/[pcre]/code/trunk/README
ViewVC logotype

Diff of /code/trunk/README

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 31 by nigel, Sat Feb 24 21:38:57 2007 UTC revision 122 by ph10, Mon Mar 12 15:10:25 2007 UTC
# Line 1  Line 1 
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 from
 *           IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00           *  
 *                                                                             *  
 * 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.                                *  
 *                                                                             *  
 *           IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.00                   *  
 *                                                                             *  
 * Another (I hope this is the last!) change has been made to the API for the  *  
 * pcre_compile() function. An additional argument has been added to make it   *  
 * possible to pass over a pointer to character tables built in the current    *  
 * locale by pcre_maketables(). To use the default tables, this new arguement  *  
 * should be passed as NULL.                                                   *  
 *******************************************************************************  
5    
6  The distribution should contain the following files:    ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-xxx.tar.gz
7    
8    ChangeLog         log of changes to the code  There is a mailing list for discussion about the development of PCRE at
9    LICENCE           conditions for the use of PCRE  
10    Makefile          for building PCRE    pcre-dev@exim.org
11    README            this file  
12    RunTest           a shell script for running tests  Please read the NEWS file if you are upgrading from a previous release.
13    Tech.Notes        notes on the encoding  The contents of this README file are:
14    pcre.3            man page for the functions  
15    pcreposix.3       man page for the POSIX wrapper API    The PCRE APIs
16    dftables.c        auxiliary program for building chartables.c    Documentation for PCRE
17    get.c             )    Contributions by users of PCRE
18    maketables.c      )    Building PCRE on non-Unix systems
19    study.c           ) source of    Building PCRE on Unix-like systems
20    pcre.c            )   the functions    Retrieving configuration information on Unix-like systems
21    pcreposix.c       )    Shared libraries on Unix-like systems
22    pcre.h            header for the external API    Cross-compiling on Unix-like systems
23    pcreposix.h       header for the external POSIX wrapper API    Using HP's ANSI C++ compiler (aCC)
24    internal.h        header for internal use    Making new tarballs
25    pcretest.c        test program    Testing PCRE
26    pgrep.1           man page for pgrep    Character tables
27    pgrep.c           source of a grep utility that uses PCRE    File manifest
28    perltest          Perl test program  
29    testinput         test data, compatible with Perl 5.004 and 5.005  
30    testinput2        test data for error messages and non-Perl things  The PCRE APIs
31    testinput3        test data, compatible with Perl 5.005  -------------
32    testinput4        test data for locale-specific tests  
33    testoutput        test results corresponding to testinput  PCRE is written in C, and it has its own API. The distribution now includes a
34    testoutput2       test results corresponding to testinput2  set of C++ wrapper functions, courtesy of Google Inc. (see the pcrecpp man page
35    testoutput3       test results corresponding to testinput3  for details).
36    testoutput4       test results corresponding to testinput4  
37    Also included in the distribution are a set of C wrapper functions that are
38  To build PCRE, edit Makefile for your system (it is a fairly simple make file,  based on the POSIX API. These end up in the library called libpcreposix. Note
39  and there are some comments at the top) and then run it. It builds two  that this just provides a POSIX calling interface to PCRE; the regular
40  libraries called libpcre.a and libpcreposix.a, a test program called pcretest,  expressions themselves still follow Perl syntax and semantics. The POSIX API is
41  and the pgrep command.  restricted, and does not give full access to all of PCRE's facilities.
42    
43  To test PCRE, run the RunTest script in the pcre directory. This runs pcretest  The header file for the POSIX-style functions is called pcreposix.h. The
44  on each of the testinput files in turn, and compares the output with the  official POSIX name is regex.h, but I did not want to risk possible problems
45  contents of the corresponding testoutput file. A file called testtry is used to  with existing files of that name by distributing it that way. To use PCRE with
46  hold the output from pcretest (which is documented below).  an existing program that uses the POSIX API, pcreposix.h will have to be
47    renamed or pointed at by a link.
48  To run pcretest on just one of the test files, give its number as an argument  
49  to RunTest, for example:  If you are using the POSIX interface to PCRE and there is already a POSIX regex
50    library installed on your system, as well as worrying about the regex.h header
51    RunTest 3  file (as mentioned above), you must also take care when linking programs to
52    ensure that they link with PCRE's libpcreposix library. Otherwise they may pick
53  The first and third test files can also be fed directly into the perltest  up the POSIX functions of the same name from the other library.
