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1  README file for PCRE (Perl-compatible regular expressions)  README file for PCRE (Perl-compatible regular expression library)
2  ----------------------------------------------------------  -----------------------------------------------------------------
3    
4  *******************************************************************************  The latest release of PCRE is always available in three alternative formats
5  *           IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00           *  from:
 *                                                                             *  
 * Please note that there has been a change in the API such that a larger      *  
 * ovector is required at matching time, to provide some additional workspace. *  
 * The new man page has details. This change was necessary in order to support *  
 * some of the new functionality in Perl 5.005.                                *  
 *******************************************************************************  
6    
7  The distribution should contain the following files:    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    ChangeLog         log of changes to the code    ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-xxx.zip
10    Makefile          for building PCRE  
11    README            this file  There is a mailing list for discussion about the development of PCRE at
12    RunTest           a shell script for running tests  
13    Tech.Notes        notes on the encoding    pcre-dev@exim.org
14    pcre.3            man page for the functions  
15    pcreposix.3       man page for the POSIX wrapper API  Please read the NEWS file if you are upgrading from a previous release.
16    maketables.c      auxiliary program for building chartables.c  The contents of this README file are:
17    study.c           ) source of  
18    pcre.c            )   the functions    The PCRE APIs
19    pcreposix.c       )    Documentation for PCRE
20    pcre.h            header for the external API    Contributions by users of PCRE
21    pcreposix.h       header for the external POSIX wrapper API    Building PCRE on non-Unix systems
22    internal.h        header for internal use    Building PCRE on Unix-like systems
23    pcretest.c        test program    Retrieving configuration information on Unix-like systems
24    pgrep.1           man page for pgrep    Shared libraries on Unix-like systems
25    pgrep.c           source of a grep utility that uses PCRE    Cross-compiling on Unix-like systems
26    perltest          Perl test program    Using HP's ANSI C++ compiler (aCC)
27    testinput         test data, compatible with Perl 5.004 and 5.005    Making new tarballs
28    testinput2        test data for error messages and non-Perl things    Testing PCRE
29    testinput3        test data, compatible with Perl 5.005    Character tables
30    testoutput        test results corresponding to testinput    File manifest
31    testoutput2       test results corresponding to testinput2  
32    testoutput3       test results corresponding to testinpug3  
33    The PCRE APIs
34  To build PCRE, edit Makefile for your system (it is a fairly simple make file,  -------------
35  and there are some comments at the top) and then run it. It builds two  
36  libraries called libpcre.a and libpcreposix.a, a test program called pcretest,  PCRE is written in C, and it has its own API. The distribution also includes a
37  and the pgrep command.  set of C++ wrapper functions (see the pcrecpp man page for details), courtesy
38    of Google Inc.
39  To test PCRE, run the RunTest script in the pcre directory. This runs pcretest  
40  on each of the testinput files in turn, and compares the output with the  In addition, there is a set of C wrapper functions that are based on the POSIX
41  contents of the corresponding testoutput file. A file called testtry is used to  regular expression API (see the pcreposix man page). These end up in the
42  hold the output from pcretest (which is documented below).  library called libpcreposix. Note that this just provides a POSIX calling
43    interface to PCRE; the regular expressions themselves still follow Perl syntax
44  To run pcretest on just one of the test files, give its number as an argument  and semantics. The POSIX API is restricted, and does not give full access to
45  to RunTest, for example:  all of PCRE's facilities.
46    
47    RunTest 3  The header file for the POSIX-style functions is called pcreposix.h. The
48    official POSIX name is regex.h, but I did not want to risk possible problems
49  The first and third test files can also be fed directly into the perltest  with existing files of that name by distributing it that way. To use PCRE with
50  program to check that Perl gives the same results. The third file requires the  an existing program that uses the POSIX API, pcreposix.h will have to be
51  additional features of release 5.005, which is why it is kept separate from the  renamed or pointed at by a link.
52  main test input, which needs only Perl 5.004. In the long run, when 5.005 is  
53  widespread, these two test files may get amalgamated.  If you are using the POSIX interface to PCRE and there is already a POSIX regex
54    library installed on your system, as well as worrying about the regex.h header
55  The second set of tests check pcre_info(), pcre_study(), error detection and  file (as mentioned above), you must also take care when linking programs to
56  run-time flags that are specific to PCRE, as well as the POSIX wrapper API.  ensure that they link with PCRE's libpcreposix library. Otherwise they may pick
57    up the POSIX functions of the same name from the other library.
58  To install PCRE, copy libpcre.a to any suitable library directory (e.g.  
59  /usr/local/lib), pcre.h to any suitable include directory (e.g.  One way of avoiding this confusion is to compile PCRE with the addition of
60  /usr/local/include), and pcre.3 to any suitable man directory (e.g.  -Dregcomp=PCREregcomp (and similarly for the other POSIX functions) to the
61  /usr/local/man/man3).  compiler flags (CFLAGS if you are using "configure" -- see below). This has the
62    effect of renaming the functions so that the names no longer clash. Of course,
