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1 README file for PCRE (Perl-compatible regular expression library)
2 -----------------------------------------------------------------
4 The latest release of PCRE is always available in three alternative formats
5 from:
7 ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-xxx.tar.gz
8 ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-xxx.tar.bz2
9 ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-xxx.zip
11 There is a mailing list for discussion about the development of PCRE at
13 pcre-dev@exim.org
15 Please read the NEWS file if you are upgrading from a previous release.
16 The contents of this README file are:
18 The PCRE APIs
19 Documentation for PCRE
20 Contributions by users of PCRE
21 Building PCRE on non-Unix systems
22 Building PCRE on Unix-like systems
23 Retrieving configuration information on Unix-like systems
24 Shared libraries on Unix-like systems
25 Cross-compiling on Unix-like systems
26 Using HP's ANSI C++ compiler (aCC)
27 Using PCRE from MySQL
28 Making new tarballs
29 Testing PCRE
30 Character tables
31 File manifest
34 The PCRE APIs
35 -------------
37 PCRE is written in C, and it has its own API. The distribution also includes a
38 set of C++ wrapper functions (see the pcrecpp man page for details), courtesy
39 of Google Inc.
41 In addition, there is a set of C wrapper functions that are based on the POSIX
42 regular expression API (see the pcreposix man page). These end up in the
43 library called libpcreposix. Note that this just provides a POSIX calling
44 interface to PCRE; the regular expressions themselves still follow Perl syntax
45 and semantics. The POSIX API is restricted, and does not give full access to
46 all of PCRE's facilities.
48 The header file for the POSIX-style functions is called pcreposix.h. The
49 official POSIX name is regex.h, but I did not want to risk possible problems
50 with existing files of that name by distributing it that way. To use PCRE with
51 an existing program that uses the POSIX API, pcreposix.h will have to be
52 renamed or pointed at by a link.
54 If you are using the POSIX interface to PCRE and there is already a POSIX regex
55 library installed on your system, as well as worrying about the regex.h header
56 file (as mentioned above), you must also take care when linking programs to
57 ensure that they link with PCRE's libpcreposix library. Otherwise they may pick
58 up the POSIX functions of the same name from the other library.
60 One way of avoiding this confusion is to compile PCRE with the addition of
61 -Dregcomp=PCREregcomp (and similarly for the other POSIX functions) to the
62 compiler flags (CFLAGS if you are using "configure" -- see below). This has the
63 effect of renaming the functions so that the names no longer clash. Of course,
64 you have to do the same thing for your applications, or write them using the
65 new names.
68 Documentation for PCRE
69 ----------------------
71 If you install PCRE in the normal way on a Unix-like system, you will end up
72 with a set of man pages whose names all start with "pcre". The one that is just
73 called "pcre" lists all the others. In addition to these man pages, the PCRE
74 documentation is supplied in two other forms:
76 1. There are files called doc/pcre.txt, doc/pcregrep.txt, and
77 doc/pcretest.txt in the source distribution. The first of these is a
78 concatenation of the text forms of all the section 3 man pages except
79 those that summarize individual functions. The other two are the text
80 forms of the section 1 man pages for the pcregrep and pcretest commands.
81 These text forms are provided for ease of scanning with text editors or
82 similar tools. They are installed in <prefix>/share/doc/pcre, where
83 <prefix> is the installation prefix (defaulting to /usr/local).
85 2. A set of files containing all the documentation in HTML form, hyperlinked
86 in various ways, and rooted in a file called index.html, is distributed in
87 doc/html and installed in <prefix>/share/doc/pcre/html.
89 Users of PCRE have contributed files containing the documentation for various
90 releases in CHM format. These can be found in the Contrib directory of the FTP
91 site (see next section).
94 Contributions by users of PCRE
95 ------------------------------
97 You can find contributions from PCRE users in the directory
99 ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/Contrib
101 There is a README file giving brief descriptions of what they are. Some are
102 complete in themselves; others are pointers to URLs containing relevant files.
103 Some of this material is likely to be well out-of-date. Several of the earlier
104 contributions provided support for compiling PCRE on various flavours of
105 Windows (I myself do not use Windows). Nowadays there is more Windows support
106 in the standard distribution, so these contibutions have been archived.