54  program to check that Perl gives the same results. The third file requires the  
55  additional features of release 5.005, which is why it is kept separate from the  One way of avoiding this confusion is to compile PCRE with the addition of
56  main test input, which needs only Perl 5.004. In the long run, when 5.005 is  -Dregcomp=PCREregcomp (and similarly for the other POSIX functions) to the
57  widespread, these two test files may get amalgamated.  compiler flags (CFLAGS if you are using "configure" -- see below). This has the
58    effect of renaming the functions so that the names no longer clash. Of course,
59  The second set of tests check pcre_info(), pcre_study(), pcre_copy_substring(),  you have to do the same thing for your applications, or write them using the
60  pcre_get_substring(), pcre_get_substring_list(), error detection and run-time  new names.
61  flags that are specific to PCRE, as well as the POSIX wrapper API.  
62    
63    Documentation for PCRE
64    ----------------------
65    
66    If you install PCRE in the normal way on a Unix-like system, you will end up
67    with a set of man pages whose names all start with "pcre". The one that is just
68    called "pcre" lists all the others. In addition to these man pages, the PCRE
69    documentation is supplied in two other forms:
70    
71      1. There are files called doc/pcre.txt, doc/pcregrep.txt, and
72         doc/pcretest.txt in the source distribution. The first of these is a
73         concatenation of the text forms of all the section 3 man pages except
74         those that summarize individual functions. The other two are the text
75         forms of the section 1 man pages for the pcregrep and pcretest commands.
76         These text forms are provided for ease of scanning with text editors or
77         similar tools. They are installed in <prefix>/share/doc/pcre, where
78         <prefix> is the installation prefix (defaulting to /usr/local).
79    
80      2. A set of files containing all the documentation in HTML form, hyperlinked
81         in various ways, and rooted in a file called index.html, is distributed in
82         doc/html and installed in <prefix>/share/doc/pcre/html.
83    
84    
85    Contributions by users of PCRE
86    ------------------------------
87    
88    You can find contributions from PCRE users in the directory
89    
90      ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/Contrib
91    
92    There is a README file giving brief descriptions of what they are. Some are
93    complete in themselves; others are pointers to URLs containing relevant files.
94    Some of this material is likely to be well out-of-date. In particular, several
95    of the contributions provide support for compiling PCRE on various flavours of
96    Windows (I myself do not use Windows), but nowadays there is more Windows
97    support in the standard distribution.
98    
99    
100    Building PCRE on non-Unix systems
101    ---------------------------------
102    
103    For a non-Unix system, please read the comments in the file NON-UNIX-USE,
104    though if your system supports the use of "configure" and "make" you may be
105    able to build PCRE in the same way as for Unix-like systems.
106    
107    PCRE has been compiled on many different operating systems. It should be
108    straightforward to build PCRE on any system that has a Standard C compiler and
109    library, because it uses only Standard C functions.
110    
111    
112    Building PCRE on Unix-like systems
113    ----------------------------------
114    
115    If you are using HP's ANSI C++ compiler (aCC), please see the special note
116    in the section entitled "Using HP's ANSI C++ compiler (aCC)" below.
117    
118    To build PCRE on a Unix-like system, first run the "configure" command from the
119    PCRE distribution directory, with your current directory set to the directory
120    where you want the files to be created. This command is a standard GNU
121    "autoconf" configuration script, for which generic instructions are supplied in
122    the file INSTALL.
123    
124    Most commonly, people build PCRE within its own distribution directory, and in
125    this case, on many systems, just running "./configure" is sufficient. However,
126    the usual methods of changing standard defaults are available. For example:
127    
128    CFLAGS='-O2 -Wall' ./configure --prefix=/opt/local
129    
130    specifies that the C compiler should be run with the flags '-O2 -Wall' instead
131    of the default, and that "make install" should install PCRE under /opt/local
132    instead of the default /usr/local.
133    
134    If you want to build in a different directory, just run "configure" with that
135    directory as current. For example, suppose you have unpacked the PCRE source
136    into /source/pcre/pcre-xxx, but you want to build it in /build/pcre/pcre-xxx:
137    
138    cd /build/pcre/pcre-xxx
139    /source/pcre/pcre-xxx/configure
140    
141    PCRE is written in C and is normally compiled as a C library. However, it is
142    possible to build it as a C++ library, though the provided building apparatus
143    does not have any features to support this.
144    
145    There are some optional features that can be included or omitted from the PCRE
146    library. You can read more about them in the pcrebuild man page.
147    
148    . If you want to suppress the building of the C++ wrapper library, you can add
149      --disable-cpp to the "configure" command. Otherwise, when "configure" is run,
150      will try to find a C++ compiler and C++ header files, and if it succeeds, it
