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

Diff of /code/trunk/README

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

revision 41 by nigel, Sat Feb 24 21:39:17 2007 UTC revision 75 by nigel, Sat Feb 24 21:40:37 2007 UTC
# Line 1  Line 1 
1  README file for PCRE (Perl-compatible regular expression library)  README file for PCRE (Perl-compatible regular expression library)
2  -----------------------------------------------------------------  -----------------------------------------------------------------
3    
4    The latest release of PCRE is always available from
5    
6      ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-xxx.tar.gz
7    
8  Please read the NEWS file if you are upgrading from a previous release.  Please read the NEWS file if you are upgrading from a previous release.
9    
10    PCRE has its own native API, but a set of "wrapper" functions that are based on
11    the POSIX API are also supplied in the library libpcreposix. Note that this
12    just provides a POSIX calling interface to PCRE: the regular expressions
13    themselves still follow Perl syntax and semantics. The header file
14    for the POSIX-style functions is called pcreposix.h. The official POSIX name is
15    regex.h, but I didn't want to risk possible problems with existing files of
16    that name by distributing it that way. To use it with an existing program that
17    uses the POSIX API, it will have to be renamed or pointed at by a link.
18    
19    If you are using the POSIX interface to PCRE and there is already a POSIX regex
20    library installed on your system, you must take care when linking programs to
21    ensure that they link with PCRE's libpcreposix library. Otherwise they may pick
22    up the "real" POSIX functions of the same name.
23    
24    
25    Documentation for PCRE
26    ----------------------
27    
28    If you install PCRE in the normal way, you will end up with an installed set of
29    man pages whose names all start with "pcre". The one that is called "pcre"
30    lists all the others. In addition to these man pages, the PCRE documentation is
31    supplied in two other forms; however, as there is no standard place to install
32    them, they are left in the doc directory of the unpacked source distribution.
33    These forms are:
34    
35      1. Files called doc/pcre.txt, doc/pcregrep.txt, and doc/pcretest.txt. The
36         first of these is a concatenation of the text forms of all the section 3
37         man pages except those that summarize individual functions. The other two
38         are the text forms of the section 1 man pages for the pcregrep and
39         pcretest commands. Text forms are provided for ease of scanning with text
40         editors or similar tools.
41    
42      2. A subdirectory called doc/html contains all the documentation in HTML
43         form, hyperlinked in various ways, and rooted in a file called
44         doc/index.html.
45    
46  Building PCRE on a Unix system  
47    Contributions by users of PCRE
48  ------------------------------  ------------------------------
49    
50  To build PCRE on a Unix system, run the "configure" command in the PCRE  You can find contributions from PCRE users in the directory
51  distribution directory. This is a standard GNU "autoconf" configuration script,  
52  for which generic instructions are supplied in INSTALL. On many systems just    ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/Contrib
53  running "./configure" is sufficient, but the usual methods of changing standard  
54  defaults are available. For example  where there is also a README file giving brief descriptions of what they are.
55    Several of them provide support for compiling PCRE on various flavours of
56    Windows systems (I myself do not use Windows). Some are complete in themselves;
57    others are pointers to URLs containing relevant files.
58    
59    
60    Building PCRE on a Unix-like system
61    -----------------------------------
62    
63    To build PCRE on a Unix-like system, first run the "configure" command from the
64    PCRE distribution directory, with your current directory set to the directory
65    where you want the files to be created. This command is a standard GNU
66    "autoconf" configuration script, for which generic instructions are supplied in
67    INSTALL.
68    
69    Most commonly, people build PCRE within its own distribution directory, and in
70    this case, on many systems, just running "./configure" is sufficient, but the
71    usual methods of changing standard defaults are available. For example:
72    
73  CFLAGS='-O2 -Wall' ./configure --prefix=/opt/local  CFLAGS='-O2 -Wall' ./configure --prefix=/opt/local
74    
75  specifies that the C compiler should be run with the flags '-O2 -Wall' instead  specifies that the C compiler should be run with the flags '-O2 -Wall' instead
76  of the default, and that "make install" should install PCRE under /opt/local  of the default, and that "make install" should install PCRE under /opt/local
77  instead of the default /usr/local. The "configure" script builds two files:  instead of the default /usr/local.
78    
79  . Makefile is built by copying Makefile.in and making certain substitutions.  If you want to build in a different directory, just run "configure" with that
80  . config.h is built by copying config.in and making certain substitutions.  directory as current. For example, suppose you have unpacked the PCRE source
81    into /source/pcre/pcre-xxx, but you want to build it in /build/pcre/pcre-xxx:
82    
83    cd /build/pcre/pcre-xxx
84    /source/pcre/pcre-xxx/configure
85    
86    There are some optional features that can be included or omitted from the PCRE
87    library. You can read more about them in the pcrebuild man page.
