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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 distribution should contain the following files:  The latest release of PCRE is always available in three alternative formats
5    from:
6    
7    ChangeLog         log of changes to the code    ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-xxx.tar.gz
8    Makefile          for building PCRE    ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-xxx.tar.bz2
9    Performance       notes on performance    ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-xxx.zip
10    README            this file  
11    Tech.Notes        notes on the encoding  There is a mailing list for discussion about the development of PCRE at
12    pcre.3            man page for the functions  
13    pcreposix.3       man page for the POSIX wrapper API    pcre-dev@exim.org
14    maketables.c      auxiliary program for building chartables.c  
15    study.c           ) source of  Please read the NEWS file if you are upgrading from a previous release.
16    pcre.c            )   the functions  The contents of this README file are:
17    pcreposix.c       )  
18    pcre.h            header for the external API    The PCRE APIs
19    pcreposix.h       header for the external POSIX wrapper API    Documentation for PCRE
20    internal.h        header for internal use    Contributions by users of PCRE
21    pcretest.c        test program    Building PCRE on non-Unix systems
22    pgrep.1           man page for pgrep    Building PCRE on Unix-like systems
23    pgrep.c           source of a grep utility that uses PCRE    Retrieving configuration information on Unix-like systems
24    perltest          Perl test program    Shared libraries on Unix-like systems
25    testinput         test data, compatible with Perl    Cross-compiling on Unix-like systems
26    testinput2        test data for error messages and non-Perl things    Using HP's ANSI C++ compiler (aCC)
27    testoutput        test results corresponding to testinput    Using PCRE from MySQL
28    testoutput2       test results corresponding to testinput2    Making new tarballs
29      Testing PCRE
30  To build PCRE, edit Makefile for your system (it is a fairly simple make file)    Character tables
31  and then run it. It builds a two libraries called libpcre.a and libpcreposix.a,    File manifest
32  a test program called pcretest, and the pgrep command.  
33    
34  To test PCRE, run pcretest on the file testinput, and compare the output with  The PCRE APIs
35  the contents of testoutput. There should be no differences. For example:  -------------
36    
37    pcretest testinput /tmp/anything  PCRE is written in C, and it has its own API. There are two sets of functions,
38    diff /tmp/anything testoutput  one for the 8-bit library, which processes strings of bytes, and one for the
39    16-bit library, which processes strings of 16-bit values. The distribution also
40  Do the same with testinput2, comparing the output with testoutput2, but this  includes a set of C++ wrapper functions (see the pcrecpp man page for details),
41  time using the -i flag for pcretest, i.e.  courtesy of Google Inc., which can be used to call the 8-bit PCRE library from
42    C++.
43    pcretest -i testinput2 /tmp/anything  
44    diff /tmp/anything testoutput2  In addition, there is a set of C wrapper functions (again, just for the 8-bit
45    library) that are based on the POSIX regular expression API (see the pcreposix
46  There are two sets of tests because the first set can also be fed directly into  man page). These end up in the library called libpcreposix. Note that this just
47  the perltest program to check that Perl gives the same results. The second set  provides a POSIX calling interface to PCRE; the regular expressions themselves
48  of tests check pcre_info(), pcre_study(), error detection and run-time flags  still follow Perl syntax and semantics. The POSIX API is restricted, and does
49  that are specific to PCRE, as well as the POSIX wrapper API.  not give full access to all of PCRE's facilities.
50    
51  To install PCRE, copy libpcre.a to any suitable library directory (e.g.  The header file for the POSIX-style functions is called pcreposix.h. The
52  /usr/local/lib), pcre.h to any suitable include directory (e.g.  official POSIX name is regex.h, but I did not want to risk possible problems
53  /usr/local/include), and pcre.3 to any suitable man directory (e.g.  with existing files of that name by distributing it that way. To use PCRE with
54  /usr/local/man/man3).  an existing program that uses the POSIX API, pcreposix.h will have to be
55    renamed or pointed at by a link.
56  To install the pgrep command, copy it to any suitable binary directory, (e.g.  
57  /usr/local/bin) and pgrep.1 to any suitable man directory (e.g.  If you are using the POSIX interface to PCRE and there is already a POSIX regex
58  /usr/local/man/man1).  library installed on your system, as well as worrying about the regex.h header
59    file (as mentioned above), you must also take care when linking programs to
60  PCRE has its own native API, but a set of "wrapper" functions that are based on  ensure that they link with PCRE's libpcreposix library. Otherwise they may pick
61  the POSIX API are also supplied in the library libpcreposix.a. Note that this  up the POSIX functions of the same name from the other library.
62  just provides a POSIX calling interface to PCRE: the regular expressions  
63  themselves still follow Perl syntax and semantics. The header file  One way of avoiding this confusion is to compile PCRE with the addition of
64  for the POSIX-style functions is called pcreposix.h. The official POSIX name is  -Dregcomp=PCREregcomp (and similarly for the other POSIX functions) to the
65  regex.h, but I didn't want to risk possible problems with existing files of  compiler flags (CFLAGS if you are using "configure" -- see below). This has the
66  that name by distributing it that way. To use it with an existing program that  effect of renaming the functions so that the names no longer clash. Of course,
67  uses the POSIX API it will have to be renamed or pointed at by a link.  you have to do the same thing for your applications, or write them using the
68    new names.