151      will try to build the C++ wrapper.
152    
153    . If you want to make use of the support for UTF-8 character strings in PCRE,
154      you must add --enable-utf8 to the "configure" command. Without it, the code
155      for handling UTF-8 is not included in the library. (Even when included, it
156      still has to be enabled by an option at run time.)
157    
158    . If, in addition to support for UTF-8 character strings, you want to include
159      support for the \P, \p, and \X sequences that recognize Unicode character
160      properties, you must add --enable-unicode-properties to the "configure"
161      command. This adds about 30K to the size of the library (in the form of a
162      property table); only the basic two-letter properties such as Lu are
163      supported.
164    
165    . You can build PCRE to recognize either CR or LF or the sequence CRLF or any
166      of the Unicode newline sequences as indicating the end of a line. Whatever
167      you specify at build time is the default; the caller of PCRE can change the
168      selection at run time. The default newline indicator is a single LF character
169      (the Unix standard). You can specify the default newline indicator by adding
170      --newline-is-cr or --newline-is-lf or --newline-is-crlf or --newline-is-any
171      to the "configure" command, respectively.
172    
173      If you specify --newline-is-cr or --newline-is-crlf, some of the standard
174      tests will fail, because the lines in the test files end with LF. Even if
175      the files are edited to change the line endings, there are likely to be some
176      failures. With --newline-is-any, many tests should succeed, but there may be
177      some failures.
178    
179    . When called via the POSIX interface, PCRE uses malloc() to get additional
180      storage for processing capturing parentheses if there are more than 10 of
181      them. You can increase this threshold by setting, for example,
182    
183      --with-posix-malloc-threshold=20
184    
185      on the "configure" command.
186    
187    . PCRE has a counter that can be set to limit the amount of resources it uses.
188      If the limit is exceeded during a match, the match fails. The default is ten
189      million. You can change the default by setting, for example,
190    
191      --with-match-limit=500000
192    
193      on the "configure" command. This is just the default; individual calls to
194      pcre_exec() can supply their own value. There is more discussion on the
195      pcreapi man page.
196    
197    . There is a separate counter that limits the depth of recursive function calls
198      during a matching process. This also has a default of ten million, which is
199      essentially "unlimited". You can change the default by setting, for example,
200    
201      --with-match-limit-recursion=500000
202    
203      Recursive function calls use up the runtime stack; running out of stack can
204      cause programs to crash in strange ways. There is a discussion about stack
205      sizes in the pcrestack man page.
206    
207    . The default maximum compiled pattern size is around 64K. You can increase
208      this by adding --with-link-size=3 to the "configure" command. You can
209      increase it even more by setting --with-link-size=4, but this is unlikely
210      ever to be necessary.
211    
212    . You can build PCRE so that its internal match() function that is called from
213      pcre_exec() does not call itself recursively. Instead, it uses memory blocks
214      obtained from the heap via the special functions pcre_stack_malloc() and
215      pcre_stack_free() to save data that would otherwise be saved on the stack. To
216      build PCRE like this, use
217    
218      --disable-stack-for-recursion
219    
220      on the "configure" command. PCRE runs more slowly in this mode, but it may be
221      necessary in environments with limited stack sizes. This applies only to the
222      pcre_exec() function; it does not apply to pcre_dfa_exec(), which does not
223      use deeply nested recursion. There is a discussion about stack sizes in the
224      pcrestack man page.
225    
226    The "configure" script builds the following files for the basic C library:
227    
228    . Makefile is the makefile that builds the library
229    . config.h contains build-time configuration options for the library
230    . pcre.h is the public PCRE header file
231    . pcre-config is a script that shows the settings of "configure" options
232    . libpcre.pc is data for the pkg-config command
233    . libtool is a script that builds shared and/or static libraries
234    . RunTest is a script for running tests on the basic C library
235    . RunGrepTest is a script for running tests on the pcregrep command
236    
237    Versions of config.h and pcre.h are distributed in the PCRE tarballs under
238    the names config.h.generic and pcre.h.generic. These are provided for the
239    benefit of those who have to built PCRE without the benefit of "configure". If
240    you use "configure", the .generic versions are not used.
241    
242    If a C++ compiler is found, the following files are also built:
243    
244    . libpcrecpp.pc is data for the pkg-config command
245    . pcrecpparg.h is a header file for programs that call PCRE via the C++ wrapper
246    . pcre_stringpiece.h is the header for the C++ "stringpiece" functions
247    
248    The "configure" script also creates config.status, which is an executable
249    script that can be run to recreate the configuration, and config.log, which
250    contains compiler output from tests that "configure" runs.
