i>errcode</i>, const regex_t *<i>preg</i>,</b>
<b> char *<i>errbuf</i>, size_t <i>errbuf_size</i>);</b>
<br>
<br>
<b>size_t pcre2_regerror(int <i>errcode</i>, const regex_t *<i>preg</i>,</b>
<b> char *<i>errbuf</i>, size_t <i>errbuf_size</i>);</b>
<br>
<br>
<b>void regfree(regex_t *<i>preg</i>);</b>
<br>
<br>
<b>void pcre2_regfree(regex_t *<i>preg</i>);</b>
</P>
<br><a name="SEC2" href="#TOC1">DESCRIPTION</a><br>
<P>
This set of functions provides a POSIX-style API for the PCRE2 regular
expression 8-bit library. See the
expression 8-bit library. There are no POSIX-style wrappers for PCRE2's 16-bit
and 32-bit libraries. See the
<a href="pcre2api.html"><b>pcre2api</b></a>
documentation for a description of PCRE2's native API, which contains much
additional functionality. There are no POSIX-style wrappers for PCRE2's 16-bit
and 32-bit libraries.
additional functionality.
</P>
<P>
The functions described here are just wrapper functions that ultimately call
the PCRE2 native API. Their prototypes are defined in the <b>pcre2posix.h</b>
header file, and on Unix systems the library itself is called
<b>libpcre2-posix.a</b>, so can be accessed by adding <b>-lpcre2-posix</b> to the
command for linking an application that uses them. Because the POSIX functions
call the native ones, it is also necessary to add <b>-lpcre2-8</b>.
The functions described here are wrapper functions that ultimately call the
PCRE2 native API. Their prototypes are defined in the <b>pcre2posix.h</b> header
file, and they all have unique names starting with <b>pcre2_</b>. However, the
<b>pcre2posix.h</b> header also contains macro definitions that convert the
standard POSIX names such <b>regcomp()</b> into <b>pcre2_regcomp()</b> etc. This
means that a program can use the usual POSIX names without running the risk of
accidentally linking with POSIX functions from a different library.
</P>
<P>
When another POSIX regex library is also installed, there is the possibility of
linking an application with the wrong library. To help avoid this issue, the
PCRE2 POSIX library provides alternative names for the functions, all starting
with "pcre2_". If an application uses these names, possible ambiguity is
avoided. In the following description, however, the standard POSIX function
names are used.
On Unix-like systems the PCRE2 POSIX library is called <b>libpcre2-posix</b>, so
can be accessed by adding <b>-lpcre2-posix</b> to the command for linking an
application. Because the POSIX functions call the native ones, it is also
necessary to add <b>-lpcre2-8</b>.
</P>
<P>
Although they are not defined as protypes in <b>pcre2posix.h</b>, the library
does contain functions with the POSIX names <b>regcomp()</b> etc. These simply
pass their arguments to the PCRE2 functions. These functions are provided for
backwards compatibility with earlier versions of PCRE2, so that existing
programs do not have to be recompiled.
</P>
<P>
Calling the header file <b>pcre2posix.h</b> avoids any conflict with other POSIX
libraries. It can, of course, be renamed or aliased as <b>regex.h</b>, which is
the "correct" name, if there is no clash. It provides two structure types,
<i>regex_t</i> for compiled internal forms, and <i>regmatch_t</i> for returning
captured substrings. It also defines some constants whose names start with
"REG_"; these are used for setting options and identifying error codes.
</P>
<br><a name="SEC3" href="#TOC1">USING THE POSIX FUNCTIONS</a><br>
<P>
Those POSIX option bits that can reasonably be mapped to PCRE2 native options
have been implemented. In addition, the option REG_EXTENDED is defined with the
value zero. This has no effect, but since programs that are written to the
@ -103,17 +104,13 @@ POSIX definition; it is not fully POSIX-compatible, and in multi-unit encoding
domains it is probably even less compatible.
</P>
<P>
The header for these functions is supplied as <b>pcre2posix.h</b> to avoid any
potential clash with other POSIX libraries. It can, of course, be renamed or
aliased as <b>regex.h</b>, which is the "correct" name. It provides two
structure types, <i>regex_t</i> for compiled internal forms, and
<i>regmatch_t</i> for returning captured substrings. It also defines some
constants whose names start with "REG_"; these are used for setting options and
identifying error codes.
The descriptions below use the actual names of the functions, but, as described
above, the standard POSIX names (without the <b>pcre2_</b> prefix) may also be
used.
</P>
<br><a name="SEC3" href="#TOC1">COMPILING A PATTERN</a><br>
<br><a name="SEC4" href="#TOC1">COMPILING A PATTERN</a><br>
<P>
The function <b>regcomp()</b> is called to compile a pattern into an
The function <b>pcre2_regcomp()</b> is called to compile a pattern into an
internal form. By default, the pattern is a C string terminated by a binary
zero (but see REG_PEND below). The <i>preg</i> argument is a pointer to a
<b>regex_t</b> structure that is used as a base for storing information about
@ -151,18 +148,18 @@ REG_UTF. Note that REG_NOSPEC is not part of the POSIX standard.