109 Building PCRE on non-Unix systems
110 ---------------------------------
112 For a non-Unix system, please read the comments in the file NON-UNIX-USE,
113 though if your system supports the use of "configure" and "make" you may be
114 able to build PCRE in the same way as for Unix-like systems. PCRE can also be
115 configured in many platform environments using the GUI facility provided by
116 CMake's cmake-gui command. This creates Makefiles, solution files, etc.
118 PCRE has been compiled on many different operating systems. It should be
119 straightforward to build PCRE on any system that has a Standard C compiler and
120 library, because it uses only Standard C functions.
123 Building PCRE on Unix-like systems
124 ----------------------------------
126 If you are using HP's ANSI C++ compiler (aCC), please see the special note
127 in the section entitled "Using HP's ANSI C++ compiler (aCC)" below.
129 The following instructions assume the use of the widely used "configure, make,
130 make install" process. There is also support for CMake in the PCRE
131 distribution; there are some comments about using CMake in the NON-UNIX-USE
132 file, though it can also be used in Unix-like systems.
134 To build PCRE on a Unix-like system, first run the "configure" command from the
135 PCRE distribution directory, with your current directory set to the directory
136 where you want the files to be created. This command is a standard GNU
137 "autoconf" configuration script, for which generic instructions are supplied in
138 the file INSTALL.
140 Most commonly, people build PCRE within its own distribution directory, and in
141 this case, on many systems, just running "./configure" is sufficient. However,
142 the usual methods of changing standard defaults are available. For example:
144 CFLAGS='-O2 -Wall' ./configure --prefix=/opt/local
146 specifies that the C compiler should be run with the flags '-O2 -Wall' instead
147 of the default, and that "make install" should install PCRE under /opt/local
148 instead of the default /usr/local.
150 If you want to build in a different directory, just run "configure" with that
151 directory as current. For example, suppose you have unpacked the PCRE source
152 into /source/pcre/pcre-xxx, but you want to build it in /build/pcre/pcre-xxx:
154 cd /build/pcre/pcre-xxx
155 /source/pcre/pcre-xxx/configure
157 PCRE is written in C and is normally compiled as a C library. However, it is
158 possible to build it as a C++ library, though the provided building apparatus
159 does not have any features to support this.
161 There are some optional features that can be included or omitted from the PCRE
162 library. You can read more about them in the pcrebuild man page.
164 . If you want to suppress the building of the C++ wrapper library, you can add
165 --disable-cpp to the "configure" command. Otherwise, when "configure" is run,
166 it will try to find a C++ compiler and C++ header files, and if it succeeds,
167 it will try to build the C++ wrapper.
169 . If you want to make use of the support for UTF-8 Unicode character strings in
170 PCRE, you must add --enable-utf8 to the "configure" command. Without it, the
171 code for handling UTF-8 is not included in the library. Even when included,
172 it still has to be enabled by an option at run time. When PCRE is compiled
173 with this option, its input can only either be ASCII or UTF-8, even when
174 running on EBCDIC platforms. It is not possible to use both --enable-utf8 and
175 --enable-ebcdic at the same time.
177 . If, in addition to support for UTF-8 character strings, you want to include
178 support for the \P, \p, and \X sequences that recognize Unicode character
179 properties, you must add --enable-unicode-properties to the "configure"
180 command. This adds about 30K to the size of the library (in the form of a
181 property table); only the basic two-letter properties such as Lu are
182 supported.
184 . You can build PCRE to recognize either CR or LF or the sequence CRLF or any
185 of the preceding, or any of the Unicode newline sequences as indicating the
186 end of a line. Whatever you specify at build time is the default; the caller
187 of PCRE can change the selection at run time. The default newline indicator
188 is a single LF character (the Unix standard). You can specify the default
189 newline indicator by adding --enable-newline-is-cr or --enable-newline-is-lf
190 or --enable-newline-is-crlf or --enable-newline-is-anycrlf or
191 --enable-newline-is-any to the "configure" command, respectively.