63  To install the pgrep command, copy it to any suitable binary directory, (e.g.  you have to do the same thing for your applications, or write them using the
64  /usr/local/bin) and pgrep.1 to any suitable man directory (e.g.  new names.
65  /usr/local/man/man1).  
66    
67  PCRE has its own native API, but a set of "wrapper" functions that are based on  Documentation for PCRE
68  the POSIX API are also supplied in the library libpcreposix.a. Note that this  ----------------------
69  just provides a POSIX calling interface to PCRE: the regular expressions  
70  themselves still follow Perl syntax and semantics. The header file  If you install PCRE in the normal way on a Unix-like system, you will end up
71  for the POSIX-style functions is called pcreposix.h. The official POSIX name is  with a set of man pages whose names all start with "pcre". The one that is just
72  regex.h, but I didn't want to risk possible problems with existing files of  called "pcre" lists all the others. In addition to these man pages, the PCRE
73  that name by distributing it that way. To use it with an existing program that  documentation is supplied in two other forms:
74  uses the POSIX API, it will have to be renamed or pointed at by a link.  
75      1. There are files called doc/pcre.txt, doc/pcregrep.txt, and
76         doc/pcretest.txt in the source distribution. The first of these is a
77         concatenation of the text forms of all the section 3 man pages except
78         those that summarize individual functions. The other two are the text
79         forms of the section 1 man pages for the pcregrep and pcretest commands.
80         These text forms are provided for ease of scanning with text editors or
81         similar tools. They are installed in <prefix>/share/doc/pcre, where
82         <prefix> is the installation prefix (defaulting to /usr/local).
83    
84      2. A set of files containing all the documentation in HTML form, hyperlinked
85         in various ways, and rooted in a file called index.html, is distributed in
86         doc/html and installed in <prefix>/share/doc/pcre/html.
87    
88    
89    Contributions by users of PCRE
90    ------------------------------
91    
92    You can find contributions from PCRE users in the directory
93    
94      ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/Contrib
95    
96    There is a README file giving brief descriptions of what they are. Some are
97    complete in themselves; others are pointers to URLs containing relevant files.
98    Some of this material is likely to be well out-of-date. Several of the earlier
99    contributions provided support for compiling PCRE on various flavours of
100    Windows (I myself do not use Windows). Nowadays there is more Windows support
101    in the standard distribution, so these contibutions have been archived.
102    
103    
104    Building PCRE on non-Unix systems
105    ---------------------------------
106    
107    For a non-Unix system, please read the comments in the file NON-UNIX-USE,
108    though if your system supports the use of "configure" and "make" you may be
109    able to build PCRE in the same way as for Unix-like systems. PCRE can also be
110    configured in many platform environments using the GUI facility of CMake's
111    CMakeSetup. It creates Makefiles, solution files, etc.
112    
113    PCRE has been compiled on many different operating systems. It should be
114    straightforward to build PCRE on any system that has a Standard C compiler and
115    library, because it uses only Standard C functions.
116    
117    
118    Building PCRE on Unix-like systems
119    ----------------------------------
120    
121    If you are using HP's ANSI C++ compiler (aCC), please see the special note
122    in the section entitled "Using HP's ANSI C++ compiler (aCC)" below.
123    
124    The following instructions assume the use of the widely used "configure, make,
125    make install" process. There is also support for CMake in the PCRE
126    distribution; there are some comments about using CMake in the NON-UNIX-USE
127    file, though it can also be used in Unix-like systems.
128    
129    To build PCRE on a Unix-like system, first run the "configure" command from the
130    PCRE distribution directory, with your current directory set to the directory
131    where you want the files to be created. This command is a standard GNU
132    "autoconf" configuration script, for which generic instructions are supplied in
133    the file INSTALL.
134    
135    Most commonly, people build PCRE within its own distribution directory, and in
136    this case, on many systems, just running "./configure" is sufficient. However,
137    the usual methods of changing standard defaults are available. For example:
138    
139    CFLAGS='-O2 -Wall' ./configure --prefix=/opt/local
140    
141    specifies that the C compiler should be run with the flags '-O2 -Wall' instead
142    of the default, and that "make install" should install PCRE under /opt/local
143    instead of the default /usr/local.
144    
145    If you want to build in a different directory, just run "configure" with that
146    directory as current. For example, suppose you have unpacked the PCRE source
147    into /source/pcre/pcre-xxx, but you want to build it in /build/pcre/pcre-xxx:
148    
149    cd /build/pcre/pcre-xxx
150    /source/pcre/pcre-xxx/configure
151    
152    PCRE is written in C and is normally compiled as a C library. However, it is
153    possible to build it as a C++ library, though the provided building apparatus
154    does not have any features to support this.
155    
156    There are some optional features that can be included or omitted from the PCRE
157    library. You can read more about them in the pcrebuild man page.
158    
159    . If you want to suppress the building of the C++ wrapper library, you can add
160      --disable-cpp to the "configure" command. Otherwise, when "configure" is run,
161      it will try to find a C++ compiler and C++ header files, and if it succeeds,
162      it will try to build the C++ wrapper.
163    
164    . If you want to make use of the support for UTF-8 character strings in PCRE,
165      you must add --enable-utf8 to the "configure" command. Without it, the code
166      for handling UTF-8 is not included in the library. (Even when included, it
167      still has to be enabled by an option at run time.)
168    