<pre>
REG_NOSUB
</pre>
When a pattern that is compiled with this flag is passed to <b>regexec()</b> for
matching, the <i>nmatch</i> and <i>pmatch</i> arguments are ignored, and no
captured strings are returned. Versions of the PCRE library prior to 10.22 used
to set the PCRE2_NO_AUTO_CAPTURE compile option, but this no longer happens
because it disables the use of backreferences.
When a pattern that is compiled with this flag is passed to
<b>pcre2_regexec()</b> for matching, the <i>nmatch</i> and <i>pmatch</i> arguments
are ignored, and no captured strings are returned. Versions of the PCRE library
prior to 10.22 used to set the PCRE2_NO_AUTO_CAPTURE compile option, but this
no longer happens because it disables the use of backreferences.
<pre>
REG_PEND
</pre>
If this option is set, the <b>reg_endp</b> field in the <i>preg</i> structure
(which has the type const char *) must be set to point to the character beyond
the end of the pattern before calling <b>regcomp()</b>. The pattern itself may
now contain binary zeros, which are treated as data characters. Without
the end of the pattern before calling <b>pcre2_regcomp()</b>. The pattern itself
may now contain binary zeros, which are treated as data characters. Without
REG_PEND, a binary zero terminates the pattern and the <b>re_endp</b> field is
ignored. This is a GNU extension to the POSIX standard and should be used with
caution in software intended to be portable to other systems.
@ -197,18 +194,19 @@ newlines are matched by the dot metacharacter (they are not) or by a negative
class such as [^a] (they are).
</P>
<P>
The yield of <b>regcomp()</b> is zero on success, and non-zero otherwise. The
<i>preg</i> structure is filled in on success, and one other member of the
The yield of <b>pcre2_regcomp()</b> is zero on success, and non-zero otherwise.
The <i>preg</i> structure is filled in on success, and one other member of the
structure (as well as <i>re_endp</i>) is public: <i>re_nsub</i> contains the
number of capturing subpatterns in the regular expression. Various error codes
are defined in the header file.
</P>
<P>
NOTE: If the yield of <b>regcomp()</b> is non-zero, you must not attempt to
use the contents of the <i>preg</i> structure. If, for example, you pass it to
<b>regexec()</b>, the result is undefined and your program is likely to crash.
NOTE: If the yield of <b>pcre2_regcomp()</b> is non-zero, you must not attempt
to use the contents of the <i>preg</i> structure. If, for example, you pass it
to <b>pcre2_regexec()</b>, the result is undefined and your program is likely to
crash.
</P>
<br><a name="SEC4" href="#TOC1">MATCHING NEWLINE CHARACTERS</a><br>
<br><a name="SEC5" href="#TOC1">MATCHING NEWLINE CHARACTERS</a><br>
<P>
This area is not simple, because POSIX and Perl take different views of things.
It is not possible to get PCRE2 to obey POSIX semantics, but then PCRE2 was
@ -242,16 +240,16 @@ is no way to stop newline from matching [^a].
Default POSIX newline handling can be obtained by setting PCRE2_DOTALL and
PCRE2_DOLLAR_ENDONLY when calling <b>pcre2_compile()</b> directly, but there is
no way to make PCRE2 behave exactly as for the REG_NEWLINE action. When using
the POSIX API, passing REG_NEWLINE to PCRE2's <b>regcomp()</b> function
the POSIX API, passing REG_NEWLINE to PCRE2's <b>pcre2_regcomp()</b> function
causes PCRE2_MULTILINE to be passed to <b>pcre2_compile()</b>, and REG_DOTALL
passes PCRE2_DOTALL. There is no way to pass PCRE2_DOLLAR_ENDONLY.
</P>
<br><a name="SEC5" href="#TOC1">MATCHING A PATTERN</a><br>
<br><a name="SEC6" href="#TOC1">MATCHING A PATTERN</a><br>
<P>
The function <b>regexec()</b> is called to match a compiled pattern <i>preg</i>
against a given <i>string</i>, which is by default terminated by a zero byte
(but see REG_STARTEND below), subject to the options in <i>eflags</i>. These can
be:
The function <b>pcre2_regexec()</b> is called to match a compiled pattern
<i>preg</i> against a given <i>string</i>, which is by default terminated by a
zero byte (but see REG_STARTEND below), subject to the options in <i>eflags</i>.
These can be:
<pre>
REG_NOTBOL
</pre>
@ -295,7 +293,7 @@ are mutually exclusive; the error REG_INVARG is returned.
<P>
If the pattern was compiled with the REG_NOSUB flag, no data about any matched
strings is returned. The <i>nmatch</i> and <i>pmatch</i> arguments of
<b>regexec()</b> are ignored (except possibly as input for REG_STARTEND).
<b>pcre2_regexec()</b> are ignored (except possibly as input for REG_STARTEND).
</P>
<P>
The value of <i>nmatch</i> may be zero, and the value <i>pmatch</i> may be NULL
@ -317,24 +315,25 @@ array have both structure members set to -1.
A successful match yields a zero return; various error codes are defined in the
header file, of which REG_NOMATCH is the "expected" failure code.