251    
252    Once "configure" has run, you can run "make". It builds two libraries, called
253    libpcre and libpcreposix, a test program called pcretest, a demonstration
254    program called pcredemo, and the pcregrep command. If a C++ compiler was found
255    on your system, "make" also builds the C++ wrapper library, which is called
256    libpcrecpp, and some test programs called pcrecpp_unittest,
257    pcre_scanner_unittest, and pcre_stringpiece_unittest. Building the C++ wrapper
258    can be disabled by adding --disable-cpp to the "configure" command.
259    
260    The command "make check" runs all the appropriate tests. Details of the PCRE
261    tests are given below in a separate section of this document.
262    
263    You can use "make install" to install PCRE into live directories on your
264    system. The following are installed (file names are all relative to the
265    <prefix> that is set when "configure" is run):
266    
267      Commands (bin):
268        pcretest
269        pcregrep
270        pcre-config
271    
272      Libraries (lib):
273        libpcre
274        libpcreposix
275        libpcrecpp (if C++ support is enabled)
276    
277      Configuration information (lib/pkgconfig):
278        libpcre.pc
279        libpcrecpp.pc (if C++ support is enabled)
280    
281      Header files (include):
282        pcre.h
283        pcreposix.h
284        pcre_scanner.h      )
285        pcre_stringpiece.h  ) if C++ support is enabled
286        pcrecpp.h           )
287        pcrecpparg.h        )
288    
289      Man pages (share/man/man{1,3}):
290        pcregrep.1
291        pcretest.1
292        pcre.3
293        pcre*.3 (lots more pages, all starting "pcre")
294    
295      HTML documentation (share/doc/pcre/html):
296        index.html
297        *.html (lots more pages, hyperlinked from index.html)
298    
299      Text file documentation (share/doc/pcre):
300        AUTHORS
301        COPYING
302        ChangeLog
303        LICENCE
304        NEWS
305        README
306        pcre.txt       (a concatenation of the man(3) pages)
307        pcretest.txt   the pcretest man page
308        pcregrep.txt   the pcregrep man page
309    
310    Note that the pcredemo program that is built by "configure" is *not* installed
311    anywhere. It is a demonstration for programmers wanting to use PCRE.
312    
313    If you want to remove PCRE from your system, you can run "make uninstall".
314    This removes all the files that "make install" installed. However, it does not
315    remove any directories, because these are often shared with other programs.
316    
317    
318    Retrieving configuration information on Unix-like systems
319    ---------------------------------------------------------
320    
321    Running "make install" installs the command pcre-config, which can be used to
322    recall information about the PCRE configuration and installation. For example:
323    
324      pcre-config --version
325    
326    prints the version number, and
327    
328      pcre-config --libs
329    
330    outputs information about where the library is installed. This command can be
331    included in makefiles for programs that use PCRE, saving the programmer from
332    having to remember too many details.
333    
334    The pkg-config command is another system for saving and retrieving information
335    about installed libraries. Instead of separate commands for each library, a
336    single command is used. For example:
337    
338      pkg-config --cflags pcre
339    
340    The data is held in *.pc files that are installed in a directory called
341    <prefix>/lib/pkgconfig.
342    
343    
344    Shared libraries on Unix-like systems
345    -------------------------------------
346    
347    The default distribution builds PCRE as shared libraries and static libraries,
348    as long as the operating system supports shared libraries. Shared library
349    support relies on the "libtool" script which is built as part of the
350    "configure" process.
351    
352    The libtool script is used to compile and link both shared and static
353    libraries. They are placed in a subdirectory called .libs when they are newly
354    built. The programs pcretest and pcregrep are built to use these uninstalled
355    libraries (by means of wrapper scripts in the case of shared libraries). When
356    you use "make install" to install shared libraries, pcregrep and pcretest are
357    automatically re-built to use the newly installed shared libraries before being
358    installed themselves. However, the versions left in the build directory still
359    use the uninstalled libraries.
360    
361    To build PCRE using static libraries only you must use --disable-shared when
362    configuring it. For example:
363    
364    ./configure --prefix=/usr/gnu --disable-shared
365    
366    Then run "make" in the usual way. Similarly, you can use --disable-static to
367    build only shared libraries.
368    
369    
370    Cross-compiling on Unix-like systems
371    ------------------------------------
372    
373    You can specify CC and CFLAGS in the normal way to the "configure" command, in
374    order to cross-compile PCRE for some other host. However, during the building
375    process, the dftables.c source file is compiled *and run* on the local host, in
376    order to generate the default character tables (the chartables.c file). It
377    therefore needs to be compiled with the local compiler, not the cross compiler.
378    You can do this by specifying CC_FOR_BUILD (and if necessary CFLAGS_FOR_BUILD;