69    
70    
71    Documentation for PCRE
72    ----------------------
73    
74    If you install PCRE in the normal way on a Unix-like system, you will end up
75    with a set of man pages whose names all start with "pcre". The one that is just
76    called "pcre" lists all the others. In addition to these man pages, the PCRE
77    documentation is supplied in two other forms:
78    
79      1. There are files called doc/pcre.txt, doc/pcregrep.txt, and
80         doc/pcretest.txt in the source distribution. The first of these is a
81         concatenation of the text forms of all the section 3 man pages except
82         those that summarize individual functions. The other two are the text
83         forms of the section 1 man pages for the pcregrep and pcretest commands.
84         These text forms are provided for ease of scanning with text editors or
85         similar tools. They are installed in <prefix>/share/doc/pcre, where
86         <prefix> is the installation prefix (defaulting to /usr/local).
87    
88      2. A set of files containing all the documentation in HTML form, hyperlinked
89         in various ways, and rooted in a file called index.html, is distributed in
90         doc/html and installed in <prefix>/share/doc/pcre/html.
91    
92    Users of PCRE have contributed files containing the documentation for various
93    releases in CHM format. These can be found in the Contrib directory of the FTP
94    site (see next section).
95    
96    
97    Contributions by users of PCRE
98    ------------------------------
99    
100    You can find contributions from PCRE users in the directory
101    
102      ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/Contrib
103    
104    There is a README file giving brief descriptions of what they are. Some are
105    complete in themselves; others are pointers to URLs containing relevant files.
106    Some of this material is likely to be well out-of-date. Several of the earlier
107    contributions provided support for compiling PCRE on various flavours of
108    Windows (I myself do not use Windows). Nowadays there is more Windows support
109    in the standard distribution, so these contibutions have been archived.
110    
111    
112    Building PCRE on non-Unix systems
113    ---------------------------------
114    
115    For a non-Unix system, please read the comments in the file NON-UNIX-USE,
116    though if your system supports the use of "configure" and "make" you may be
117    able to build PCRE in the same way as for Unix-like systems. PCRE can also be
118    configured in many platform environments using the GUI facility provided by
119    CMake's cmake-gui command. This creates Makefiles, solution files, etc.
120    
121    PCRE has been compiled on many different operating systems. It should be
122    straightforward to build PCRE on any system that has a Standard C compiler and
123    library, because it uses only Standard C functions.
124    
125    
126    Building PCRE on Unix-like systems
127    ----------------------------------
128    
129    If you are using HP's ANSI C++ compiler (aCC), please see the special note
130    in the section entitled "Using HP's ANSI C++ compiler (aCC)" below.
131    
132    The following instructions assume the use of the widely used "configure, make,
133    make install" process. There is also support for CMake in the PCRE
134    distribution; there are some comments about using CMake in the NON-UNIX-USE
135    file, though it can also be used in Unix-like systems.
136    
137    To build PCRE on a Unix-like system, first run the "configure" command from the
138    PCRE distribution directory, with your current directory set to the directory
139    where you want the files to be created. This command is a standard GNU
140    "autoconf" configuration script, for which generic instructions are supplied in
141    the file INSTALL.
142    
143    Most commonly, people build PCRE within its own distribution directory, and in
144    this case, on many systems, just running "./configure" is sufficient. However,
145    the usual methods of changing standard defaults are available. For example:
146    
147    CFLAGS='-O2 -Wall' ./configure --prefix=/opt/local
148    
149    This command specifies that the C compiler should be run with the flags '-O2
150    -Wall' instead of the default, and that "make install" should install PCRE
151    under /opt/local instead of the default /usr/local.
152    
153    If you want to build in a different directory, just run "configure" with that
154    directory as current. For example, suppose you have unpacked the PCRE source
155    into /source/pcre/pcre-xxx, but you want to build it in /build/pcre/pcre-xxx:
156    
157    cd /build/pcre/pcre-xxx
158    /source/pcre/pcre-xxx/configure
159    
160    PCRE is written in C and is normally compiled as a C library. However, it is
161    possible to build it as a C++ library, though the provided building apparatus
162    does not have any features to support this.
163    
164    There are some optional features that can be included or omitted from the PCRE
165    library. They are also documented in the pcrebuild man page.
166    
167    . By default, both shared and static libraries are built. You can change this
168      by adding one of these options to the "configure" command:
169    
170      --disable-shared
171      --disable-static
172    
173      (See also "Shared libraries on Unix-like systems" below.)
174    
175    . By default, only the 8-bit library is built. If you add --enable-pcre16 to
176      the "configure" command, the 16-bit library is also built. If you want only
177      the 16-bit library, use "./configure --enable-pcre16 --disable-pcre8".
178    
179    . If you are building the 8-bit library and want to suppress the building of
180      the C++ wrapper library, you can add --disable-cpp to the "configure"
181      command. Otherwise, when "configure" is run without --disable-pcre8, it will
182      try to find a C++ compiler and C++ header files, and if it succeeds, it will
183      try to build the C++ wrapper.
184    
185    . If you want to include support for just-in-time compiling, which can give
186      large performance improvements on certain platforms, add --enable-jit to the
187      "configure" command. This support is available only for certain hardware
188      architectures. If you try to enable it on an unsupported architecture, there
189      will be a compile time error.