193 If you specify --enable-newline-is-cr or --enable-newline-is-crlf, some of
194 the standard tests will fail, because the lines in the test files end with
195 LF. Even if the files are edited to change the line endings, there are likely
196 to be some failures. With --enable-newline-is-anycrlf or
197 --enable-newline-is-any, many tests should succeed, but there may be some
198 failures.
200 . By default, the sequence \R in a pattern matches any Unicode line ending
201 sequence. This is independent of the option specifying what PCRE considers to
202 be the end of a line (see above). However, the caller of PCRE can restrict \R
203 to match only CR, LF, or CRLF. You can make this the default by adding
204 --enable-bsr-anycrlf to the "configure" command (bsr = "backslash R").
206 . When called via the POSIX interface, PCRE uses malloc() to get additional
207 storage for processing capturing parentheses if there are more than 10 of
208 them in a pattern. You can increase this threshold by setting, for example,
210 --with-posix-malloc-threshold=20
212 on the "configure" command.
214 . PCRE has a counter that can be set to limit the amount of resources it uses.
215 If the limit is exceeded during a match, the match fails. The default is ten
216 million. You can change the default by setting, for example,
218 --with-match-limit=500000
220 on the "configure" command. This is just the default; individual calls to
221 pcre_exec() can supply their own value. There is more discussion on the
222 pcreapi man page.
224 . There is a separate counter that limits the depth of recursive function calls
225 during a matching process. This also has a default of ten million, which is
226 essentially "unlimited". You can change the default by setting, for example,
228 --with-match-limit-recursion=500000
230 Recursive function calls use up the runtime stack; running out of stack can
231 cause programs to crash in strange ways. There is a discussion about stack
232 sizes in the pcrestack man page.
234 . The default maximum compiled pattern size is around 64K. You can increase
235 this by adding --with-link-size=3 to the "configure" command. You can
236 increase it even more by setting --with-link-size=4, but this is unlikely
237 ever to be necessary. Increasing the internal link size will reduce
238 performance.
240 . You can build PCRE so that its internal match() function that is called from
241 pcre_exec() does not call itself recursively. Instead, it uses memory blocks
242 obtained from the heap via the special functions pcre_stack_malloc() and
243 pcre_stack_free() to save data that would otherwise be saved on the stack. To
244 build PCRE like this, use
246 --disable-stack-for-recursion
248 on the "configure" command. PCRE runs more slowly in this mode, but it may be
249 necessary in environments with limited stack sizes. This applies only to the
250 pcre_exec() function; it does not apply to pcre_dfa_exec(), which does not
251 use deeply nested recursion. There is a discussion about stack sizes in the
252 pcrestack man page.
254 . For speed, PCRE uses four tables for manipulating and identifying characters
255 whose code point values are less than 256. By default, it uses a set of
256 tables for ASCII encoding that is part of the distribution. If you specify
258 --enable-rebuild-chartables
260 a program called dftables is compiled and run in the default C locale when
261 you obey "make". It builds a source file called pcre_chartables.c. If you do
262 not specify this option, pcre_chartables.c is created as a copy of
263 pcre_chartables.c.dist. See "Character tables" below for further information.
265 . It is possible to compile PCRE for use on systems that use EBCDIC as their
266 character code (as opposed to ASCII) by specifying
268 --enable-ebcdic
270 This automatically implies --enable-rebuild-chartables (see above). However,
271 when PCRE is built this way, it always operates in EBCDIC. It cannot support
272 both EBCDIC and UTF-8.
274 . It is possible to compile pcregrep to use libz and/or libbz2, in order to
275 read .gz and .bz2 files (respectively), by specifying one or both of
277 --enable-pcregrep-libz
278 --enable-pcregrep-libbz2
280 Of course, the relevant libraries must be installed on your system.
282 . It is possible to compile pcretest so that it links with the libreadline
283 library, by specifying
285 --enable-pcretest-libreadline
287 If this is done, when pcretest's input is from a terminal, it reads it using
288 the readline() function. This provides line-editing and history facilities.
289 Note that libreadline is GPL-licenced, so if you distribute a binary of
290 pcretest linked in this way, there may be licensing issues.