</P>
<br><a name="SEC6" href="#TOC1">ERROR MESSAGES</a><br>
<br><a name="SEC7" href="#TOC1">ERROR MESSAGES</a><br>
<P>
The <b>regerror()</b> function maps a non-zero errorcode from either
<b>regcomp()</b> or <b>regexec()</b> to a printable message. If <i>preg</i> is not
NULL, the error should have arisen from the use of that structure. A message
terminated by a binary zero is placed in <i>errbuf</i>. If the buffer is too
short, only the first <i>errbuf_size</i> - 1 characters of the error message are
used. The yield of the function is the size of buffer needed to hold the whole
message, including the terminating zero. This value is greater than
<i>errbuf_size</i> if the message was truncated.
The <b>pcre2_regerror()</b> function maps a non-zero errorcode from either
<b>pcre2_regcomp()</b> or <b>pcre2_regexec()</b> to a printable message. If
<i>preg</i> is not NULL, the error should have arisen from the use of that
structure. A message terminated by a binary zero is placed in <i>errbuf</i>. If
the buffer is too short, only the first <i>errbuf_size</i> - 1 characters of the
error message are used. The yield of the function is the size of buffer needed
to hold the whole message, including the terminating zero. This value is
greater than <i>errbuf_size</i> if the message was truncated.
</P>
<br><a name="SEC7" href="#TOC1">MEMORY USAGE</a><br>
<br><a name="SEC8" href="#TOC1">MEMORY USAGE</a><br>
<P>
Compiling a regular expression causes memory to be allocated and associated
with the <i>preg</i> structure. The function <b>regfree()</b> frees all such
memory, after which <i>preg</i> may no longer be used as a compiled expression.
with the <i>preg</i> structure. The function <b>pcre2_regfree()</b> frees all
such memory, after which <i>preg</i> may no longer be used as a compiled
expression.
</P>
<br><a name="SEC8" href="#TOC1">AUTHOR</a><br>
<br><a name="SEC9" href="#TOC1">AUTHOR</a><br>
<P>
Philip Hazel
<br>
@ -343,11 +342,11 @@ University Computing Service
Cambridge, England.
<br>
</P>
<br><a name="SEC9" href="#TOC1">REVISION</a><br>
<br><a name="SEC10" href="#TOC1">REVISION</a><br>
<P>
Last updated: 19 September 2018
Last updated: 30 January 2019
<br>
Copyright &copy; 1997-2018 University of Cambridge.
Copyright &copy; 1997-2019 University of Cambridge.
<br>
<p>
Return to the <a href="index.html">PCRE2 index page</a>.

161
doc/pcre2.txt
View File

@ -9587,51 +9587,56 @@ SYNOPSIS
#include <pcre2posix.h>
int regcomp(regex_t *preg, const char *pattern,
int cflags);
int pcre2_regcomp(regex_t *preg, const char *pattern,
int cflags);
int regexec(const regex_t *preg, const char *string,
size_t nmatch, regmatch_t pmatch[], int eflags);
int pcre2_regexec(const regex_t *preg, const char *string,
size_t nmatch, regmatch_t pmatch[], int eflags);
size_t regerror(int errcode, const regex_t *preg,
char *errbuf, size_t errbuf_size);
size_t pcre2_regerror(int errcode, const regex_t *preg,
char *errbuf, size_t errbuf_size);
void regfree(regex_t *preg);
void pcre2_regfree(regex_t *preg);
DESCRIPTION
This set of functions provides a POSIX-style API for the PCRE2 regular
expression 8-bit library. See the pcre2api documentation for a descrip-
tion of PCRE2's native API, which contains much additional functional-
ity. There are no POSIX-style wrappers for PCRE2's 16-bit and 32-bit
libraries.
expression 8-bit library. There are no POSIX-style wrappers for PCRE2's
16-bit and 32-bit libraries. See the pcre2api documentation for a
description of PCRE2's native API, which contains much additional func-
tionality.
The functions described here are just wrapper functions that ultimately
call the PCRE2 native API. Their prototypes are defined in the
pcre2posix.h header file, and on Unix systems the library itself is
called libpcre2-posix.a, so can be accessed by adding -lpcre2-posix to
the command for linking an application that uses them. Because the
POSIX functions call the native ones, it is also necessary to add
-lpcre2-8.
The functions described here are wrapper functions that ultimately call
the PCRE2 native API. Their prototypes are defined in the pcre2posix.h
header file, and they all have unique names starting with pcre2_. How-
ever, the pcre2posix.h header also contains macro definitions that con-
vert the standard POSIX names such regcomp() into pcre2_regcomp() etc.
This means that a program can use the usual POSIX names without running
the risk of accidentally linking with POSIX functions from a different
library.
When another POSIX regex library is also installed, there is the possi-
bility of linking an application with the wrong library. To help avoid
this issue, the PCRE2 POSIX library provides alternative names for the
functions, all starting with "pcre2_". If an application uses these
names, possible ambiguity is avoided. In the following description,
however, the standard POSIX function names are used.
On Unix-like systems the PCRE2 POSIX library is called libpcre2-posix,
so can be accessed by adding -lpcre2-posix to the command for linking
an application. Because the POSIX functions call the native ones, it is
also necessary to add -lpcre2-8.