169    . If, in addition to support for UTF-8 character strings, you want to include
170      support for the \P, \p, and \X sequences that recognize Unicode character
171      properties, you must add --enable-unicode-properties to the "configure"
172      command. This adds about 30K to the size of the library (in the form of a
173      property table); only the basic two-letter properties such as Lu are
174      supported.
175    
176    . You can build PCRE to recognize either CR or LF or the sequence CRLF or any
177      of the preceding, or any of the Unicode newline sequences as indicating the
178      end of a line. Whatever you specify at build time is the default; the caller
179      of PCRE can change the selection at run time. The default newline indicator
180      is a single LF character (the Unix standard). You can specify the default
181      newline indicator by adding --enable-newline-is-cr or --enable-newline-is-lf
182      or --enable-newline-is-crlf or --enable-newline-is-anycrlf or
183      --enable-newline-is-any to the "configure" command, respectively.
184    
185      If you specify --enable-newline-is-cr or --enable-newline-is-crlf, some of
186      the standard tests will fail, because the lines in the test files end with
187      LF. Even if the files are edited to change the line endings, there are likely
188      to be some failures. With --enable-newline-is-anycrlf or
189      --enable-newline-is-any, many tests should succeed, but there may be some
190      failures.
191    
192    . By default, the sequence \R in a pattern matches any Unicode line ending
193      sequence. This is independent of the option specifying what PCRE considers to
194      be the end of a line (see above). However, the caller of PCRE can restrict \R
195      to match only CR, LF, or CRLF. You can make this the default by adding
196      --enable-bsr-anycrlf to the "configure" command (bsr = "backslash R").
197    
198    . When called via the POSIX interface, PCRE uses malloc() to get additional
199      storage for processing capturing parentheses if there are more than 10 of
200      them in a pattern. You can increase this threshold by setting, for example,
201    
202      --with-posix-malloc-threshold=20
203    
204      on the "configure" command.
205    
206    . PCRE has a counter that can be set to limit the amount of resources it uses.
207      If the limit is exceeded during a match, the match fails. The default is ten
208      million. You can change the default by setting, for example,
209    
210      --with-match-limit=500000
211    
212      on the "configure" command. This is just the default; individual calls to
213      pcre_exec() can supply their own value. There is more discussion on the
214      pcreapi man page.
215    
216    . There is a separate counter that limits the depth of recursive function calls
217      during a matching process. This also has a default of ten million, which is
218      essentially "unlimited". You can change the default by setting, for example,
219    
220      --with-match-limit-recursion=500000
221    
222      Recursive function calls use up the runtime stack; running out of stack can
223      cause programs to crash in strange ways. There is a discussion about stack
224      sizes in the pcrestack man page.
225    
226    . The default maximum compiled pattern size is around 64K. You can increase
227      this by adding --with-link-size=3 to the "configure" command. You can
228      increase it even more by setting --with-link-size=4, but this is unlikely
229      ever to be necessary. Increasing the internal link size will reduce
230      performance.
231    
232    . You can build PCRE so that its internal match() function that is called from
233      pcre_exec() does not call itself recursively. Instead, it uses memory blocks
234      obtained from the heap via the special functions pcre_stack_malloc() and
235      pcre_stack_free() to save data that would otherwise be saved on the stack. To
236      build PCRE like this, use
237    
238      --disable-stack-for-recursion
239    
240      on the "configure" command. PCRE runs more slowly in this mode, but it may be
241      necessary in environments with limited stack sizes. This applies only to the
242      pcre_exec() function; it does not apply to pcre_dfa_exec(), which does not
243      use deeply nested recursion. There is a discussion about stack sizes in the
244      pcrestack man page.
245    
246    . For speed, PCRE uses four tables for manipulating and identifying characters
247      whose code point values are less than 256. By default, it uses a set of
248      tables for ASCII encoding that is part of the distribution. If you specify
249    
250      --enable-rebuild-chartables
251    
252      a program called dftables is compiled and run in the default C locale when
253      you obey "make". It builds a source file called pcre_chartables.c. If you do
254      not specify this option, pcre_chartables.c is created as a copy of
255      pcre_chartables.c.dist. See "Character tables" below for further information.
256    
257    . It is possible to compile PCRE for use on systems that use EBCDIC as their
258      default character code (as opposed to ASCII) by specifying
259    
260      --enable-ebcdic
261    
262      This automatically implies --enable-rebuild-chartables (see above).
263    
264    . It is possible to compile pcregrep to use libz and/or libbz2, in order to
265      read .gz and .bz2 files (respectively), by specifying one or both of
266    
267      --enable-pcregrep-libz
268      --enable-pcregrep-libbz2
269    
270      Of course, the relevant libraries must be installed on your system.
271    
272    . It is possible to compile pcretest so that it links with the libreadline
273      library, by specifying
274    
275      --enable-pcretest-libreadline
276    
277      If this is done, when pcretest's input is from a terminal, it reads it using
278      the readline() function. This provides line-editing and history facilities.
279      Note that libreadline is GPL-licenced, so if you distribute a binary of
280      pcretest linked in this way, there may be licensing issues.
281    
282      Setting this option causes the -lreadline option to be added to the pcretest
283      build. In many operating environments with a sytem-installed readline