190    
191    . When JIT support is enabled, pcregrep automatically makes use of it, unless
192      you add --disable-pcregrep-jit to the "configure" command.
193    
194    . If you want to make use of the support for UTF-8 Unicode character strings in
195      the 8-bit library, or UTF-16 Unicode character strings in the 16-bit library,
196      you must add --enable-utf to the "configure" command. Without it, the code
197      for handling UTF-8 and UTF-16 is not included in the relevant library. Even
198      when --enable-utf is included, the use of a UTF encoding still has to be
199      enabled by an option at run time. When PCRE is compiled with this option, its
200      input can only either be ASCII or UTF-8/16, even when running on EBCDIC
201      platforms. It is not possible to use both --enable-utf and --enable-ebcdic at
202      the same time.
203    
204    . There are no separate options for enabling UTF-8 and UTF-16 independently
205      because that would allow ridiculous settings such as requesting UTF-16
206      support while building only the 8-bit library. However, the option
207      --enable-utf8 is retained for backwards compatibility with earlier releases
208      that did not support 16-bit character strings. It is synonymous with
209      --enable-utf. It is not possible to configure one library with UTF support
210      and the other without in the same configuration.
211    
212    . If, in addition to support for UTF-8/16 character strings, you want to
213      include support for the \P, \p, and \X sequences that recognize Unicode
214      character properties, you must add --enable-unicode-properties to the
215      "configure" command. This adds about 30K to the size of the library (in the
216      form of a property table); only the basic two-letter properties such as Lu
217      are supported.
218    
219    . You can build PCRE to recognize either CR or LF or the sequence CRLF or any
220      of the preceding, or any of the Unicode newline sequences as indicating the
221      end of a line. Whatever you specify at build time is the default; the caller
222      of PCRE can change the selection at run time. The default newline indicator
223      is a single LF character (the Unix standard). You can specify the default
224      newline indicator by adding --enable-newline-is-cr or --enable-newline-is-lf
225      or --enable-newline-is-crlf or --enable-newline-is-anycrlf or
226      --enable-newline-is-any to the "configure" command, respectively.
227    
228      If you specify --enable-newline-is-cr or --enable-newline-is-crlf, some of
229      the standard tests will fail, because the lines in the test files end with
230      LF. Even if the files are edited to change the line endings, there are likely
231      to be some failures. With --enable-newline-is-anycrlf or
232      --enable-newline-is-any, many tests should succeed, but there may be some
233      failures.
234    
235    . By default, the sequence \R in a pattern matches any Unicode line ending
236      sequence. This is independent of the option specifying what PCRE considers to
237      be the end of a line (see above). However, the caller of PCRE can restrict \R
238      to match only CR, LF, or CRLF. You can make this the default by adding
239      --enable-bsr-anycrlf to the "configure" command (bsr = "backslash R").
240    
241    . When called via the POSIX interface, PCRE uses malloc() to get additional
242      storage for processing capturing parentheses if there are more than 10 of
243      them in a pattern. You can increase this threshold by setting, for example,
244    
245      --with-posix-malloc-threshold=20
246    
247      on the "configure" command.
248    
249    . PCRE has a counter that can be set to limit the amount of resources it uses.
250      If the limit is exceeded during a match, the match fails. The default is ten
251      million. You can change the default by setting, for example,
252    
253      --with-match-limit=500000
254    
255      on the "configure" command. This is just the default; individual calls to
256      pcre_exec() can supply their own value. There is more discussion on the
257      pcreapi man page.
258    
259    . There is a separate counter that limits the depth of recursive function calls
260      during a matching process. This also has a default of ten million, which is
261      essentially "unlimited". You can change the default by setting, for example,
262    
263      --with-match-limit-recursion=500000
264    
265      Recursive function calls use up the runtime stack; running out of stack can
266      cause programs to crash in strange ways. There is a discussion about stack
267      sizes in the pcrestack man page.
268    
269    . The default maximum compiled pattern size is around 64K. You can increase
270      this by adding --with-link-size=3 to the "configure" command. In the 8-bit
271      library, PCRE then uses three bytes instead of two for offsets to different
272      parts of the compiled pattern. In the 16-bit library, --with-link-size=3 is
273      the same as --with-link-size=4, which (in both libraries) uses four-byte
274      offsets. Increasing the internal link size reduces performance.
275    
276    . You can build PCRE so that its internal match() function that is called from
277      pcre_exec() does not call itself recursively. Instead, it uses memory blocks
278      obtained from the heap via the special functions pcre_stack_malloc() and
279      pcre_stack_free() to save data that would otherwise be saved on the stack. To
280      build PCRE like this, use
281    
282      --disable-stack-for-recursion
283    
284      on the "configure" command. PCRE runs more slowly in this mode, but it may be
285      necessary in environments with limited stack sizes. This applies only to the
286      normal execution of the pcre_exec() function; if JIT support is being
287      successfully used, it is not relevant. Equally, it does not apply to
288      pcre_dfa_exec(), which does not use deeply nested recursion. There is a
289      discussion about stack sizes in the pcrestack man page.