379    there are also CXX_FOR_BUILD and CXXFLAGS_FOR_BUILD for the C++ wrapper)
380    when calling the "configure" command. If they are not specified, they default
381    to the values of CC and CFLAGS.
382    
383    
384    Using HP's ANSI C++ compiler (aCC)
385    ----------------------------------
386    
387    Unless C++ support is disabled by specifying the "--disable-cpp" option of the
388    "configure" script, you must include the "-AA" option in the CXXFLAGS
389    environment variable in order for the C++ components to compile correctly.
390    
391    Also, note that the aCC compiler on PA-RISC platforms may have a defect whereby
392    needed libraries fail to get included when specifying the "-AA" compiler
393    option. If you experience unresolved symbols when linking the C++ programs,
394    use the workaround of specifying the following environment variable prior to
395    running the "configure" script:
396    
397      CXXLDFLAGS="-lstd_v2 -lCsup_v2"
398    
399    
400    Making new tarballs
401    -------------------
402    
403    The command "make dist" creates three PCRE tarballs, in tar.gz, tar.bz2, and
404    zip formats. However, if you have modified any of the man page sources in the
405    doc directory, you should first run the PrepareRelease script. This re-creates
406    the .txt and HTML forms of the documentation from the man pages.
407    
408    
409    Testing PCRE
410    ------------
411    
412    To test the basic PCRE library on a Unix system, run the RunTest script that is
413    created by the configuring process. There is also a script called RunGrepTest
414    that tests the options of the pcregrep command. If the C++ wrapper library is
415    built, three test programs called pcrecpp_unittest, pcre_scanner_unittest, and
416    pcre_stringpiece_unittest are also built.
417    
418    Both the scripts and all the program tests are run if you obey "make check" or
419    "make test". For other systems, see the instructions in NON-UNIX-USE.
420    
421    The RunTest script runs the pcretest test program (which is documented in its
422    own man page) on each of the testinput files in the testdata directory in
423    turn, and compares the output with the contents of the corresponding testoutput
424    files. A file called testtry is used to hold the main output from pcretest
425    (testsavedregex is also used as a working file). To run pcretest on just one of
426    the test files, give its number as an argument to RunTest, for example:
427    
428      RunTest 2
429    
430    The first test file can also be fed directly into the perltest.pl script to
431    check that Perl gives the same results. The only difference you should see is
432    in the first few lines, where the Perl version is given instead of the PCRE
433    version.
434    
435    The second set of tests check pcre_fullinfo(), pcre_info(), pcre_study(),
436    pcre_copy_substring(), pcre_get_substring(), pcre_get_substring_list(), error
437    detection, and run-time flags that are specific to PCRE, as well as the POSIX
438    wrapper API. It also uses the debugging flags to check some of the internals of
439    pcre_compile().
440    
441    If you build PCRE with a locale setting that is not the standard C locale, the
442    character tables may be different (see next paragraph). In some cases, this may
443    cause failures in the second set of tests. For example, in a locale where the
444    isprint() function yields TRUE for characters in the range 128-255, the use of
445    [:isascii:] inside a character class defines a different set of characters, and
446    this shows up in this test as a difference in the compiled code, which is being
447    listed for checking. Where the comparison test output contains [\x00-\x7f] the
448    test will contain [\x00-\xff], and similarly in some other cases. This is not a
449    bug in PCRE.
450    
451  The fourth set of tests checks pcre_maketables(), the facility for building a  The third set of tests checks pcre_maketables(), the facility for building a
452  set of character tables for a specific locale and using them instead of the  set of character tables for a specific locale and using them instead of the
453  default tables. The tests make use of the "fr" (French) locale. Before running  default tables. The tests make use of the "fr_FR" (French) locale. Before
454  the test, the script checks for the presence of this locale by running the  running the test, the script checks for the presence of this locale by running
455  "locale" command. If that command fails, or if it doesn't include "fr" in the  the "locale" command. If that command fails, or if it doesn't include "fr_FR"
456  list of available locales, the fourth test cannot be run, and a comment is  in the list of available locales, the third test cannot be run, and a comment
457  output to say why. If running this test produces instances of the error  is output to say why. If running this test produces instances of the error
458    
459    ** Failed to set locale "fr"    ** Failed to set locale "fr_FR"
460    
461  in the comparison output, it means that locale is not available on your system,  in the comparison output, it means that locale is not available on your system,
462  despite being listed by "locale". This does not mean that PCRE is broken.  despite being listed by "locale". This does not mean that PCRE is broken.
463    
464  To install PCRE, copy libpcre.a to any suitable library directory (e.g.  The fourth test checks the UTF-8 support. It is not run automatically unless
465  /usr/local/lib), pcre.h to any suitable include directory (e.g.  PCRE is built with UTF-8 support. To do this you must set --enable-utf8 when