292 Setting this option causes the -lreadline option to be added to the pcretest
293 build. In many operating environments with a sytem-installed readline
294 library this is sufficient. However, in some environments (e.g. if an
295 unmodified distribution version of readline is in use), it may be necessary
296 to specify something like LIBS="-lncurses" as well. This is because, to quote
297 the readline INSTALL, "Readline uses the termcap functions, but does not link
298 with the termcap or curses library itself, allowing applications which link
299 with readline the to choose an appropriate library." If you get error
300 messages about missing functions tgetstr, tgetent, tputs, tgetflag, or tgoto,
301 this is the problem, and linking with the ncurses library should fix it.
303 The "configure" script builds the following files for the basic C library:
305 . Makefile is the makefile that builds the library
306 . config.h contains build-time configuration options for the library
307 . pcre.h is the public PCRE header file
308 . pcre-config is a script that shows the settings of "configure" options
309 . libpcre.pc is data for the pkg-config command
310 . libtool is a script that builds shared and/or static libraries
311 . RunTest is a script for running tests on the basic C library
312 . RunGrepTest is a script for running tests on the pcregrep command
314 Versions of config.h and pcre.h are distributed in the PCRE tarballs under
315 the names config.h.generic and pcre.h.generic. These are provided for the
316 benefit of those who have to built PCRE without the benefit of "configure". If
317 you use "configure", the .generic versions are not used.
319 If a C++ compiler is found, the following files are also built:
321 . libpcrecpp.pc is data for the pkg-config command
322 . pcrecpparg.h is a header file for programs that call PCRE via the C++ wrapper
323 . pcre_stringpiece.h is the header for the C++ "stringpiece" functions
325 The "configure" script also creates config.status, which is an executable
326 script that can be run to recreate the configuration, and config.log, which
327 contains compiler output from tests that "configure" runs.
329 Once "configure" has run, you can run "make". It builds two libraries, called
330 libpcre and libpcreposix, a test program called pcretest, and the pcregrep
331 command. If a C++ compiler was found on your system, "make" also builds the C++
332 wrapper library, which is called libpcrecpp, and some test programs called
333 pcrecpp_unittest, pcre_scanner_unittest, and pcre_stringpiece_unittest.
334 Building the C++ wrapper can be disabled by adding --disable-cpp to the
335 "configure" command.
337 The command "make check" runs all the appropriate tests. Details of the PCRE
338 tests are given below in a separate section of this document.
340 You can use "make install" to install PCRE into live directories on your
341 system. The following are installed (file names are all relative to the
342 <prefix> that is set when "configure" is run):
344 Commands (bin):
345 pcretest
346 pcregrep
347 pcre-config
349 Libraries (lib):
350 libpcre
351 libpcreposix
352 libpcrecpp (if C++ support is enabled)
354 Configuration information (lib/pkgconfig):
355 libpcre.pc
356 libpcrecpp.pc (if C++ support is enabled)
358 Header files (include):
359 pcre.h
360 pcreposix.h
361 pcre_scanner.h )
362 pcre_stringpiece.h ) if C++ support is enabled
363 pcrecpp.h )
364 pcrecpparg.h )
366 Man pages (share/man/man{1,3}):
367 pcregrep.1
368 pcretest.1
369 pcre.3
370 pcre*.3 (lots more pages, all starting "pcre")
372 HTML documentation (share/doc/pcre/html):
373 index.html
374 *.html (lots more pages, hyperlinked from index.html)
376 Text file documentation (share/doc/pcre):
379 ChangeLog
381 NEWS
383 pcre.txt (a concatenation of the man(3) pages)
384 pcretest.txt the pcretest man page
385 pcregrep.txt the pcregrep man page
387 If you want to remove PCRE from your system, you can run "make uninstall".
388 This removes all the files that "make install" installed. However, it does not
389 remove any directories, because these are often shared with other programs.
392 Retrieving configuration information on Unix-like systems
393 ---------------------------------------------------------
395 Running "make install" installs the command pcre-config, which can be used to
396 recall information about the PCRE configuration and installation. For example:
398 pcre-config --version
400 prints the version number, and
402 pcre-config --libs
404 outputs information about where the library is installed. This command can be
405 included in makefiles for programs that use PCRE, saving the programmer from
406 having to remember too many details.