88    
89    . If you want to make use of the support for UTF-8 character strings in PCRE,
90      you must add --enable-utf8 to the "configure" command. Without it, the code
91      for handling UTF-8 is not included in the library. (Even when included, it
92      still has to be enabled by an option at run time.)
93    
94    . If, in addition to support for UTF-8 character strings, you want to include
95      support for the \P, \p, and \X sequences that recognize Unicode character
96      properties, you must add --enable-unicode-properties to the "configure"
97      command. This adds about 90K to the size of the library (in the form of a
98      property table); only the basic two-letter properties such as Lu are
99      supported.
100    
101    . You can build PCRE to recognized CR or NL as the newline character, instead
102      of whatever your compiler uses for "\n", by adding --newline-is-cr or
103      --newline-is-nl to the "configure" command, respectively. Only do this if you
104      really understand what you are doing. On traditional Unix-like systems, the
105      newline character is NL.
106    
107    . When called via the POSIX interface, PCRE uses malloc() to get additional
108      storage for processing capturing parentheses if there are more than 10 of
109      them. You can increase this threshold by setting, for example,
110    
111      --with-posix-malloc-threshold=20
112    
113      on the "configure" command.
114    
115    . PCRE has a counter which can be set to limit the amount of resources it uses.
116      If the limit is exceeded during a match, the match fails. The default is ten
117      million. You can change the default by setting, for example,
118    
119      --with-match-limit=500000
120    
121      on the "configure" command. This is just the default; individual calls to
122      pcre_exec() can supply their own value. There is discussion on the pcreapi
123      man page.
124    
125    . The default maximum compiled pattern size is around 64K. You can increase
126      this by adding --with-link-size=3 to the "configure" command. You can
127      increase it even more by setting --with-link-size=4, but this is unlikely
128      ever to be necessary. If you build PCRE with an increased link size, test 2
129      (and 5 if you are using UTF-8) will fail. Part of the output of these tests
130      is a representation of the compiled pattern, and this changes with the link
131      size.
132    
133    . You can build PCRE so that its match() function does not call itself
134      recursively. Instead, it uses blocks of data from the heap via special
135      functions pcre_stack_malloc() and pcre_stack_free() to save data that would
136      otherwise be saved on the stack. To build PCRE like this, use
137    
138      --disable-stack-for-recursion
139    
140      on the "configure" command. PCRE runs more slowly in this mode, but it may be
141      necessary in environments with limited stack sizes.
142    
143    The "configure" script builds seven files:
144    
145    . pcre.h is build by copying pcre.in and making substitutions
146    . Makefile is built by copying Makefile.in and making substitutions.
147    . config.h is built by copying config.in and making substitutions.
148    . pcre-config is built by copying pcre-config.in and making substitutions.
149    . libpcre.pc is data for the pkg-config command, built from libpcre.pc.in
150    . libtool is a script that builds shared and/or static libraries
151    . RunTest is a script for running tests
152    
153  Once "configure" has run, you can run "make". It builds two libraries called  Once "configure" has run, you can run "make". It builds two libraries called
154  libpcre.a and libpcreposix.a, a test program called pcretest, and the pgrep  libpcre and libpcreposix, a test program called pcretest, and the pcregrep
155  command. You can use "make install" to copy these, and the public header file  command. You can use "make install" to copy these, the public header files
156  pcre.h, to appropriate live directories on your system, in the normal way.  pcre.h and pcreposix.h, and the man pages to appropriate live directories on
157    your system, in the normal way.
158    
159  Shared libraries on Unix systems  
160  --------------------------------  Retrieving configuration information on Unix-like systems
161    ---------------------------------------------------------
162  The default distribution builds static libraries. It is also possible to build  
163  PCRE as two shared libraries. This support is new and experimental and may not  Running "make install" also installs the command pcre-config, which can be used
164  work on all systems. It relies on the "libtool" scripts - these are distributed  to recall information about the PCRE configuration and installation. For
165  with PCRE. To build PCRE using shared libraries you must use --enable-shared  example:
166  when configuring it. For example  
167      pcre-config --version
168  ./configure --prefix=/usr/gnu --enable-shared  
169    prints the version number, and
170  Then run "make" in the usual way. It should build a "libtool" script and use  
171  this to compile and link shared libraries, which are placed in a subdirectory    pcre-config --libs
172  called .libs. The programs pcretest and pgrep are built to use these  
173  uninstalled libraries by means of wrapper scripts. When you use "make install"  outputs information about where the library is installed. This command can be
174  to install shared libraries, pgrep is automatically re-built to use the newly  included in makefiles for programs that use PCRE, saving the programmer from
175  installed library before it itself is installed.  having to remember too many details.