466  /usr/local/include), and pcre.3 to any suitable man directory (e.g.  running "configure". This file can be also fed directly to the perltest script,
467  /usr/local/man/man3).  provided you are running Perl 5.8 or higher. (For Perl 5.6, a small patch,
468    commented in the script, can be be used.)
469  To install the pgrep command, copy it to any suitable binary directory, (e.g.  
470  /usr/local/bin) and pgrep.1 to any suitable man directory (e.g.  The fifth test checks error handling with UTF-8 encoding, and internal UTF-8
471  /usr/local/man/man1).  features of PCRE that are not relevant to Perl.
472    
473  PCRE has its own native API, but a set of "wrapper" functions that are based on  The sixth test checks the support for Unicode character properties. It it not
474  the POSIX API are also supplied in the library libpcreposix.a. Note that this  run automatically unless PCRE is built with Unicode property support. To to
475  just provides a POSIX calling interface to PCRE: the regular expressions  this you must set --enable-unicode-properties when running "configure".
476  themselves still follow Perl syntax and semantics. The header file  
477  for the POSIX-style functions is called pcreposix.h. The official POSIX name is  The seventh, eighth, and ninth tests check the pcre_dfa_exec() alternative
478  regex.h, but I didn't want to risk possible problems with existing files of  matching function, in non-UTF-8 mode, UTF-8 mode, and UTF-8 mode with Unicode
479  that name by distributing it that way. To use it with an existing program that  property support, respectively. The eighth and ninth tests are not run
480  uses the POSIX API, it will have to be renamed or pointed at by a link.  automatically unless PCRE is build with the relevant support.
481    
482    
483  Character tables  Character tables
484  ----------------  ----------------
485    
486  PCRE uses four tables for manipulating and identifying characters. The final  For speed, PCRE uses four tables for manipulating and identifying characters
487  argument of the pcre_compile() function is a pointer to a block of memory  whose code point values are less than 256. The final argument of the
488  containing the concatenated tables. A call to pcre_maketables() is used to  pcre_compile() function is a pointer to a block of memory containing the
489  generate a set of tables in the current locale. However, if the final argument  concatenated tables. A call to pcre_maketables() can be used to generate a set
490  is passed as NULL, a set of default tables that is built into the binary is  of tables in the current locale. If the final argument for pcre_compile() is
491  used.  passed as NULL, a set of default tables that is built into the binary is used.
492    
493  The source file called chartables.c contains the default set of tables. This is  The source file called chartables.c contains the default set of tables. This is
494  not supplied in the distribution, but is built by the program dftables  not supplied in the distribution, but is built by the program dftables
495  (compiled from dftables.c), which uses the ANSI C character handling functions  (compiled from dftables.c), which uses the ANSI C character handling functions
496  such as isalnum(), isalpha(), isupper(), islower(), etc. to build the table  such as isalnum(), isalpha(), isupper(), islower(), etc. to build the table
497  sources. This means that the default C locale set your system will control the  sources. This means that the default C locale which is set for your system will
498  contents of the tables. You can change the default tables by editing  control the contents of these default tables. You can change the default tables
499  chartables.c and then re-building PCRE. If you do this, you should probably  by editing chartables.c and then re-building PCRE. If you do this, you should
500  also edit Makefile to ensure that the file doesn't ever get re-generated.  take care to ensure that the file does not get automaticaly re-generated.
501    
502  The first two 256-byte tables provide lower casing and case flipping functions,  The first two 256-byte tables provide lower casing and case flipping functions,
503  respectively. The next table consists of three 32-byte bit maps which identify  respectively. The next table consists of three 32-byte bit maps which identify
504  digits, "word" characters, and white space, respectively. These are used when  digits, "word" characters, and white space, respectively. These are used when
505  building 32-byte bit maps that represent character classes.  building 32-byte bit maps that represent character classes for code points less
506    than 256.
507    
508  The final 256-byte table has bits indicating various character types, as  The final 256-byte table has bits indicating various character types, as
509  follows:  follows:
# Line 145  You should not alter the set of characte Line 519  You should not alter the set of characte
519  will cause PCRE to malfunction.  will cause PCRE to malfunction.
520    
521    
522  The pcretest program  File manifest
523  --------------------  -------------
524    
525    The distribution should contain the following files:
526    
527  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.  
528    
529  If it is given two filename arguments, it reads from the first and writes to    dftables.c             auxiliary program for building chartables.c
 the second. If it is given only one filename argument, it reads from that file  
 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 other than backslash, for example  
   