Although they are not defined as protypes in pcre2posix.h, the library
does contain functions with the POSIX names regcomp() etc. These simply
pass their arguments to the PCRE2 functions. These functions are pro-
vided for backwards compatibility with earlier versions of PCRE2, so
that existing programs do not have to be recompiled.
Calling the header file pcre2posix.h avoids any conflict with other
POSIX libraries. It can, of course, be renamed or aliased as regex.h,
which is the "correct" name, if there is no clash. It provides two
structure types, regex_t for compiled internal forms, and regmatch_t
for returning captured substrings. It also defines some constants whose
names start with "REG_"; these are used for setting options and identi-
fying error codes.
USING THE POSIX FUNCTIONS
Those POSIX option bits that can reasonably be mapped to PCRE2 native
options have been implemented. In addition, the option REG_EXTENDED is
@ -9653,23 +9658,19 @@ DESCRIPTION
POSIX-compatible, and in multi-unit encoding domains it is probably
even less compatible.
The header for these functions is supplied as pcre2posix.h to avoid any
potential clash with other POSIX libraries. It can, of course, be
renamed or aliased as regex.h, which is the "correct" name. It provides
two structure types, regex_t for compiled internal forms, and reg-
match_t for returning captured substrings. It also defines some con-
stants whose names start with "REG_"; these are used for setting
options and identifying error codes.
The descriptions below use the actual names of the functions, but, as
described above, the standard POSIX names (without the pcre2_ prefix)
may also be used.
COMPILING A PATTERN
The function regcomp() is called to compile a pattern into an internal
form. By default, the pattern is a C string terminated by a binary zero
(but see REG_PEND below). The preg argument is a pointer to a regex_t
structure that is used as a base for storing information about the com-
piled regular expression. (It is also used for input when REG_PEND is
set.)
The function pcre2_regcomp() is called to compile a pattern into an
internal form. By default, the pattern is a C string terminated by a
binary zero (but see REG_PEND below). The preg argument is a pointer to
a regex_t structure that is used as a base for storing information
about the compiled regular expression. (It is also used for input when
REG_PEND is set.)
The argument cflags is either zero, or contains one or more of the bits
defined by the following macros:
@ -9703,21 +9704,23 @@ COMPILING A PATTERN
REG_NOSUB
When a pattern that is compiled with this flag is passed to regexec()
for matching, the nmatch and pmatch arguments are ignored, and no cap-
tured strings are returned. Versions of the PCRE library prior to 10.22
used to set the PCRE2_NO_AUTO_CAPTURE compile option, but this no
longer happens because it disables the use of backreferences.
When a pattern that is compiled with this flag is passed to
pcre2_regexec() for matching, the nmatch and pmatch arguments are
ignored, and no captured strings are returned. Versions of the PCRE
library prior to 10.22 used to set the PCRE2_NO_AUTO_CAPTURE compile
option, but this no longer happens because it disables the use of back-
references.
REG_PEND
If this option is set, the reg_endp field in the preg structure (which
has the type const char *) must be set to point to the character beyond
the end of the pattern before calling regcomp(). The pattern itself may
now contain binary zeros, which are treated as data characters. Without
REG_PEND, a binary zero terminates the pattern and the re_endp field is
ignored. This is a GNU extension to the POSIX standard and should be
used with caution in software intended to be portable to other systems.
the end of the pattern before calling pcre2_regcomp(). The pattern
itself may now contain binary zeros, which are treated as data charac-
ters. Without REG_PEND, a binary zero terminates the pattern and the
re_endp field is ignored. This is a GNU extension to the POSIX standard
and should be used with caution in software intended to be portable to
other systems.
REG_UCP
@ -9747,15 +9750,16 @@ COMPILING A PATTERN
It does not affect the way newlines are matched by the dot metacharac-
ter (they are not) or by a negative class such as [^a] (they are).
The yield of regcomp() is zero on success, and non-zero otherwise. The
preg structure is filled in on success, and one other member of the
structure (as well as re_endp) is public: re_nsub contains the number
of capturing subpatterns in the regular expression. Various error codes
are defined in the header file.
The yield of pcre2_regcomp() is zero on success, and non-zero other-
wise. The preg structure is filled in on success, and one other member
of the structure (as well as re_endp) is public: re_nsub contains the
number of capturing subpatterns in the regular expression. Various
error codes are defined in the header file.
NOTE: If the yield of regcomp() is non-zero, you must not attempt to
use the contents of the preg structure. If, for example, you pass it to
regexec(), the result is undefined and your program is likely to crash.
NOTE: If the yield of pcre2_regcomp() is non-zero, you must not attempt
to use the contents of the preg structure. If, for example, you pass it
to pcre2_regexec(), the result is undefined and your program is likely
to crash.
MATCHING NEWLINE CHARACTERS
@ -9792,15 +9796,15 @@ MATCHING NEWLINE CHARACTERS
Default POSIX newline handling can be obtained by setting PCRE2_DOTALL
and PCRE2_DOLLAR_ENDONLY when calling pcre2_compile() directly, but
there is no way to make PCRE2 behave exactly as for the REG_NEWLINE
action. When using the POSIX API, passing REG_NEWLINE to PCRE2's reg-
comp() function causes PCRE2_MULTILINE to be passed to pcre2_compile(),
and REG_DOTALL passes PCRE2_DOTALL. There is no way to pass PCRE2_DOL-
LAR_ENDONLY.
action. When using the POSIX API, passing REG_NEWLINE to PCRE2's
pcre2_regcomp() function causes PCRE2_MULTILINE to be passed to
pcre2_compile(), and REG_DOTALL passes PCRE2_DOTALL. There is no way to
pass PCRE2_DOLLAR_ENDONLY.