408 The pkg-config command is another system for saving and retrieving information
409 about installed libraries. Instead of separate commands for each library, a
410 single command is used. For example:
412 pkg-config --cflags pcre
414 The data is held in *.pc files that are installed in a directory called
415 <prefix>/lib/pkgconfig.
418 Shared libraries on Unix-like systems
419 -------------------------------------
421 The default distribution builds PCRE as shared libraries and static libraries,
422 as long as the operating system supports shared libraries. Shared library
423 support relies on the "libtool" script which is built as part of the
424 "configure" process.
426 The libtool script is used to compile and link both shared and static
427 libraries. They are placed in a subdirectory called .libs when they are newly
428 built. The programs pcretest and pcregrep are built to use these uninstalled
429 libraries (by means of wrapper scripts in the case of shared libraries). When
430 you use "make install" to install shared libraries, pcregrep and pcretest are
431 automatically re-built to use the newly installed shared libraries before being
432 installed themselves. However, the versions left in the build directory still
433 use the uninstalled libraries.
435 To build PCRE using static libraries only you must use --disable-shared when
436 configuring it. For example:
438 ./configure --prefix=/usr/gnu --disable-shared
440 Then run "make" in the usual way. Similarly, you can use --disable-static to
441 build only shared libraries.
444 Cross-compiling on Unix-like systems
445 ------------------------------------
447 You can specify CC and CFLAGS in the normal way to the "configure" command, in
448 order to cross-compile PCRE for some other host. However, you should NOT
449 specify --enable-rebuild-chartables, because if you do, the dftables.c source
450 file is compiled and run on the local host, in order to generate the inbuilt
451 character tables (the pcre_chartables.c file). This will probably not work,
452 because dftables.c needs to be compiled with the local compiler, not the cross
453 compiler.
455 When --enable-rebuild-chartables is not specified, pcre_chartables.c is created
456 by making a copy of pcre_chartables.c.dist, which is a default set of tables
457 that assumes ASCII code. Cross-compiling with the default tables should not be
458 a problem.
460 If you need to modify the character tables when cross-compiling, you should
461 move pcre_chartables.c.dist out of the way, then compile dftables.c by hand and
462 run it on the local host to make a new version of pcre_chartables.c.dist.
463 Then when you cross-compile PCRE this new version of the tables will be used.
466 Using HP's ANSI C++ compiler (aCC)
467 ----------------------------------
469 Unless C++ support is disabled by specifying the "--disable-cpp" option of the
470 "configure" script, you must include the "-AA" option in the CXXFLAGS
471 environment variable in order for the C++ components to compile correctly.
473 Also, note that the aCC compiler on PA-RISC platforms may have a defect whereby
474 needed libraries fail to get included when specifying the "-AA" compiler
475 option. If you experience unresolved symbols when linking the C++ programs,
476 use the workaround of specifying the following environment variable prior to
477 running the "configure" script:
479 CXXLDFLAGS="-lstd_v2 -lCsup_v2"
482 Using Sun's compilers for Solaris
483 ---------------------------------
485 A user reports that the following configurations work on Solaris 9 sparcv9 and
486 Solaris 9 x86 (32-bit):
488 Solaris 9 sparcv9: ./configure --disable-cpp CC=/bin/cc CFLAGS="-m64 -g"
489 Solaris 9 x86: ./configure --disable-cpp CC=/bin/cc CFLAGS="-g"
492 Using PCRE from MySQL
493 ---------------------
495 On systems where both PCRE and MySQL are installed, it is possible to make use
496 of PCRE from within MySQL, as an alternative to the built-in pattern matching.
497 There is a web page that tells you how to do this:
499 http://www.mysqludf.org/lib_mysqludf_preg/index.php
502 Making new tarballs
503 -------------------
505 The command "make dist" creates three PCRE tarballs, in tar.gz, tar.bz2, and
506 zip formats. The command "make distcheck" does the same, but then does a trial
507 build of the new distribution to ensure that it works.