   /(a|bc)x+yz/  
   
 White space before the initial delimiter is ignored. A regular expression may  
 be continued over several input lines, in which case the newline characters are  
 included within it. See the testinput files for many examples. It is possible  
 to include the delimiter within the pattern by escaping it, for example  
   
   /abc\/def/  
   
 If you do so, the escape and the delimiter form part of the pattern, but since  
 delimiters are always non-alphameric, this does not affect its interpretation.  
 If the terminating delimiter is immediately followed by a backslash, for  
 example,  
   
   /abc/\  
   
 then a backslash is added to the end of the pattern. This provides a way of  
 testing the error condition that arises if a pattern finishes with a backslash,  
 because  
   
   /abc\/  
   
 is interpreted as the first line of a pattern that starts with "abc/", causing  
 pcretest to read the next line as a continuation of the regular expression.  
   
 The pattern 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 /L option must be followed directly by the name of a locale, for example,  
   
   /pattern/Lfr  
   
 For this reason, it must be the last option letter. The given locale is set,  
 pcre_maketables() is called to build a set of character tables for the locale,  
 and this is then passed to pcre_compile() when compiling the regular  
 expression. Without an /L option, NULL is passed as the tables pointer; that  
 is, /L applies only to the expression on which it appears.  
   
 The /I option requests that pcretest output information about the compiled  
 expression (whether it is anchored, has a fixed first character, and so on). It  
 does this by calling pcre_info() after compiling an expression, and outputting  
 the information it gets back. If the pattern is studied, the results of that  
 are also output.  
   
 The /D option is a PCRE debugging feature, which also assumes /I. 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.  
   
 The /M option causes information about the size of memory block used to hold  
 the compile pattern to be output.  
   
 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.  
   
 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()  
   \Cdd   call pcre_copy_substring() for substring dd after a successful match  
            (any decimal number less than 32)  
   \Gdd   call pcre_get_substring() for substring dd after a successful match  
            (any decimal number less than 32)  
   \L     call pcre_get_substringlist() after a successful match  
   \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 captured 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  
   
 If any of \C, \G, or \L are present in a data line that is successfully  
 matched, the substrings extracted by the convenience functions are output with  
 C, G, or L after the string number instead of a colon. This is in addition to  
 the normal full list. The string length (that is, the return from the  
 extraction function) is given in parentheses after each string for \C and \G.  
   
 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 is given to pcretest, it is equivalent to adding /I to each  
 regular expression: information about the compiled pattern is given after  
 compilation.  
   
 If the option -m is given to pcretest, it outputs the size of each compiled  
 pattern after it has been compiled. It is equivalent to adding /M to each  
 regular expression. For compatibility with earlier versions of pcretest, -s is  
 a synonym for -m.  
   