MATCHING A PATTERN
The function regexec() is called to match a compiled pattern preg
The function pcre2_regexec() is called to match a compiled pattern preg
against a given string, which is by default terminated by a zero byte
(but see REG_STARTEND below), subject to the options in eflags. These
can be:
@ -9846,7 +9850,8 @@ MATCHING A PATTERN
If the pattern was compiled with the REG_NOSUB flag, no data about any
matched strings is returned. The nmatch and pmatch arguments of
regexec() are ignored (except possibly as input for REG_STARTEND).
pcre2_regexec() are ignored (except possibly as input for REG_STAR-
TEND).
The value of nmatch may be zero, and the value pmatch may be NULL
(unless REG_STARTEND is set); in both these cases no data about any
@ -9869,22 +9874,22 @@ MATCHING A PATTERN
ERROR MESSAGES
The regerror() function maps a non-zero errorcode from either regcomp()
or regexec() to a printable message. If preg is not NULL, the error
should have arisen from the use of that structure. A message terminated
by a binary zero is placed in errbuf. If the buffer is too short, only
the first errbuf_size - 1 characters of the error message are used. The
yield of the function is the size of buffer needed to hold the whole
message, including the terminating zero. This value is greater than
errbuf_size if the message was truncated.
The pcre2_regerror() function maps a non-zero errorcode from either
pcre2_regcomp() or pcre2_regexec() to a printable message. If preg is
not NULL, the error should have arisen from the use of that structure.
A message terminated by a binary zero is placed in errbuf. If the buf-
fer is too short, only the first errbuf_size - 1 characters of the
error message are used. The yield of the function is the size of buffer
needed to hold the whole message, including the terminating zero. This
value is greater than errbuf_size if the message was truncated.
MEMORY USAGE
Compiling a regular expression causes memory to be allocated and asso-
ciated with the preg structure. The function regfree() frees all such
memory, after which preg may no longer be used as a compiled expres-
sion.
ciated with the preg structure. The function pcre2_regfree() frees all
such memory, after which preg may no longer be used as a compiled
expression.
AUTHOR
@ -9896,8 +9901,8 @@ AUTHOR
REVISION
Last updated: 19 September 2018
Copyright (c) 1997-2018 University of Cambridge.
Last updated: 30 January 2019
Copyright (c) 1997-2019 University of Cambridge.
------------------------------------------------------------------------------

133
doc/pcre2posix.3
View File

@ -1,4 +1,4 @@
.TH PCRE2POSIX 3 "19 September 2018" "PCRE2 10.33"
.TH PCRE2POSIX 3 "30 January 2019" "PCRE2 10.33"
.SH NAME
PCRE2 - Perl-compatible regular expressions (revised API)
.SH "SYNOPSIS"
@ -7,26 +7,15 @@ PCRE2 - Perl-compatible regular expressions (revised API)
.B #include <pcre2posix.h>
.PP
.nf
.B int regcomp(regex_t *\fIpreg\fP, const char *\fIpattern\fP,
.B " int \fIcflags\fP);"
.sp
.B int pcre2_regcomp(regex_t *\fIpreg\fP, const char *\fIpattern\fP,
.B " int \fIcflags\fP);"
.sp
.B int regexec(const regex_t *\fIpreg\fP, const char *\fIstring\fP,
.B " size_t \fInmatch\fP, regmatch_t \fIpmatch\fP[], int \fIeflags\fP);"
.sp
.B int pcre2_regexec(const regex_t *\fIpreg\fP, const char *\fIstring\fP,
.B " size_t \fInmatch\fP, regmatch_t \fIpmatch\fP[], int \fIeflags\fP);"
.sp
.B "size_t regerror(int \fIerrcode\fP, const regex_t *\fIpreg\fP,"
.B " char *\fIerrbuf\fP, size_t \fIerrbuf_size\fP);"
.sp
.B "size_t pcre2_regerror(int \fIerrcode\fP, const regex_t *\fIpreg\fP,"
.B " char *\fIerrbuf\fP, size_t \fIerrbuf_size\fP);"
.sp
.B void regfree(regex_t *\fIpreg\fP);
.sp
.B void pcre2_regfree(regex_t *\fIpreg\fP);
.fi
.
@ -34,28 +23,44 @@ PCRE2 - Perl-compatible regular expressions (revised API)
.rs
.sp
This set of functions provides a POSIX-style API for the PCRE2 regular
expression 8-bit library. See the
expression 8-bit library. There are no POSIX-style wrappers for PCRE2's 16-bit
and 32-bit libraries. See the
.\" HREF
\fBpcre2api\fP
.\"
documentation for a description of PCRE2's native API, which contains much
additional functionality. There are no POSIX-style wrappers for PCRE2's 16-bit
and 32-bit libraries.
additional functionality.