284      library this is sufficient. However, in some environments (e.g. if an
285      unmodified distribution version of readline is in use), it may be necessary
286      to specify something like LIBS="-lncurses" as well. This is because, to quote
287      the readline INSTALL, "Readline uses the termcap functions, but does not link
288      with the termcap or curses library itself, allowing applications which link
289      with readline the to choose an appropriate library." If you get error
290      messages about missing functions tgetstr, tgetent, tputs, tgetflag, or tgoto,
291      this is the problem, and linking with the ncurses library should fix it.
292    
293    The "configure" script builds the following files for the basic C library:
294    
295    . Makefile is the makefile that builds the library
296    . config.h contains build-time configuration options for the library
297    . pcre.h is the public PCRE header file
298    . pcre-config is a script that shows the settings of "configure" options
299    . libpcre.pc is data for the pkg-config command
300    . libtool is a script that builds shared and/or static libraries
301    . RunTest is a script for running tests on the basic C library
302    . RunGrepTest is a script for running tests on the pcregrep command
303    
304    Versions of config.h and pcre.h are distributed in the PCRE tarballs under
305    the names config.h.generic and pcre.h.generic. These are provided for the
306    benefit of those who have to built PCRE without the benefit of "configure". If
307    you use "configure", the .generic versions are not used.
308    
309    If a C++ compiler is found, the following files are also built:
310    
311    . libpcrecpp.pc is data for the pkg-config command
312    . pcrecpparg.h is a header file for programs that call PCRE via the C++ wrapper
313    . pcre_stringpiece.h is the header for the C++ "stringpiece" functions
314    
315    The "configure" script also creates config.status, which is an executable
316    script that can be run to recreate the configuration, and config.log, which
317    contains compiler output from tests that "configure" runs.
318    
319    Once "configure" has run, you can run "make". It builds two libraries, called
320    libpcre and libpcreposix, a test program called pcretest, and the pcregrep
321    command. If a C++ compiler was found on your system, "make" also builds the C++
322    wrapper library, which is called libpcrecpp, and some test programs called
323    pcrecpp_unittest, pcre_scanner_unittest, and pcre_stringpiece_unittest.
324    Building the C++ wrapper can be disabled by adding --disable-cpp to the
325    "configure" command.
326    
327    The command "make check" runs all the appropriate tests. Details of the PCRE
328    tests are given below in a separate section of this document.
329    
330    You can use "make install" to install PCRE into live directories on your
331    system. The following are installed (file names are all relative to the
332    <prefix> that is set when "configure" is run):
333    
334      Commands (bin):
335        pcretest
336        pcregrep
337        pcre-config
338    
339      Libraries (lib):
340        libpcre
341        libpcreposix
342        libpcrecpp (if C++ support is enabled)
343    
344      Configuration information (lib/pkgconfig):
345        libpcre.pc
346        libpcrecpp.pc (if C++ support is enabled)
347    
348      Header files (include):
349        pcre.h
350        pcreposix.h
351        pcre_scanner.h      )
352        pcre_stringpiece.h  ) if C++ support is enabled
353        pcrecpp.h           )
354        pcrecpparg.h        )
355    
356      Man pages (share/man/man{1,3}):
357        pcregrep.1
358        pcretest.1
359        pcre.3
360        pcre*.3 (lots more pages, all starting "pcre")
361    
362      HTML documentation (share/doc/pcre/html):
363        index.html
364        *.html (lots more pages, hyperlinked from index.html)
365    
366      Text file documentation (share/doc/pcre):
367        AUTHORS
368        COPYING
369        ChangeLog
370        LICENCE
371        NEWS
372        README
373        pcre.txt       (a concatenation of the man(3) pages)
374        pcretest.txt   the pcretest man page
375        pcregrep.txt   the pcregrep man page
376    
377    If you want to remove PCRE from your system, you can run "make uninstall".
378    This removes all the files that "make install" installed. However, it does not
379    remove any directories, because these are often shared with other programs.
380    
381    
382    Retrieving configuration information on Unix-like systems
383    ---------------------------------------------------------
384    
385    Running "make install" installs the command pcre-config, which can be used to
386    recall information about the PCRE configuration and installation. For example:
387    
388      pcre-config --version
389    
390    prints the version number, and
391    
392      pcre-config --libs
393    
394    outputs information about where the library is installed. This command can be
395    included in makefiles for programs that use PCRE, saving the programmer from
396    having to remember too many details.
397    
398    The pkg-config command is another system for saving and retrieving information
399    about installed libraries. Instead of separate commands for each library, a
400    single command is used. For example:
401    
402      pkg-config --cflags pcre
403    
404    The data is held in *.pc files that are installed in a directory called
405    <prefix>/lib/pkgconfig.
406    
407    
408    Shared libraries on Unix-like systems
409    -------------------------------------
410    
411    The default distribution builds PCRE as shared libraries and static libraries,
412    as long as the operating system supports shared libraries. Shared library
413    support relies on the "libtool" script which is built as part of the
414    "configure" process.
415    
416    The libtool script is used to compile and link both shared and static
417    libraries. They are placed in a subdirectory called .libs when they are newly
418    built. The programs pcretest and pcregrep are built to use these uninstalled
419    libraries (by means of wrapper scripts in the case of shared libraries). When
420    you use "make install" to install shared libraries, pcregrep and pcretest are