 If the -t option is given, each compile, study, and match is run 20000 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  
 20000 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 and testinput4 files are not suitable for feeding to Perltest,  
 since they do make use of the special upper case options and escapes that  
 pcretest uses to test some features of PCRE. The first of these files also  
 contains malformed regular expressions, in order to check that PCRE diagnoses  
 them correctly.  
530    
531  Philip Hazel <ph10@cam.ac.uk>    pcreposix.c            )
532  February 1999    pcre_compile.c         )
533      pcre_config.c          )
534      pcre_dfa_exec.c        )
535      pcre_exec.c            )
536      pcre_fullinfo.c        )
537      pcre_get.c             ) sources for the functions in the library,
538      pcre_globals.c         )   and some internal functions that they use
539      pcre_info.c            )
540      pcre_maketables.c      )
541      pcre_newline.c         )
542      pcre_ord2utf8.c        )
543      pcre_refcount.c        )
544      pcre_study.c           )
545      pcre_tables.c          )
546      pcre_try_flipped.c     )
547      pcre_ucp_searchfuncs.c )
548      pcre_valid_utf8.c      )
549      pcre_version.c         )
550      pcre_xclass.c          )
551      pcre_printint.src      ) debugging function that is #included in pcretest,
552                             )   and can also be #included in pcre_compile()
553      pcre.h.in              template for pcre.h when built by "configure"
554      pcreposix.h            header for the external POSIX wrapper API
555      pcre_internal.h        header for internal use
556      ucp.h                  ) headers concerned with
557      ucpinternal.h          )   Unicode property handling
558      ucptable.h             ) (this one is the data table)
559    
560      config.h.in            template for config.h, which is built by "configure"
561    
562      pcrecpp.h              public header file for the C++ wrapper
563      pcrecpparg.h.in        template for another C++ header file
564      pcre_scanner.h         public header file for C++ scanner functions
565      pcrecpp.cc             )
566      pcre_scanner.cc        ) source for the C++ wrapper library
567    
568      pcre_stringpiece.h.in  template for pcre_stringpiece.h, the header for the
569                               C++ stringpiece functions
570      pcre_stringpiece.cc    source for the C++ stringpiece functions
571    
572    (B) Source files for programs that use PCRE:
573    
574      pcredemo.c             simple demonstration of coding calls to PCRE
575      pcregrep.c             source of a grep utility that uses PCRE
576      pcretest.c             comprehensive test program
577    
578    (C) Auxiliary files:
579    
580      132html                script to turn "man" pages into HTML
581      AUTHORS                information about the author of PCRE
582      ChangeLog              log of changes to the code
583      CleanTxt               script to clean nroff output for txt man pages
584      Detrail                script to remove trailing spaces
585      Index.html             the base HTML page
586      INSTALL                generic installation instructions
587      LICENCE                conditions for the use of PCRE
588      COPYING                the same, using GNU's standard name
589      Makefile.in            ) template for Unix Makefile, which is built by
590                             )   "configure"
591      Makefile.am            ) the automake input that was used to create
592                             )   Makefile.in
593      NEWS                   important changes in this release
594      NON-UNIX-USE           notes on building PCRE on non-Unix systems
595      PrepareRelease         script to make preparations for "make dist"
596      README                 this file
597      RunTest.in             template for a Unix shell script for running tests
598      RunGrepTest.in         template for a Unix shell script for pcregrep tests
599      aclocal.m4             m4 macros (generated by "aclocal")
600      config.guess           ) files used by libtool,
601      config.sub             )   used only when building a shared library
602      configure              a configuring shell script (built by autoconf)
603      configure.ac           ) the autoconf input that was used to build
604                             )   "configure" and config.h
605      depcomp                ) script to find program dependencies, generated by
606                             )   automake
607      doc/*.3                man page sources for the PCRE functions
608      doc/*.1                man page sources for pcregrep and pcretest
609      doc/html/*             HTML documentation
610      doc/pcre.txt           plain text version of the man pages
611      doc/pcretest.txt       plain text documentation of test program
612      doc/perltest.txt       plain text documentation of Perl test program
613      install-sh             a shell script for installing files
614      libpcre.pc.in          template for libpcre.pc for pkg-config
615      libpcrecpp.pc.in       template for libpcrecpp.pc for pkg-config
616      ltmain.sh              file used to build a libtool script
617      missing                ) common stub for a few missing GNU programs while
618                             )   installing, generated by automake
619      mkinstalldirs          script for making install directories
620      perltest.pl            Perl test program
621      pcre-config.in         source of script which retains PCRE information
622      pcrecpp_unittest.cc          )
623      pcre_scanner_unittest.cc     ) test programs for the C++ wrapper
624      pcre_stringpiece_unittest.cc )
625      testdata/testinput*    test data for main library tests
626      testdata/testoutput*   expected test results
627      testdata/grep*         input and output for pcregrep tests
628    
629    (D) Auxiliary files for cmake support
630    
631      CMakeLists.txt
632      config-cmake.h.in
633    
634    (E) Auxiliary files for VPASCAL
635    
636      makevp.bat
637      !compile.txt
638      !linklib.txt
639      pcregexp.pas
640    
641    (F) Auxiliary files for building PCRE "by hand"
642    
643      pcre.h.generic         ) a version of the public PCRE header file
644                             )   for use in non-"configure" environments
645      config.h.generic       ) a version of config.h for use in non-"configure"
646                             )   environments
647    
648    (F) Miscellaneous
649    
650      RunTest.bat            a script for running tests under Windows
651    
652    Philip Hazel
653    Email local part: ph10
654    Email domain: cam.ac.uk
655    Last updated: March 2007
Legend:
Removed from v.31  
changed lines
  Added in v.122
  ViewVC Help
Powered by ViewVC 1.1.5