509 If you have modified any of the man page sources in the doc directory, you
510 should first run the PrepareRelease script before making a distribution. This
511 script creates the .txt and HTML forms of the documentation from the man pages.
514 Testing PCRE
515 ------------
517 To test the basic PCRE library on a Unix system, run the RunTest script that is
518 created by the configuring process. There is also a script called RunGrepTest
519 that tests the options of the pcregrep command. If the C++ wrapper library is
520 built, three test programs called pcrecpp_unittest, pcre_scanner_unittest, and
521 pcre_stringpiece_unittest are also built.
523 Both the scripts and all the program tests are run if you obey "make check" or
524 "make test". For other systems, see the instructions in NON-UNIX-USE.
526 The RunTest script runs the pcretest test program (which is documented in its
527 own man page) on each of the testinput files in the testdata directory in
528 turn, and compares the output with the contents of the corresponding testoutput
529 files. A file called testtry is used to hold the main output from pcretest
530 (testsavedregex is also used as a working file). To run pcretest on just one of
531 the test files, give its number as an argument to RunTest, for example:
533 RunTest 2
535 The first test file can also be fed directly into the perltest.pl script to
536 check that Perl gives the same results. The only difference you should see is
537 in the first few lines, where the Perl version is given instead of the PCRE
538 version.
540 The second set of tests check pcre_fullinfo(), pcre_info(), pcre_study(),
541 pcre_copy_substring(), pcre_get_substring(), pcre_get_substring_list(), error
542 detection, and run-time flags that are specific to PCRE, as well as the POSIX
543 wrapper API. It also uses the debugging flags to check some of the internals of
544 pcre_compile().
546 If you build PCRE with a locale setting that is not the standard C locale, the
547 character tables may be different (see next paragraph). In some cases, this may
548 cause failures in the second set of tests. For example, in a locale where the
549 isprint() function yields TRUE for characters in the range 128-255, the use of
550 [:isascii:] inside a character class defines a different set of characters, and
551 this shows up in this test as a difference in the compiled code, which is being
552 listed for checking. Where the comparison test output contains [\x00-\x7f] the
553 test will contain [\x00-\xff], and similarly in some other cases. This is not a
554 bug in PCRE.
556 The third set of tests checks pcre_maketables(), the facility for building a
557 set of character tables for a specific locale and using them instead of the
558 default tables. The tests make use of the "fr_FR" (French) locale. Before
559 running the test, the script checks for the presence of this locale by running
560 the "locale" command. If that command fails, or if it doesn't include "fr_FR"
561 in the list of available locales, the third test cannot be run, and a comment
562 is output to say why. If running this test produces instances of the error
564 ** Failed to set locale "fr_FR"
566 in the comparison output, it means that locale is not available on your system,
567 despite being listed by "locale". This does not mean that PCRE is broken.
569 [If you are trying to run this test on Windows, you may be able to get it to
570 work by changing "fr_FR" to "french" everywhere it occurs. Alternatively, use
571 RunTest.bat. The version of RunTest.bat included with PCRE 7.4 and above uses
572 Windows versions of test 2. More info on using RunTest.bat is included in the
573 document entitled NON-UNIX-USE.]
575 The fourth test checks the UTF-8 support. It is not run automatically unless
576 PCRE is built with UTF-8 support. To do this you must set --enable-utf8 when
577 running "configure". This file can be also fed directly to the perltest.pl
578 script, provided you are running Perl 5.8 or higher.
580 The fifth test checks error handling with UTF-8 encoding, and internal UTF-8
581 features of PCRE that are not relevant to Perl.
583 The sixth test (which is Perl-5.10 compatible) checks the support for Unicode
584 character properties. It it not run automatically unless PCRE is built with
585 Unicode property support. To to this you must set --enable-unicode-properties
586 when running "configure".
588 The seventh, eighth, and ninth tests check the pcre_dfa_exec() alternative
589 matching function, in non-UTF-8 mode, UTF-8 mode, and UTF-8 mode with Unicode
590 property support, respectively. The eighth and ninth tests are not run
591 automatically unless PCRE is build with the relevant support.