.P
The functions described here are just wrapper functions that ultimately call
the PCRE2 native API. Their prototypes are defined in the \fBpcre2posix.h\fP
header file, and on Unix systems the library itself is called
\fBlibpcre2-posix.a\fP, so can be accessed by adding \fB-lpcre2-posix\fP to the
command for linking an application that uses them. Because the POSIX functions
call the native ones, it is also necessary to add \fB-lpcre2-8\fP.
The functions described here are wrapper functions that ultimately call the
PCRE2 native API. Their prototypes are defined in the \fBpcre2posix.h\fP header
file, and they all have unique names starting with \fBpcre2_\fP. However, the
\fBpcre2posix.h\fP header also contains macro definitions that convert the
standard POSIX names such \fBregcomp()\fP into \fBpcre2_regcomp()\fP etc. This
means that a program can use the usual POSIX names without running the risk of
accidentally linking with POSIX functions from a different library.
.P
When another POSIX regex library is also installed, there is the possibility of
linking an application with the wrong library. To help avoid this issue, the
PCRE2 POSIX library provides alternative names for the functions, all starting
with "pcre2_". If an application uses these names, possible ambiguity is
avoided. In the following description, however, the standard POSIX function
names are used.
On Unix-like systems the PCRE2 POSIX library is called \fBlibpcre2-posix\fP, so
can be accessed by adding \fB-lpcre2-posix\fP to the command for linking an
application. Because the POSIX functions call the native ones, it is also
necessary to add \fB-lpcre2-8\fP.
.P
Although they are not defined as protypes in \fBpcre2posix.h\fP, the library
does contain functions with the POSIX names \fBregcomp()\fP etc. These simply
pass their arguments to the PCRE2 functions. These functions are provided for
backwards compatibility with earlier versions of PCRE2, so that existing
programs do not have to be recompiled.
.P
Calling the header file \fBpcre2posix.h\fP avoids any conflict with other POSIX
libraries. It can, of course, be renamed or aliased as \fBregex.h\fP, which is
the "correct" name, if there is no clash. It provides two structure types,
\fIregex_t\fP for compiled internal forms, and \fIregmatch_t\fP for returning
captured substrings. It also defines some constants whose names start with
"REG_"; these are used for setting options and identifying error codes.
.
.
.SH "USING THE POSIX FUNCTIONS"
.rs
.sp
Those POSIX option bits that can reasonably be mapped to PCRE2 native options
have been implemented. In addition, the option REG_EXTENDED is defined with the
value zero. This has no effect, but since programs that are written to the
@ -73,19 +78,15 @@ described below. "POSIX-like in style" means that the API approximates to the
POSIX definition; it is not fully POSIX-compatible, and in multi-unit encoding
domains it is probably even less compatible.
.P
The header for these functions is supplied as \fBpcre2posix.h\fP to avoid any
potential clash with other POSIX libraries. It can, of course, be renamed or
aliased as \fBregex.h\fP, which is the "correct" name. It provides two
structure types, \fIregex_t\fP for compiled internal forms, and
\fIregmatch_t\fP for returning captured substrings. It also defines some
constants whose names start with "REG_"; these are used for setting options and
identifying error codes.
The descriptions below use the actual names of the functions, but, as described
above, the standard POSIX names (without the \fBpcre2_\fP prefix) may also be
used.
.
.
.SH "COMPILING A PATTERN"
.rs
.sp
The function \fBregcomp()\fP is called to compile a pattern into an
The function \fBpcre2_regcomp()\fP is called to compile a pattern into an
internal form. By default, the pattern is a C string terminated by a binary
zero (but see REG_PEND below). The \fIpreg\fP argument is a pointer to a
\fBregex_t\fP structure that is used as a base for storing information about
@ -122,18 +123,18 @@ REG_UTF. Note that REG_NOSPEC is not part of the POSIX standard.
.sp
REG_NOSUB
.sp
When a pattern that is compiled with this flag is passed to \fBregexec()\fP for
matching, the \fInmatch\fP and \fIpmatch\fP arguments are ignored, and no
captured strings are returned. Versions of the PCRE library prior to 10.22 used
to set the PCRE2_NO_AUTO_CAPTURE compile option, but this no longer happens
because it disables the use of backreferences.
When a pattern that is compiled with this flag is passed to
\fBpcre2_regexec()\fP for matching, the \fInmatch\fP and \fIpmatch\fP arguments
are ignored, and no captured strings are returned. Versions of the PCRE library
prior to 10.22 used to set the PCRE2_NO_AUTO_CAPTURE compile option, but this
no longer happens because it disables the use of backreferences.
.sp
REG_PEND
.sp
If this option is set, the \fBreg_endp\fP field in the \fIpreg\fP structure
(which has the type const char *) must be set to point to the character beyond
the end of the pattern before calling \fBregcomp()\fP. The pattern itself may
now contain binary zeros, which are treated as data characters. Without
the end of the pattern before calling \fBpcre2_regcomp()\fP. The pattern itself
may now contain binary zeros, which are treated as data characters. Without
REG_PEND, a binary zero terminates the pattern and the \fBre_endp\fP field is
ignored. This is a GNU extension to the POSIX standard and should be used with
caution in software intended to be portable to other systems.