421    automatically re-built to use the newly installed shared libraries before being
422    installed themselves. However, the versions left in the build directory still
423    use the uninstalled libraries.
424    
425    To build PCRE using static libraries only you must use --disable-shared when
426    configuring it. For example:
427    
428    ./configure --prefix=/usr/gnu --disable-shared
429    
430    Then run "make" in the usual way. Similarly, you can use --disable-static to
431    build only shared libraries.
432    
433    
434    Cross-compiling on Unix-like systems
435    ------------------------------------
436    
437    You can specify CC and CFLAGS in the normal way to the "configure" command, in
438    order to cross-compile PCRE for some other host. However, you should NOT
439    specify --enable-rebuild-chartables, because if you do, the dftables.c source
440    file is compiled and run on the local host, in order to generate the inbuilt
441    character tables (the pcre_chartables.c file). This will probably not work,
442    because dftables.c needs to be compiled with the local compiler, not the cross
443    compiler.
444    
445    When --enable-rebuild-chartables is not specified, pcre_chartables.c is created
446    by making a copy of pcre_chartables.c.dist, which is a default set of tables
447    that assumes ASCII code. Cross-compiling with the default tables should not be
448    a problem.
449    
450    If you need to modify the character tables when cross-compiling, you should
451    move pcre_chartables.c.dist out of the way, then compile dftables.c by hand and
452    run it on the local host to make a new version of pcre_chartables.c.dist.
453    Then when you cross-compile PCRE this new version of the tables will be used.
454    
455    
456    Using HP's ANSI C++ compiler (aCC)
457    ----------------------------------
458    
459    Unless C++ support is disabled by specifying the "--disable-cpp" option of the
460    "configure" script, you must include the "-AA" option in the CXXFLAGS
461    environment variable in order for the C++ components to compile correctly.
462    
463    Also, note that the aCC compiler on PA-RISC platforms may have a defect whereby
464    needed libraries fail to get included when specifying the "-AA" compiler
465    option. If you experience unresolved symbols when linking the C++ programs,
466    use the workaround of specifying the following environment variable prior to
467    running the "configure" script:
468    
469      CXXLDFLAGS="-lstd_v2 -lCsup_v2"
470    
471    
472    Making new tarballs
473    -------------------
474    
475    The command "make dist" creates three PCRE tarballs, in tar.gz, tar.bz2, and
476    zip formats. The command "make distcheck" does the same, but then does a trial
477    build of the new distribution to ensure that it works.
478    
479    If you have modified any of the man page sources in the doc directory, you
480    should first run the PrepareRelease script before making a distribution. This
481    script creates the .txt and HTML forms of the documentation from the man pages.
482    
483    
484    Testing PCRE
485    ------------
486    
487    To test the basic PCRE library on a Unix system, run the RunTest script that is
488    created by the configuring process. There is also a script called RunGrepTest
489    that tests the options of the pcregrep command. If the C++ wrapper library is
490    built, three test programs called pcrecpp_unittest, pcre_scanner_unittest, and
491    pcre_stringpiece_unittest are also built.
492    
493    Both the scripts and all the program tests are run if you obey "make check" or
494    "make test". For other systems, see the instructions in NON-UNIX-USE.
495    
496    The RunTest script runs the pcretest test program (which is documented in its
497    own man page) on each of the testinput files in the testdata directory in
498    turn, and compares the output with the contents of the corresponding testoutput
499    files. A file called testtry is used to hold the main output from pcretest
500    (testsavedregex is also used as a working file). To run pcretest on just one of
501    the test files, give its number as an argument to RunTest, for example:
502    
503      RunTest 2
504    
505    The first test file can also be fed directly into the perltest.pl script to
506    check that Perl gives the same results. The only difference you should see is
507    in the first few lines, where the Perl version is given instead of the PCRE
508    version.
509    
510    The second set of tests check pcre_fullinfo(), pcre_info(), pcre_study(),
511    pcre_copy_substring(), pcre_get_substring(), pcre_get_substring_list(), error
512    detection, and run-time flags that are specific to PCRE, as well as the POSIX
513    wrapper API. It also uses the debugging flags to check some of the internals of
514    pcre_compile().
515    
516    If you build PCRE with a locale setting that is not the standard C locale, the
517    character tables may be different (see next paragraph). In some cases, this may
518    cause failures in the second set of tests. For example, in a locale where the
519    isprint() function yields TRUE for characters in the range 128-255, the use of
520    [:isascii:] inside a character class defines a different set of characters, and
521    this shows up in this test as a difference in the compiled code, which is being
522    listed for checking. Where the comparison test output contains [\x00-\x7f] the
523    test will contain [\x00-\xff], and similarly in some other cases. This is not a
524    bug in PCRE.
525    
526    The third set of tests checks pcre_maketables(), the facility for building a
527    set of character tables for a specific locale and using them instead of the
528    default tables. The tests make use of the "fr_FR" (French) locale. Before
529    running the test, the script checks for the presence of this locale by running
530    the "locale" command. If that command fails, or if it doesn't include "fr_FR"
531    in the list of available locales, the third test cannot be run, and a comment
532    is output to say why. If running this test produces instances of the error
533    
534      ** Failed to set locale "fr_FR"
535    
536    in the comparison output, it means that locale is not available on your system,