593 The tenth test checks some internal offsets and code size features; it is run
594 only when the default "link size" of 2 is set (in other cases the sizes
595 change).
597 The eleventh test checks out features that are new in Perl 5.10, and the
598 twelfth test checks a number internals and non-Perl features concerned with
599 Unicode property support. It it not run automatically unless PCRE is built with
600 Unicode property support. To to this you must set --enable-unicode-properties
601 when running "configure".
604 Character tables
605 ----------------
607 For speed, PCRE uses four tables for manipulating and identifying characters
608 whose code point values are less than 256. The final argument of the
609 pcre_compile() function is a pointer to a block of memory containing the
610 concatenated tables. A call to pcre_maketables() can be used to generate a set
611 of tables in the current locale. If the final argument for pcre_compile() is
612 passed as NULL, a set of default tables that is built into the binary is used.
614 The source file called pcre_chartables.c contains the default set of tables. By
615 default, this is created as a copy of pcre_chartables.c.dist, which contains
616 tables for ASCII coding. However, if --enable-rebuild-chartables is specified
617 for ./configure, a different version of pcre_chartables.c is built by the
618 program dftables (compiled from dftables.c), which uses the ANSI C character
619 handling functions such as isalnum(), isalpha(), isupper(), islower(), etc. to
620 build the table sources. This means that the default C locale which is set for
621 your system will control the contents of these default tables. You can change
622 the default tables by editing pcre_chartables.c and then re-building PCRE. If
623 you do this, you should take care to ensure that the file does not get
624 automatically re-generated. The best way to do this is to move
625 pcre_chartables.c.dist out of the way and replace it with your customized
626 tables.
628 When the dftables program is run as a result of --enable-rebuild-chartables,
629 it uses the default C locale that is set on your system. It does not pay
630 attention to the LC_xxx environment variables. In other words, it uses the
631 system's default locale rather than whatever the compiling user happens to have
632 set. If you really do want to build a source set of character tables in a
633 locale that is specified by the LC_xxx variables, you can run the dftables
634 program by hand with the -L option. For example:
636 ./dftables -L pcre_chartables.c.special
638 The first two 256-byte tables provide lower casing and case flipping functions,
639 respectively. The next table consists of three 32-byte bit maps which identify
640 digits, "word" characters, and white space, respectively. These are used when
641 building 32-byte bit maps that represent character classes for code points less
642 than 256.
644 The final 256-byte table has bits indicating various character types, as
645 follows:
647 1 white space character
648 2 letter
649 4 decimal digit
650 8 hexadecimal digit
651 16 alphanumeric or '_'
652 128 regular expression metacharacter or binary zero
654 You should not alter the set of characters that contain the 128 bit, as that
655 will cause PCRE to malfunction.
658 File manifest
659 -------------
661 The distribution should contain the following files:
663 (A) Source files of the PCRE library functions and their headers:
665 dftables.c auxiliary program for building pcre_chartables.c
666 when --enable-rebuild-chartables is specified
668 pcre_chartables.c.dist a default set of character tables that assume ASCII
669 coding; used, unless --enable-rebuild-chartables is
670 specified, by copying to pcre_chartables.c
672 pcreposix.c )
673 pcre_compile.c )
674 pcre_config.c )
675 pcre_dfa_exec.c )
676 pcre_exec.c )
677 pcre_fullinfo.c )
678 pcre_get.c ) sources for the functions in the library,
679 pcre_globals.c ) and some internal functions that they use
680 pcre_info.c )
681 pcre_maketables.c )
682 pcre_newline.c )
683 pcre_ord2utf8.c )
684 pcre_refcount.c )
685 pcre_study.c )
686 pcre_tables.c )
687 pcre_try_flipped.c )
688 pcre_ucd.c )
689 pcre_valid_utf8.c )
690 pcre_version.c )
691 pcre_xclass.c )