290    
291    . For speed, PCRE uses four tables for manipulating and identifying characters
292      whose code point values are less than 256. By default, it uses a set of
293      tables for ASCII encoding that is part of the distribution. If you specify
294    
295      --enable-rebuild-chartables
296    
297      a program called dftables is compiled and run in the default C locale when
298      you obey "make". It builds a source file called pcre_chartables.c. If you do
299      not specify this option, pcre_chartables.c is created as a copy of
300      pcre_chartables.c.dist. See "Character tables" below for further information.
301    
302    . It is possible to compile PCRE for use on systems that use EBCDIC as their
303      character code (as opposed to ASCII) by specifying
304    
305      --enable-ebcdic
306    
307      This automatically implies --enable-rebuild-chartables (see above). However,
308      when PCRE is built this way, it always operates in EBCDIC. It cannot support
309      both EBCDIC and UTF-8/16.
310    
311    . The pcregrep program currently supports only 8-bit data files, and so
312      requires the 8-bit PCRE library. It is possible to compile pcregrep to use
313      libz and/or libbz2, in order to read .gz and .bz2 files (respectively), by
314      specifying one or both of
315    
316      --enable-pcregrep-libz
317      --enable-pcregrep-libbz2
318    
319      Of course, the relevant libraries must be installed on your system.
320    
321    . The default size of internal buffer used by pcregrep can be set by, for
322      example:
323    
324      --with-pcregrep-bufsize=50K
325    
326      The default value is 20K.
327    
328    . It is possible to compile pcretest so that it links with the libreadline
329      library, by specifying
330    
331      --enable-pcretest-libreadline
332    
333      If this is done, when pcretest's input is from a terminal, it reads it using
334      the readline() function. This provides line-editing and history facilities.
335      Note that libreadline is GPL-licenced, so if you distribute a binary of
336      pcretest linked in this way, there may be licensing issues.
337    
338      Setting this option causes the -lreadline option to be added to the pcretest
339      build. In many operating environments with a sytem-installed readline
340      library this is sufficient. However, in some environments (e.g. if an
341      unmodified distribution version of readline is in use), it may be necessary
342      to specify something like LIBS="-lncurses" as well. This is because, to quote
343      the readline INSTALL, "Readline uses the termcap functions, but does not link
344      with the termcap or curses library itself, allowing applications which link
345      with readline the to choose an appropriate library." If you get error
346      messages about missing functions tgetstr, tgetent, tputs, tgetflag, or tgoto,
347      this is the problem, and linking with the ncurses library should fix it.
348    
349    The "configure" script builds the following files for the basic C library:
350    
351    . Makefile             the makefile that builds the library
352    . config.h             build-time configuration options for the library
353    . pcre.h               the public PCRE header file
354    . pcre-config          script that shows the building settings such as CFLAGS
355                             that were set for "configure"
356    . libpcre.pc         ) data for the pkg-config command
357    . libpcre16.pc       )
358    . libpcreposix.pc    )
359    . libtool              script that builds shared and/or static libraries
360    . RunTest              script for running tests on the basic C library
361    . RunGrepTest          script for running tests on the pcregrep command
362    
363    Versions of config.h and pcre.h are distributed in the PCRE tarballs under the
364    names config.h.generic and pcre.h.generic. These are provided for those who
365    have to built PCRE without using "configure" or CMake. If you use "configure"
366    or CMake, the .generic versions are not used.
367    
368    When building the 8-bit library, if a C++ compiler is found, the following
369    files are also built:
370    
371    . libpcrecpp.pc        data for the pkg-config command
372    . pcrecpparg.h         header file for calling PCRE via the C++ wrapper
373    . pcre_stringpiece.h   header for the C++ "stringpiece" functions
374    
375    The "configure" script also creates config.status, which is an executable
376    script that can be run to recreate the configuration, and config.log, which
377    contains compiler output from tests that "configure" runs.
378    
379    Once "configure" has run, you can run "make". This builds either or both of the
380    libraries libpcre and libpcre16, and a test program called pcretest. If you
381    enabled JIT support with --enable-jit, a test program called pcre_jit_test is
382    built as well.
383    
384    If the 8-bit library is built, libpcreposix and the pcregrep command are also
385    built, and if a C++ compiler was found on your system, and you did not disable
386    it with --disable-cpp, "make" builds the C++ wrapper library, which is called
387    libpcrecpp, as well as some test programs called pcrecpp_unittest,
388    pcre_scanner_unittest, and pcre_stringpiece_unittest.
389    
390    The command "make check" runs all the appropriate tests. Details of the PCRE
391    tests are given below in a separate section of this document.