537    despite being listed by "locale". This does not mean that PCRE is broken.
538    
539    [If you are trying to run this test on Windows, you may be able to get it to
540    work by changing "fr_FR" to "french" everywhere it occurs. Alternatively, use
541    RunTest.bat. The version of RunTest.bat included with PCRE 7.4 and above uses
542    Windows versions of test 2. More info on using RunTest.bat is included in the
543    document entitled NON-UNIX-USE.]
544    
545    The fourth test checks the UTF-8 support. It is not run automatically unless
546    PCRE is built with UTF-8 support. To do this you must set --enable-utf8 when
547    running "configure". This file can be also fed directly to the perltest script,
548    provided you are running Perl 5.8 or higher. (For Perl 5.6, a small patch,
549    commented in the script, can be be used.)
550    
551    The fifth test checks error handling with UTF-8 encoding, and internal UTF-8
552    features of PCRE that are not relevant to Perl.
553    
554    The sixth test checks the support for Unicode character properties. It it not
555    run automatically unless PCRE is built with Unicode property support. To to
556    this you must set --enable-unicode-properties when running "configure".
557    
558    The seventh, eighth, and ninth tests check the pcre_dfa_exec() alternative
559    matching function, in non-UTF-8 mode, UTF-8 mode, and UTF-8 mode with Unicode
560    property support, respectively. The eighth and ninth tests are not run
561    automatically unless PCRE is build with the relevant support.
562    
563    
564  Character tables  Character tables
565  ----------------  ----------------
566    
567  PCRE uses four tables for manipulating and identifying characters. These are  For speed, PCRE uses four tables for manipulating and identifying characters
568  compiled from a source file called chartables.c. This is not supplied in  whose code point values are less than 256. The final argument of the
569  the distribution, but is built by the program maketables (compiled from  pcre_compile() function is a pointer to a block of memory containing the
570  maketables.c), which uses the ANSI C character handling functions such as  concatenated tables. A call to pcre_maketables() can be used to generate a set
571  isalnum(), isalpha(), isupper(), islower(), etc. to build the table sources.  of tables in the current locale. If the final argument for pcre_compile() is
572  This means that the default C locale set in your system may affect the contents  passed as NULL, a set of default tables that is built into the binary is used.
573  of the tables. You can change the tables by editing chartables.c and then  
574  re-building PCRE. If you do this, you should probably also edit Makefile to  The source file called pcre_chartables.c contains the default set of tables. By
575  ensure that the file doesn't ever get re-generated.  default, this is created as a copy of pcre_chartables.c.dist, which contains
576    tables for ASCII coding. However, if --enable-rebuild-chartables is specified
577  The first two tables pcre_lcc[] and pcre_fcc[] provide lower casing and a  for ./configure, a different version of pcre_chartables.c is built by the
578  case flipping functions, respectively. The pcre_cbits[] table consists of four  program dftables (compiled from dftables.c), which uses the ANSI C character
579  32-byte bit maps which identify digits, letters, "word" characters, and white  handling functions such as isalnum(), isalpha(), isupper(), islower(), etc. to
580  space, respectively. These are used when building 32-byte bit maps that  build the table sources. This means that the default C locale which is set for
581  represent character classes.  your system will control the contents of these default tables. You can change
582    the default tables by editing pcre_chartables.c and then re-building PCRE. If
583    you do this, you should take care to ensure that the file does not get
584    automatically re-generated. The best way to do this is to move
585    pcre_chartables.c.dist out of the way and replace it with your customized
586    tables.
587    
588    When the dftables program is run as a result of --enable-rebuild-chartables,
589    it uses the default C locale that is set on your system. It does not pay
590    attention to the LC_xxx environment variables. In other words, it uses the
591    system's default locale rather than whatever the compiling user happens to have
592    set. If you really do want to build a source set of character tables in a
593    locale that is specified by the LC_xxx variables, you can run the dftables
594    program by hand with the -L option. For example:
595    
596      ./dftables -L pcre_chartables.c.special
597    
598    The first two 256-byte tables provide lower casing and case flipping functions,
599    respectively. The next table consists of three 32-byte bit maps which identify
600    digits, "word" characters, and white space, respectively. These are used when
601    building 32-byte bit maps that represent character classes for code points less
602    than 256.
603    
604  The pcre_ctypes[] table has bits indicating various character types, as  The final 256-byte table has bits indicating various character types, as
605  follows:  follows:
606    
607      1   white space character      1   white space character
# Line 113  You should not alter the set of characte Line 615  You should not alter the set of characte
615  will cause PCRE to malfunction.  will cause PCRE to malfunction.
616    
617    
618  The pcretest program  File manifest
619  --------------------  -------------
620    
621    The distribution should contain the following files:
622    
623  This program is intended for testing PCRE, but it can also be used for  (A) Source files of the PCRE library functions and their headers:
 experimenting with regular expressions.  
624    
625  If it is given two filename arguments, it reads from the first and writes to    dftables.c              auxiliary program for building pcre_chartables.c
626  the second. If it is given only one filename argument, it reads from that file                              when --enable-rebuild-chartables is specified
 and writes to stdout. Otherwise, it reads from stdin and writes to stdout, and  
 prompts for each line of input.  
   