692 pcre_printint.src ) debugging function that is #included in pcretest,
693 ) and can also be #included in pcre_compile()
694 pcre.h.in template for pcre.h when built by "configure"
695 pcreposix.h header for the external POSIX wrapper API
696 pcre_internal.h header for internal use
697 ucp.h header for Unicode property handling
699 config.h.in template for config.h, which is built by "configure"
701 pcrecpp.h public header file for the C++ wrapper
702 pcrecpparg.h.in template for another C++ header file
703 pcre_scanner.h public header file for C++ scanner functions
704 pcrecpp.cc )
705 pcre_scanner.cc ) source for the C++ wrapper library
707 pcre_stringpiece.h.in template for pcre_stringpiece.h, the header for the
708 C++ stringpiece functions
709 pcre_stringpiece.cc source for the C++ stringpiece functions
711 (B) Source files for programs that use PCRE:
713 pcredemo.c simple demonstration of coding calls to PCRE
714 pcregrep.c source of a grep utility that uses PCRE
715 pcretest.c comprehensive test program
717 (C) Auxiliary files:
719 132html script to turn "man" pages into HTML
720 AUTHORS information about the author of PCRE
721 ChangeLog log of changes to the code
722 CleanTxt script to clean nroff output for txt man pages
723 Detrail script to remove trailing spaces
724 HACKING some notes about the internals of PCRE
725 INSTALL generic installation instructions
726 LICENCE conditions for the use of PCRE
727 COPYING the same, using GNU's standard name
728 Makefile.in ) template for Unix Makefile, which is built by
729 ) "configure"
730 Makefile.am ) the automake input that was used to create
731 ) Makefile.in
732 NEWS important changes in this release
733 NON-UNIX-USE notes on building PCRE on non-Unix systems
734 PrepareRelease script to make preparations for "make dist"
735 README this file
736 RunTest a Unix shell script for running tests
737 RunGrepTest a Unix shell script for pcregrep tests
738 aclocal.m4 m4 macros (generated by "aclocal")
739 config.guess ) files used by libtool,
740 config.sub ) used only when building a shared library
741 configure a configuring shell script (built by autoconf)
742 configure.ac ) the autoconf input that was used to build
743 ) "configure" and config.h
744 depcomp ) script to find program dependencies, generated by
745 ) automake
746 doc/*.3 man page sources for PCRE
747 doc/*.1 man page sources for pcregrep and pcretest
748 doc/index.html.src the base HTML page
749 doc/html/* HTML documentation
750 doc/pcre.txt plain text version of the man pages
751 doc/pcretest.txt plain text documentation of test program
752 doc/perltest.txt plain text documentation of Perl test program
753 install-sh a shell script for installing files
754 libpcre.pc.in template for libpcre.pc for pkg-config
755 libpcreposix.pc.in template for libpcreposix.pc for pkg-config
756 libpcrecpp.pc.in template for libpcrecpp.pc for pkg-config
757 ltmain.sh file used to build a libtool script
758 missing ) common stub for a few missing GNU programs while
759 ) installing, generated by automake
760 mkinstalldirs script for making install directories
761 perltest.pl Perl test program
762 pcre-config.in source of script which retains PCRE information
763 pcrecpp_unittest.cc )
764 pcre_scanner_unittest.cc ) test programs for the C++ wrapper
765 pcre_stringpiece_unittest.cc )
766 testdata/testinput* test data for main library tests
767 testdata/testoutput* expected test results
768 testdata/grep* input and output for pcregrep tests
770 (D) Auxiliary files for cmake support
773 cmake/FindPackageHandleStandardArgs.cmake
774 cmake/FindReadline.cmake
775 CMakeLists.txt
776 config-cmake.h.in
778 (E) Auxiliary files for VPASCAL
780 makevp.bat
781 makevp_c.txt
782 makevp_l.txt
783 pcregexp.pas
785 (F) Auxiliary files for building PCRE "by hand"
787 pcre.h.generic ) a version of the public PCRE header file
788 ) for use in non-"configure" environments
789 config.h.generic ) a version of config.h for use in non-"configure"
790 ) environments
792 (F) Miscellaneous
794 RunTest.bat a script for running tests under Windows
796 Philip Hazel
797 Email local part: ph10
798 Email domain: cam.ac.uk
799 Last updated: 19 October 2009


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