392    
393    You can use "make install" to install PCRE into live directories on your
394    system. The following are installed (file names are all relative to the
395    <prefix> that is set when "configure" is run):
396    
397      Commands (bin):
398        pcretest
399        pcregrep (if 8-bit support is enabled)
400        pcre-config
401    
402      Libraries (lib):
403        libpcre16     (if 16-bit support is enabled)
404        libpcre       (if 8-bit support is enabled)
405        libpcreposix  (if 8-bit support is enabled)
406        libpcrecpp    (if 8-bit and C++ support is enabled)
407    
408      Configuration information (lib/pkgconfig):
409        libpcre16.pc
410        libpcre.pc
411        libpcreposix.pc
412        libpcrecpp.pc (if C++ support is enabled)
413    
414      Header files (include):
415        pcre.h
416        pcreposix.h
417        pcre_scanner.h      )
418        pcre_stringpiece.h  ) if C++ support is enabled
419        pcrecpp.h           )
420        pcrecpparg.h        )
421    
422      Man pages (share/man/man{1,3}):
423        pcregrep.1
424        pcretest.1
425        pcre-config.1
426        pcre.3
427        pcre*.3 (lots more pages, all starting "pcre")
428    
429      HTML documentation (share/doc/pcre/html):
430        index.html
431        *.html (lots more pages, hyperlinked from index.html)
432    
433      Text file documentation (share/doc/pcre):
434        AUTHORS
435        COPYING
436        ChangeLog
437        LICENCE
438        NEWS
439        README
440        pcre.txt         (a concatenation of the man(3) pages)
441        pcretest.txt     the pcretest man page
442        pcregrep.txt     the pcregrep man page
443        pcre-config.txt  the pcre-config man page
444    
445    If you want to remove PCRE from your system, you can run "make uninstall".
446    This removes all the files that "make install" installed. However, it does not
447    remove any directories, because these are often shared with other programs.
448    
449    
450    Retrieving configuration information on Unix-like systems
451    ---------------------------------------------------------
452    
453    Running "make install" installs the command pcre-config, which can be used to
454    recall information about the PCRE configuration and installation. For example:
455    
456      pcre-config --version
457    
458    prints the version number, and
459    
460      pcre-config --libs
461    
462    outputs information about where the library is installed. This command can be
463    included in makefiles for programs that use PCRE, saving the programmer from
464    having to remember too many details.
465    
466    The pkg-config command is another system for saving and retrieving information
467    about installed libraries. Instead of separate commands for each library, a
468    single command is used. For example:
469    
470      pkg-config --cflags pcre
471    
472    The data is held in *.pc files that are installed in a directory called
473    <prefix>/lib/pkgconfig.
474    
475    
476    Shared libraries on Unix-like systems
477    -------------------------------------
478    
479    The default distribution builds PCRE as shared libraries and static libraries,
480    as long as the operating system supports shared libraries. Shared library
481    support relies on the "libtool" script which is built as part of the
482    "configure" process.
483    
484    The libtool script is used to compile and link both shared and static
485    libraries. They are placed in a subdirectory called .libs when they are newly
486    built. The programs pcretest and pcregrep are built to use these uninstalled
487    libraries (by means of wrapper scripts in the case of shared libraries). When
488    you use "make install" to install shared libraries, pcregrep and pcretest are
489    automatically re-built to use the newly installed shared libraries before being
490    installed themselves. However, the versions left in the build directory still
491    use the uninstalled libraries.
492    
493    To build PCRE using static libraries only you must use --disable-shared when
494    configuring it. For example:
495    
496    ./configure --prefix=/usr/gnu --disable-shared
497    
498    Then run "make" in the usual way. Similarly, you can use --disable-static to
499    build only shared libraries.
500    
501    
502    Cross-compiling on Unix-like systems
503    ------------------------------------
504    
505    You can specify CC and CFLAGS in the normal way to the "configure" command, in
506    order to cross-compile PCRE for some other host. However, you should NOT
507    specify --enable-rebuild-chartables, because if you do, the dftables.c source
508    file is compiled and run on the local host, in order to generate the inbuilt
509    character tables (the pcre_chartables.c file). This will probably not work,
510    because dftables.c needs to be compiled with the local compiler, not the cross
511    compiler.
512    
513    When --enable-rebuild-chartables is not specified, pcre_chartables.c is created
514    by making a copy of pcre_chartables.c.dist, which is a default set of tables
515    that assumes ASCII code. Cross-compiling with the default tables should not be
516    a problem.
517    
518    If you need to modify the character tables when cross-compiling, you should
519    move pcre_chartables.c.dist out of the way, then compile dftables.c by hand and
520    run it on the local host to make a new version of pcre_chartables.c.dist.
521    Then when you cross-compile PCRE this new version of the tables will be used.
522    
523    
524    Using HP's ANSI C++ compiler (aCC)
525    ----------------------------------
526    
527    Unless C++ support is disabled by specifying the "--disable-cpp" option of the
528    "configure" script, you must include the "-AA" option in the CXXFLAGS
529    environment variable in order for the C++ components to compile correctly.
530    
531    Also, note that the aCC compiler on PA-RISC platforms may have a defect whereby
532    needed libraries fail to get included when specifying the "-AA" compiler
533    option. If you experience unresolved symbols when linking the C++ programs,
534    use the workaround of specifying the following environment variable prior to
535    running the "configure" script:
536    
537      CXXLDFLAGS="-lstd_v2 -lCsup_v2"
538    
539    
540    Using Sun's compilers for Solaris
541    ---------------------------------
542    
543    A user reports that the following configurations work on Solaris 9 sparcv9 and
544    Solaris 9 x86 (32-bit):
545    
546      Solaris 9 sparcv9: ./configure --disable-cpp CC=/bin/cc CFLAGS="-m64 -g"
547      Solaris 9 x86:     ./configure --disable-cpp CC=/bin/cc CFLAGS="-g"
548    
549    
550    Using PCRE from MySQL
551    ---------------------
552    
553    On systems where both PCRE and MySQL are installed, it is possible to make use
554    of PCRE from within MySQL, as an alternative to the built-in pattern matching.