@ -166,15 +167,16 @@ Perl way, not the POSIX way. Note that setting PCRE2_MULTILINE has only
newlines are matched by the dot metacharacter (they are not) or by a negative
class such as [^a] (they are).
.P
The yield of \fBregcomp()\fP is zero on success, and non-zero otherwise. The
\fIpreg\fP structure is filled in on success, and one other member of the
The yield of \fBpcre2_regcomp()\fP is zero on success, and non-zero otherwise.
The \fIpreg\fP structure is filled in on success, and one other member of the
structure (as well as \fIre_endp\fP) is public: \fIre_nsub\fP contains the
number of capturing subpatterns in the regular expression. Various error codes
are defined in the header file.
.P
NOTE: If the yield of \fBregcomp()\fP is non-zero, you must not attempt to
use the contents of the \fIpreg\fP structure. If, for example, you pass it to
\fBregexec()\fP, the result is undefined and your program is likely to crash.
NOTE: If the yield of \fBpcre2_regcomp()\fP is non-zero, you must not attempt
to use the contents of the \fIpreg\fP structure. If, for example, you pass it
to \fBpcre2_regexec()\fP, the result is undefined and your program is likely to
crash.
.
.
.SH "MATCHING NEWLINE CHARACTERS"
@ -211,7 +213,7 @@ is no way to stop newline from matching [^a].
Default POSIX newline handling can be obtained by setting PCRE2_DOTALL and
PCRE2_DOLLAR_ENDONLY when calling \fBpcre2_compile()\fP directly, but there is
no way to make PCRE2 behave exactly as for the REG_NEWLINE action. When using
the POSIX API, passing REG_NEWLINE to PCRE2's \fBregcomp()\fP function
the POSIX API, passing REG_NEWLINE to PCRE2's \fBpcre2_regcomp()\fP function
causes PCRE2_MULTILINE to be passed to \fBpcre2_compile()\fP, and REG_DOTALL
passes PCRE2_DOTALL. There is no way to pass PCRE2_DOLLAR_ENDONLY.
.
@ -219,10 +221,10 @@ passes PCRE2_DOTALL. There is no way to pass PCRE2_DOLLAR_ENDONLY.
.SH "MATCHING A PATTERN"
.rs
.sp
The function \fBregexec()\fP is called to match a compiled pattern \fIpreg\fP
against a given \fIstring\fP, which is by default terminated by a zero byte
(but see REG_STARTEND below), subject to the options in \fIeflags\fP. These can
be:
The function \fBpcre2_regexec()\fP is called to match a compiled pattern
\fIpreg\fP against a given \fIstring\fP, which is by default terminated by a
zero byte (but see REG_STARTEND below), subject to the options in \fIeflags\fP.
These can be:
.sp
REG_NOTBOL
.sp
@ -263,7 +265,7 @@ are mutually exclusive; the error REG_INVARG is returned.
.P
If the pattern was compiled with the REG_NOSUB flag, no data about any matched
strings is returned. The \fInmatch\fP and \fIpmatch\fP arguments of
\fBregexec()\fP are ignored (except possibly as input for REG_STARTEND).
\fBpcre2_regexec()\fP are ignored (except possibly as input for REG_STARTEND).
.P
The value of \fInmatch\fP may be zero, and the value \fIpmatch\fP may be NULL
(unless REG_STARTEND is set); in both these cases no data about any matched
@ -286,22 +288,23 @@ header file, of which REG_NOMATCH is the "expected" failure code.
.SH "ERROR MESSAGES"
.rs
.sp
The \fBregerror()\fP function maps a non-zero errorcode from either
\fBregcomp()\fP or \fBregexec()\fP to a printable message. If \fIpreg\fP is not
NULL, the error should have arisen from the use of that structure. A message
terminated by a binary zero is placed in \fIerrbuf\fP. If the buffer is too
short, only the first \fIerrbuf_size\fP - 1 characters of the error message are
used. The yield of the function is the size of buffer needed to hold the whole
message, including the terminating zero. This value is greater than
\fIerrbuf_size\fP if the message was truncated.
The \fBpcre2_regerror()\fP function maps a non-zero errorcode from either
\fBpcre2_regcomp()\fP or \fBpcre2_regexec()\fP to a printable message. If
\fIpreg\fP is not NULL, the error should have arisen from the use of that
structure. A message terminated by a binary zero is placed in \fIerrbuf\fP. If
the buffer is too short, only the first \fIerrbuf_size\fP - 1 characters of the
error message are used. The yield of the function is the size of buffer needed
to hold the whole message, including the terminating zero. This value is
greater than \fIerrbuf_size\fP if the message was truncated.
.
.
.SH MEMORY USAGE
.rs
.sp
Compiling a regular expression causes memory to be allocated and associated
with the \fIpreg\fP structure. The function \fBregfree()\fP frees all such
memory, after which \fIpreg\fP may no longer be used as a compiled expression.
with the \fIpreg\fP structure. The function \fBpcre2_regfree()\fP frees all
such memory, after which \fIpreg\fP may no longer be used as a compiled
expression.
.
.
.SH AUTHOR
@ -318,6 +321,6 @@ Cambridge, England.
.rs
.sp
.nf
Last updated: 19 September 2018
Copyright (c) 1997-2018 University of Cambridge.