 The program handles any number of sets of input on a single input file. Each  
 set starts with a regular expression, and continues with any number of data  
 lines to be matched against the pattern. An empty line signals the end of the  
 set. The regular expressions are given enclosed in any non-alphameric  
 delimiters, for example  
   
   /(a|bc)x+yz/  
   
 and may be followed by i, m, s, or x to set the PCRE_CASELESS, PCRE_MULTILINE,  
 PCRE_DOTALL, or PCRE_EXTENDED options, respectively. These options have the  
 same effect as they do in Perl.  
   
 There are also some upper case options that do not match Perl options: /A, /E,  
 and /X set PCRE_ANCHORED, PCRE_DOLLAR_ENDONLY, and PCRE_EXTRA respectively.  
 The /D option is a PCRE debugging feature. It causes the internal form of  
 compiled regular expressions to be output after compilation. The /S option  
 causes pcre_study() to be called after the expression has been compiled, and  
 the results used when the expression is matched.  
   
 Finally, the /P option causes pcretest to call PCRE via the POSIX wrapper API  
 rather than its native API. When this is done, all other options except /i and  
 /m are ignored. REG_ICASE is set if /i is present, and REG_NEWLINE is set if /m  
 is present. The wrapper functions force PCRE_DOLLAR_ENDONLY always, and  
 PCRE_DOTALL unless REG_NEWLINE is set.  
   
 A regular expression can extend over several lines of input; the newlines are  
 included in it. See the testinput files for many examples.  
   
 Before each data line is passed to pcre_exec(), leading and trailing whitespace  
 is removed, and it is then scanned for \ escapes. The following are recognized:  
   
   \a     alarm (= BEL)  
   \b     backspace  
   \e     escape  
   \f     formfeed  
   \n     newline  
   \r     carriage return  
   \t     tab  
   \v     vertical tab  
   \nnn   octal character (up to 3 octal digits)  
   \xhh   hexadecimal character (up to 2 hex digits)  
   
   \A     pass the PCRE_ANCHORED option to pcre_exec()  
   \B     pass the PCRE_NOTBOL option to pcre_exec()  
   \Odd   set the size of the output vector passed to pcre_exec() to dd  
            (any number of decimal digits)  
   \Z     pass the PCRE_NOTEOL option to pcre_exec()  
   
 A backslash followed by anything else just escapes the anything else. If the  
 very last character is a backslash, it is ignored. This gives a way of passing  
 an empty line as data, since a real empty line terminates the data input.  
   
 If /P was present on the regex, causing the POSIX wrapper API to be used, only  
 \B, and \Z have any effect, causing REG_NOTBOL and REG_NOTEOL to be passed to  
 regexec() respectively.  
   
 When a match succeeds, pcretest outputs the list of identified substrings that  
 pcre_exec() returns, starting with number 0 for the string that matched the  
 whole pattern. Here is an example of an interactive pcretest run.  
   
   $ pcretest  
   Testing Perl-Compatible Regular Expressions  
   PCRE version 0.90 08-Sep-1997  
   
     re> /^abc(\d+)/  
   data> abc123  
     0: abc123  
     1: 123  
   data> xyz  
   No match  
   
 Note that while patterns can be continued over several lines (a plain ">"  
 prompt is used for continuations), data lines may not. However newlines can be  
 included in data by means of the \n escape.  
   
 If the -p option is given to pcretest, it is equivalent to adding /P to each  
 regular expression: the POSIX wrapper API is used to call PCRE. None of the  
 following flags has any effect in this case.  
   
 If the option -d is given to pcretest, it is equivalent to adding /D to each  
 regular expression: the internal form is output after compilation.  
   
 If the option -i (for "information") is given to pcretest, it calls pcre_info()  
 after compiling an expression, and outputs the information it gets back. If the  
 pattern is studied, the results of that are also output.  
   
 If the option -s is given to pcretest, it outputs the size of each compiled  
 pattern after it has been compiled.  
   
 If the -t option is given, each compile, study, and match is run 10000 times  
 while being timed, and the resulting time per compile or match is output in  
 milliseconds. Do not set -t with -s, because you will then get the size output  
 10000 times and the timing will be distorted. If you want to change the number  
 of repetitions used for timing, edit the definition of LOOPREPEAT at the top of  
 pcretest.c  
   
   
   
 The perltest program  
 --------------------  
   
 The perltest program tests Perl's regular expressions; it has the same  
 specification as pcretest, and so can be given identical input, except that  
 input patterns can be followed only by Perl's lower case options. The contents  
 of testinput and testinput3 meet this condition.  
   
 The data lines are processed as Perl strings, so if they contain $ or @  
 characters, these have to be escaped. For this reason, all such characters in  
 the testinput file are escaped so that it can be used for perltest as well as  
 for pcretest, and the special upper case options such as /A that pcretest  
 recognizes are not used in this file. The output should be identical, apart  
 from the initial identifying banner.  
   