555    There is a web page that tells you how to do this:
556    
557      http://www.mysqludf.org/lib_mysqludf_preg/index.php
558    
559    
560    Making new tarballs
561    -------------------
562    
563    The command "make dist" creates three PCRE tarballs, in tar.gz, tar.bz2, and
564    zip formats. The command "make distcheck" does the same, but then does a trial
565    build of the new distribution to ensure that it works.
566    
567    If you have modified any of the man page sources in the doc directory, you
568    should first run the PrepareRelease script before making a distribution. This
569    script creates the .txt and HTML forms of the documentation from the man pages.
570    
571    
572    Testing PCRE
573    ------------
574    
575    To test the basic PCRE library on a Unix system, run the RunTest script that is
576    created by the configuring process. There is also a script called RunGrepTest
577    that tests the options of the pcregrep command. If the C++ wrapper library is
578    built, three test programs called pcrecpp_unittest, pcre_scanner_unittest, and
579    pcre_stringpiece_unittest are also built. When JIT support is enabled, another
580    test program called pcre_jit_test is built.
581    
582    Both the scripts and all the program tests are run if you obey "make check" or
583    "make test". For other systems, see the instructions in NON-UNIX-USE.
584    
585    The RunTest script runs the pcretest test program (which is documented in its
586    own man page) on each of the relevant testinput files in the testdata
587    directory, and compares the output with the contents of the corresponding
588    testoutput files. Some tests are relevant only when certain build-time options
589    were selected. For example, the tests for UTF-8/16 support are run only if
590    --enable-utf was used. RunTest outputs a comment when it skips a test.
591    
592    Many of the tests that are not skipped are run up to three times. The second
593    run forces pcre_study() to be called for all patterns except for a few in some
594    tests that are marked "never study" (see the pcretest program for how this is
595    done). If JIT support is available, the non-DFA tests are run a third time,
596    this time with a forced pcre_study() with the PCRE_STUDY_JIT_COMPILE option.
597    
598    When both 8-bit and 16-bit support is enabled, the entire set of tests is run
599    twice, once for each library. If you want to run just one set of tests, call
600    RunTest with either the -8 or -16 option.
601    
602    RunTest uses a file called testtry to hold the main output from pcretest.
603    Other files whose names begin with "test" are used as working files in some
604    tests. To run pcretest on just one or more specific test files, give their
605    numbers as arguments to RunTest, for example:
606    
607      RunTest 2 7 11
608    
609    The first test file can be fed directly into the perltest.pl script to check
610    that Perl gives the same results. The only difference you should see is in the
611    first few lines, where the Perl version is given instead of the PCRE version.
612    
613    The second set of tests check pcre_fullinfo(), pcre_study(),
614    pcre_copy_substring(), pcre_get_substring(), pcre_get_substring_list(), error
615    detection, and run-time flags that are specific to PCRE, as well as the POSIX
616    wrapper API. It also uses the debugging flags to check some of the internals of
617    pcre_compile().
618    
619    If you build PCRE with a locale setting that is not the standard C locale, the
620    character tables may be different (see next paragraph). In some cases, this may
621    cause failures in the second set of tests. For example, in a locale where the
622    isprint() function yields TRUE for characters in the range 128-255, the use of
623    [:isascii:] inside a character class defines a different set of characters, and
624    this shows up in this test as a difference in the compiled code, which is being
625    listed for checking. Where the comparison test output contains [\x00-\x7f] the
626    test will contain [\x00-\xff], and similarly in some other cases. This is not a
627    bug in PCRE.
628    
629    The third set of tests checks pcre_maketables(), the facility for building a
630    set of character tables for a specific locale and using them instead of the
631    default tables. The tests make use of the "fr_FR" (French) locale. Before
632    running the test, the script checks for the presence of this locale by running
633    the "locale" command. If that command fails, or if it doesn't include "fr_FR"
634    in the list of available locales, the third test cannot be run, and a comment
635    is output to say why. If running this test produces instances of the error
636    
637      ** Failed to set locale "fr_FR"
638    
639    in the comparison output, it means that locale is not available on your system,
640    despite being listed by "locale". This does not mean that PCRE is broken.
641    
642    [If you are trying to run this test on Windows, you may be able to get it to
643    work by changing "fr_FR" to "french" everywhere it occurs. Alternatively, use
644    RunTest.bat. The version of RunTest.bat included with PCRE 7.4 and above uses
645    Windows versions of test 2. More info on using RunTest.bat is included in the
646    document entitled NON-UNIX-USE.]
647    
648    The fourth and fifth tests check the UTF-8/16 support and error handling and
649    internal UTF features of PCRE that are not relevant to Perl, respectively. The
650    sixth and seventh tests do the same for Unicode character properties support.
651    
652    The eighth, ninth, and tenth tests check the pcre_dfa_exec() alternative
653    matching function, in non-UTF-8/16 mode, UTF-8/16 mode, and UTF-8/16 mode with
654    Unicode property support, respectively.
655    
656    The eleventh test checks some internal offsets and code size features; it is
657    run only when the default "link size" of 2 is set (in other cases the sizes
658    change) and when Unicode property support is enabled.
659    
660    The twelfth test is run only when JIT support is available, and the thirteenth
661    test is run only when JIT support is not available. They test some JIT-specific
662    features such as information output from pcretest about JIT compilation.