Last updated: 30 January 2019
Copyright (c) 1997-2019 University of Cambridge.
.fi

25
src/pcre2posix.c
View File

@ -7,7 +7,7 @@ and semantics are as close as possible to those of the Perl 5 language.
Written by Philip Hazel
Original API code Copyright (c) 1997-2012 University of Cambridge
New API code Copyright (c) 2016-2018 University of Cambridge
New API code Copyright (c) 2016-2019 University of Cambridge
-----------------------------------------------------------------------------
Redistribution and use in source and binary forms, with or without
@ -41,9 +41,11 @@ POSSIBILITY OF SUCH DAMAGE.
/* This module is a wrapper that provides a POSIX API to the underlying PCRE2
functions. The operative functions are called pcre2_regcomp(), etc., with
wrappers that use the plain POSIX names. This makes it easier for an
application to be sure it gets the PCRE2 versions in the presence of other
POSIX regex libraries. */
wrappers that use the plain POSIX names. In addition, pcre2posix.h defines the
POSIX names as macros for the pcre2_xxx functions, so any program that includes
it and uses the POSIX names will call the base functions directly. This makes
it easier for an application to be sure it gets the PCRE2 versions in the
presence of other POSIX regex libraries. */
#ifdef HAVE_CONFIG_H
@ -177,24 +179,39 @@ static const char *const pstring[] = {
* Wrappers with traditional POSIX names *
*************************************************/
/* Keep defining them to preseve the ABI for applications linked to the pcre2
POSIX library before these names were changed into macros in pcre2posix.h.
This also ensures that the POSIX names are callable from languages that do not
include pcre2posix.h. It is vital to #undef the macro definitions from
pcre2posix.h! */
#undef regerror
PCRE2POSIX_EXP_DECL size_t regerror(int, const regex_t *, char *, size_t);
PCRE2POSIX_EXP_DEFN size_t PCRE2_CALL_CONVENTION
regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size)
{
return pcre2_regerror(errcode, preg, errbuf, errbuf_size);
}
#undef regfree
PCRE2POSIX_EXP_DECL void regfree(regex_t *);
PCRE2POSIX_EXP_DEFN void PCRE2_CALL_CONVENTION
regfree(regex_t *preg)
{
pcre2_regfree(preg);
}
#undef regcomp
PCRE2POSIX_EXP_DECL int regcomp(regex_t *, const char *, int);
PCRE2POSIX_EXP_DEFN int PCRE2_CALL_CONVENTION
regcomp(regex_t *preg, const char *pattern, int cflags)
{
return pcre2_regcomp(preg, pattern, cflags);
}
#undef regexec
PCRE2POSIX_EXP_DECL int regexec(const regex_t *, const char *, size_t,
regmatch_t *, int);
PCRE2POSIX_EXP_DEFN int PCRE2_CALL_CONVENTION
regexec(const regex_t *preg, const char *string, size_t nmatch,
regmatch_t pmatch[], int eflags)

29
src/pcre2posix.h
View File

@ -9,7 +9,7 @@ POSIX wrapper interface.
Written by Philip Hazel
Original API code Copyright (c) 1997-2012 University of Cambridge
New API code Copyright (c) 2016-2018 University of Cambridge
New API code Copyright (c) 2016-2019 University of Cambridge
-----------------------------------------------------------------------------
Redistribution and use in source and binary forms, with or without
@ -139,22 +139,29 @@ file. */
#endif
/* The functions. The actual code is in functions with pcre2_xxx names for
uniqueness. Wrappers with the POSIX names are provided for those who can ensure
they get them from the PCRE2 library and not by accident from elsewhere. */
uniqueness. POSIX names are provided as macros for API compatibility with POSIX
regex functions. It's done this way to ensure to they are always linked from
the PCRE2 library and not by accident from elsewhere (regex_t differs in size
elsewhere). */
PCRE2POSIX_EXP_DECL int pcre2_regcomp(regex_t *, const char *, int);
PCRE2POSIX_EXP_DECL int regcomp(regex_t *, const char *, int);
PCRE2POSIX_EXP_DECL int pcre2_regexec(const regex_t *, const char *, size_t,
regmatch_t *, int);
PCRE2POSIX_EXP_DECL int regexec(const regex_t *, const char *, size_t,
regmatch_t *, int);
PCRE2POSIX_EXP_DECL size_t pcre2_regerror(int, const regex_t *, char *, size_t);
PCRE2POSIX_EXP_DECL size_t regerror(int, const regex_t *, char *, size_t);
PCRE2POSIX_EXP_DECL void pcre2_regfree(regex_t *);
PCRE2POSIX_EXP_DECL void regfree(regex_t *);
#define regcomp pcre2_regcomp
#define regexec pcre2_regexec
#define regerror pcre2_regerror
#define regfree pcre2_regfree
/* Debian had a patch that used different names. These are now here to save
them having to maintain their own patch, but are not documented by PCRE2. */
#define PCRE2regcomp pcre2_regcomp
#define PCRE2regexec pcre2_regexec
#define PCRE2regerror pcre2_regerror
#define PCRE2regfree pcre2_regfree
#ifdef __cplusplus
} /* extern "C" */