 The testinput2 file is not suitable for feeding to Perltest, since it does  
 make use of the special upper case options and escapes that pcretest uses to  
 test some features of PCRE. It also contains malformed regular expressions, in  
 order to check that PCRE diagnoses them correctly.  
627    
628  Philip Hazel <ph10@cam.ac.uk>    pcre_chartables.c.dist  a default set of character tables that assume ASCII
629  September 1998                              coding; used, unless --enable-rebuild-chartables is
630                                specified, by copying to pcre_chartables.c
631    
632      pcreposix.c             )
633      pcre_compile.c          )
634      pcre_config.c           )
635      pcre_dfa_exec.c         )
636      pcre_exec.c             )
637      pcre_fullinfo.c         )
638      pcre_get.c              ) sources for the functions in the library,
639      pcre_globals.c          )   and some internal functions that they use
640      pcre_info.c             )
641      pcre_maketables.c       )
642      pcre_newline.c          )
643      pcre_ord2utf8.c         )
644      pcre_refcount.c         )
645      pcre_study.c            )
646      pcre_tables.c           )
647      pcre_try_flipped.c      )
648      pcre_ucd.c              )
649      pcre_valid_utf8.c       )
650      pcre_version.c          )
651      pcre_xclass.c           )
652      pcre_printint.src       ) debugging function that is #included in pcretest,
653                              )   and can also be #included in pcre_compile()
654      pcre.h.in               template for pcre.h when built by "configure"
655      pcreposix.h             header for the external POSIX wrapper API
656      pcre_internal.h         header for internal use
657      ucp.h                   header for Unicode property handling
658    
659      config.h.in             template for config.h, which is built by "configure"
660    
661      pcrecpp.h               public header file for the C++ wrapper
662      pcrecpparg.h.in         template for another C++ header file
663      pcre_scanner.h          public header file for C++ scanner functions
664      pcrecpp.cc              )
665      pcre_scanner.cc         ) source for the C++ wrapper library
666    
667      pcre_stringpiece.h.in   template for pcre_stringpiece.h, the header for the
668                                C++ stringpiece functions
669      pcre_stringpiece.cc     source for the C++ stringpiece functions
670    
671    (B) Source files for programs that use PCRE:
672    
673      pcredemo.c              simple demonstration of coding calls to PCRE
674      pcregrep.c              source of a grep utility that uses PCRE
675      pcretest.c              comprehensive test program
676    
677    (C) Auxiliary files:
678    
679      132html                 script to turn "man" pages into HTML
680      AUTHORS                 information about the author of PCRE
681      ChangeLog               log of changes to the code
682      CleanTxt                script to clean nroff output for txt man pages
683      Detrail                 script to remove trailing spaces
684      HACKING                 some notes about the internals of PCRE
685      INSTALL                 generic installation instructions
686      LICENCE                 conditions for the use of PCRE
687      COPYING                 the same, using GNU's standard name
688      Makefile.in             ) template for Unix Makefile, which is built by
689                              )   "configure"
690      Makefile.am             ) the automake input that was used to create
691                              )   Makefile.in
692      NEWS                    important changes in this release
693      NON-UNIX-USE            notes on building PCRE on non-Unix systems
694      PrepareRelease          script to make preparations for "make dist"
695      README                  this file
696      RunTest                 a Unix shell script for running tests
697      RunGrepTest             a Unix shell script for pcregrep tests
698      aclocal.m4              m4 macros (generated by "aclocal")
699      config.guess            ) files used by libtool,
700      config.sub              )   used only when building a shared library
701      configure               a configuring shell script (built by autoconf)
702      configure.ac            ) the autoconf input that was used to build
703                              )   "configure" and config.h
704      depcomp                 ) script to find program dependencies, generated by
705                              )   automake
706      doc/*.3                 man page sources for the PCRE functions
707      doc/*.1                 man page sources for pcregrep and pcretest
708      doc/index.html.src      the base HTML page
709      doc/html/*              HTML documentation
710      doc/pcre.txt            plain text version of the man pages
711      doc/pcretest.txt        plain text documentation of test program
712      doc/perltest.txt        plain text documentation of Perl test program
713      install-sh              a shell script for installing files
714      libpcre.pc.in           template for libpcre.pc for pkg-config
715      libpcrecpp.pc.in        template for libpcrecpp.pc for pkg-config
716      ltmain.sh               file used to build a libtool script
717      missing                 ) common stub for a few missing GNU programs while
718                              )   installing, generated by automake
719      mkinstalldirs           script for making install directories
720      perltest.pl             Perl test program
721      pcre-config.in          source of script which retains PCRE information
722      pcrecpp_unittest.cc          )
723      pcre_scanner_unittest.cc     ) test programs for the C++ wrapper
724      pcre_stringpiece_unittest.cc )
725      testdata/testinput*     test data for main library tests
726      testdata/testoutput*    expected test results
727      testdata/grep*          input and output for pcregrep tests
728    
729    (D) Auxiliary files for cmake support
730    
731      cmake/COPYING-CMAKE-SCRIPTS
732      cmake/FindPackageHandleStandardArgs.cmake
733      cmake/FindReadline.cmake
734      CMakeLists.txt
735      config-cmake.h.in
736    
737    (E) Auxiliary files for VPASCAL
738    
739      makevp.bat
740      makevp_c.txt
741      makevp_l.txt
742      pcregexp.pas
743    
744    (F) Auxiliary files for building PCRE "by hand"
745    
746      pcre.h.generic          ) a version of the public PCRE header file
747                              )   for use in non-"configure" environments
748      config.h.generic        ) a version of config.h for use in non-"configure"
749                              )   environments
750    
751    (F) Miscellaneous
752    
753      RunTest.bat            a script for running tests under Windows
754    
755    Philip Hazel
756    Email local part: ph10
757    Email domain: cam.ac.uk
758    Last updated: 27 February 2009

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