663    
664    The fourteenth, fifteenth, and sixteenth tests are run only in 8-bit mode, and
665    the seventeenth, eighteenth, and nineteenth tests are run only in 16-bit mode.
666    These are tests that generate different output in the two modes. They are for
667    general cases, UTF-8/16 support, and Unicode property support, respectively.
668    
669    The twentieth test is run only in 16-bit mode. It tests some specific 16-bit
670    features of the DFA matching engine.
671    
672    The twenty-first and twenty-second tests are run only in 16-bit mode, when the
673    link size is set to 2. They test reloading pre-compiled patterns.
674    
675    
676  Character tables  Character tables
677  ----------------  ----------------
678    
679  PCRE uses four tables for manipulating and identifying characters. These are  For speed, PCRE uses four tables for manipulating and identifying characters
680  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
681  the distribution, but is built by the program maketables (compiled from  pcre_compile() function is a pointer to a block of memory containing the
682  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
683  isalnum(), isalpha(), isupper(), islower(), etc. to build the table sources.  of tables in the current locale. If the final argument for pcre_compile() is
684  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.
685  of the tables. You can change the tables by editing chartables.c and then  
686  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
687  ensure that the file doesn't ever get re-generated.  default, this is created as a copy of pcre_chartables.c.dist, which contains
688    tables for ASCII coding. However, if --enable-rebuild-chartables is specified
689  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
690  case flipping functions, respectively. The pcre_cbits[] table consists of four  program dftables (compiled from dftables.c), which uses the ANSI C character
691  32-byte bit maps which identify digits, letters, "word" characters, and white  handling functions such as isalnum(), isalpha(), isupper(), islower(), etc. to
692  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
693  represent character classes.  your system will control the contents of these default tables. You can change
694    the default tables by editing pcre_chartables.c and then re-building PCRE. If
695    you do this, you should take care to ensure that the file does not get
696    automatically re-generated. The best way to do this is to move
697    pcre_chartables.c.dist out of the way and replace it with your customized
698    tables.
699    
700    When the dftables program is run as a result of --enable-rebuild-chartables,
701    it uses the default C locale that is set on your system. It does not pay
702    attention to the LC_xxx environment variables. In other words, it uses the
703    system's default locale rather than whatever the compiling user happens to have
704    set. If you really do want to build a source set of character tables in a
705    locale that is specified by the LC_xxx variables, you can run the dftables
706    program by hand with the -L option. For example:
707    
708      ./dftables -L pcre_chartables.c.special
709    
710    The first two 256-byte tables provide lower casing and case flipping functions,
711    respectively. The next table consists of three 32-byte bit maps which identify
712    digits, "word" characters, and white space, respectively. These are used when
713    building 32-byte bit maps that represent character classes for code points less
714    than 256.
715    
716  The pcre_ctypes[] table has bits indicating various character types, as  The final 256-byte table has bits indicating various character types, as
717  follows:  follows:
718    
719      1   white space character      1   white space character
# Line 99  You should not alter the set of characte Line 727  You should not alter the set of characte
727  will cause PCRE to malfunction.  will cause PCRE to malfunction.
728    
729    
730  The pcretest program  File manifest
731  --------------------  -------------
   
 This program is intended for testing PCRE, but it can also be used for  
 experimenting with regular expressions.  
   
 If it is given two filename arguments, it reads from the first and writes to  
 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, 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. If /I is present as well as  
 /S, then pcre_study() is called with the PCRE_CASELESS option.  
   
 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 file 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()  
   \E     pass the PCRE_DOLLAR_ENDONLY option to pcre_exec()  
   \I     pass the PCRE_CASELESS option to pcre_exec()  
   \M     pass the PCRE_MULTILINE option to pcre_exec()  
   \S     pass the PCRE_DOTALL 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 2000 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  
 2000 times and the timing will be distorted.  
   
   
   
 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 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 additional features of PCRE.  
732    
733  Philip Hazel <ph10@cam.ac.uk>  The distribution should contain the files listed below. Where a file name is
734  October 1997  given as pcre[16]_xxx it means that there are two files, one with the name
735    pcre_xxx and the other with the name pcre16_xxx.
736    
737    (A) Source files of the PCRE library functions and their headers:
738    
739      dftables.c              auxiliary program for building pcre_chartables.c
740                                when --enable-rebuild-chartables is specified
741    
742      pcre_chartables.c.dist  a default set of character tables that assume ASCII
743                                coding; used, unless --enable-rebuild-chartables is
744                                specified, by copying to pcre[16]_chartables.c
745    
746      pcreposix.c             )
747      pcre[16]_byte_order.c   )
748      pcre[16]_compile.c      )
749      pcre[16]_config.c       )
750      pcre[16]_dfa_exec.c     )
751      pcre[16]_exec.c         )
752      pcre[16]_fullinfo.c     )
753      pcre[16]_get.c          ) sources for the functions in the library,
754      pcre[16]_globals.c      )   and some internal functions that they use
755      pcre[16]_jit_compile.c  )
756      pcre[16]_maketables.c   )
757      pcre[16]_newline.c      )
758      pcre[16]_refcount.c     )
759      pcre[16]_string_utils.c )
760      pcre[16]_study.c        )
761      pcre[16]_tables.c       )
762      pcre[16]_ucd.c          )
763      pcre[16]_version.c      )
764      pcre[16]_xclass.c       )
765      pcre_ord2utf8.c         )
766      pcre_valid_utf8.c       )
767      pcre16_ord2utf16.c      )
768      pcre16_utf16_utils.c    )
769      pcre16_valid_utf16.c    )
770    
771      pcre[16]_printint.c     ) debugging function that is used by pcretest,
772                              )   and can also be #included in pcre_compile()
773    
774      pcre.h.in               template for pcre.h when built by "configure"
775      pcreposix.h             header for the external POSIX wrapper API
776      pcre_internal.h         header for internal use
777      sljit/*                 16 files that make up the JIT compiler
778      ucp.h                   header for Unicode property handling
779    
780      config.h.in             template for config.h, which is built by "configure"
781    
782      pcrecpp.h               public header file for the C++ wrapper
783      pcrecpparg.h.in         template for another C++ header file
784      pcre_scanner.h          public header file for C++ scanner functions
785      pcrecpp.cc              )
786      pcre_scanner.cc         ) source for the C++ wrapper library
787    
788      pcre_stringpiece.h.in   template for pcre_stringpiece.h, the header for the
789                                C++ stringpiece functions
790      pcre_stringpiece.cc     source for the C++ stringpiece functions
791    
792    (B) Source files for programs that use PCRE:
793    
794      pcredemo.c              simple demonstration of coding calls to PCRE
795      pcregrep.c              source of a grep utility that uses PCRE
796      pcretest.c              comprehensive test program
797    
798    (C) Auxiliary files:
799    
800      132html                 script to turn "man" pages into HTML
801      AUTHORS                 information about the author of PCRE
802      ChangeLog               log of changes to the code
803      CleanTxt                script to clean nroff output for txt man pages
804      Detrail                 script to remove trailing spaces
805      HACKING                 some notes about the internals of PCRE
806      INSTALL                 generic installation instructions
807      LICENCE                 conditions for the use of PCRE
808      COPYING                 the same, using GNU's standard name
809      Makefile.in             ) template for Unix Makefile, which is built by
810                              )   "configure"
811      Makefile.am             ) the automake input that was used to create
812                              )   Makefile.in
813      NEWS                    important changes in this release
814      NON-UNIX-USE            notes on building PCRE on non-Unix systems
815      PrepareRelease          script to make preparations for "make dist"
816      README                  this file
817      RunTest                 a Unix shell script for running tests
818      RunGrepTest             a Unix shell script for pcregrep tests
819      aclocal.m4              m4 macros (generated by "aclocal")
820      config.guess            ) files used by libtool,
821      config.sub              )   used only when building a shared library
822      configure               a configuring shell script (built by autoconf)
823      configure.ac            ) the autoconf input that was used to build
824                              )   "configure" and config.h
825      depcomp                 ) script to find program dependencies, generated by
826                              )   automake
827      doc/*.3                 man page sources for PCRE
828      doc/*.1                 man page sources for pcregrep and pcretest
829      doc/index.html.src      the base HTML page
830      doc/html/*              HTML documentation
831      doc/pcre.txt            plain text version of the man pages
832      doc/pcretest.txt        plain text documentation of test program
833      doc/perltest.txt        plain text documentation of Perl test program
834      install-sh              a shell script for installing files
835      libpcre16.pc.in         template for libpcre16.pc for pkg-config
836      libpcre.pc.in           template for libpcre.pc for pkg-config
837      libpcreposix.pc.in      template for libpcreposix.pc for pkg-config
838      libpcrecpp.pc.in        template for libpcrecpp.pc for pkg-config
839      ltmain.sh               file used to build a libtool script
840      missing                 ) common stub for a few missing GNU programs while
841                              )   installing, generated by automake
842      mkinstalldirs           script for making install directories
843      perltest.pl             Perl test program
844      pcre-config.in          source of script which retains PCRE information
845      pcre_jit_test.c         test program for the JIT compiler
846      pcrecpp_unittest.cc          )
847      pcre_scanner_unittest.cc     ) test programs for the C++ wrapper
848      pcre_stringpiece_unittest.cc )
849      testdata/testinput*     test data for main library tests
850      testdata/testoutput*    expected test results
851      testdata/grep*          input and output for pcregrep tests
852      testdata/*              other supporting test files
853    
854    (D) Auxiliary files for cmake support
855    
856      cmake/COPYING-CMAKE-SCRIPTS
857      cmake/FindPackageHandleStandardArgs.cmake
858      cmake/FindReadline.cmake
859      CMakeLists.txt
860      config-cmake.h.in
861    
862    (E) Auxiliary files for VPASCAL
863    
864      makevp.bat
865      makevp_c.txt
866      makevp_l.txt
867      pcregexp.pas
868    
869    (F) Auxiliary files for building PCRE "by hand"
870    
871      pcre.h.generic          ) a version of the public PCRE header file
872                              )   for use in non-"configure" environments
873      config.h.generic        ) a version of config.h for use in non-"configure"
874                              )   environments
875    
876    (F) Miscellaneous
877    
878      RunTest.bat            a script for running tests under Windows
879    
880    Philip Hazel
881    Email local part: ph10
882    Email domain: cam.ac.uk
883    Last updated: 20 January 2012

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