176    
177    The pkg-config command is another system for saving and retrieving information
178    about installed libraries. Instead of separate commands for each library, a
179    single command is used. For example:
180    
181      pkg-config --cflags pcre
182    
183    The data is held in *.pc files that are installed in a directory called
184    pkgconfig.
185    
186    
187    Shared libraries on Unix-like systems
188    -------------------------------------
189    
190    The default distribution builds PCRE as two shared libraries and two static
191    libraries, as long as the operating system supports shared libraries. Shared
192    library support relies on the "libtool" script which is built as part of the
193    "configure" process.
194    
195    The libtool script is used to compile and link both shared and static
196    libraries. They are placed in a subdirectory called .libs when they are newly
197    built. The programs pcretest and pcregrep are built to use these uninstalled
198    libraries (by means of wrapper scripts in the case of shared libraries). When
199    you use "make install" to install shared libraries, pcregrep and pcretest are
200    automatically re-built to use the newly installed shared libraries before being
201    installed themselves. However, the versions left in the source directory still
202    use the uninstalled libraries.
203    
204    To build PCRE using static libraries only you must use --disable-shared when
205    configuring it. For example:
206    
207    ./configure --prefix=/usr/gnu --disable-shared
208    
209    Then run "make" in the usual way. Similarly, you can use --disable-static to
210    build only shared libraries.
211    
212    
213    Cross-compiling on a Unix-like system
214    -------------------------------------
215    
216    You can specify CC and CFLAGS in the normal way to the "configure" command, in
217    order to cross-compile PCRE for some other host. However, during the building
218    process, the dftables.c source file is compiled *and run* on the local host, in
219    order to generate the default character tables (the chartables.c file). It
220    therefore needs to be compiled with the local compiler, not the cross compiler.
221    You can do this by specifying CC_FOR_BUILD (and if necessary CFLAGS_FOR_BUILD)
222    when calling the "configure" command. If they are not specified, they default
223    to the values of CC and CFLAGS.
224    
225    
226  Building on non-Unix systems  Building on non-Unix systems
227  ----------------------------  ----------------------------
228    
229  For a non-Unix system, read the comments in the file NON-UNIX-USE. PCRE has  For a non-Unix system, read the comments in the file NON-UNIX-USE, though if
230  been compiled on Windows systems and on Macintoshes, but I don't know the  the system supports the use of "configure" and "make" you may be able to build
231  details because I don't use those systems. It should be straightforward to  PCRE in the same way as for Unix systems.
232    
233    PCRE has been compiled on Windows systems and on Macintoshes, but I don't know
234    the details because I don't use those systems. It should be straightforward to
235  build PCRE on any system that has a Standard C compiler, because it uses only  build PCRE on any system that has a Standard C compiler, because it uses only
236  Standard C functions.  Standard C functions.
237    
# Line 60  Standard C functions. Line 239  Standard C functions.
239  Testing PCRE  Testing PCRE
240  ------------  ------------
241    
242  To test PCRE on a Unix system, run the RunTest script in the pcre directory.  To test PCRE on a Unix system, run the RunTest script that is created by the
243  (This can also be run by "make runtest" or "make check".) For other systems,  configuring process. (This can also be run by "make runtest", "make check", or
244  see the instruction in NON-UNIX-USE.  "make test".) For other systems, see the instructions in NON-UNIX-USE.
245    
246  The script runs the pcretest test program (which is documented in  The script runs the pcretest test program (which is documented in its own man
247  doc/pcretest.txt) on each of the testinput files (in the testdata directory) in  page) on each of the testinput files (in the testdata directory) in turn,
248  turn, and compares the output with the contents of the corresponding testoutput  and compares the output with the contents of the corresponding testoutput file.
249  file. A file called testtry is used to hold the output from pcretest. To run  A file called testtry is used to hold the main output from pcretest
250  pcretest on just one of the test files, give its number as an argument to  (testsavedregex is also used as a working file). To run pcretest on just one of
251  RunTest, for example:  the test files, give its number as an argument to RunTest, for example:
252    
253    RunTest 3    RunTest 2
254    
255  The first and third test files can also be fed directly into the perltest  The first file can also be fed directly into the perltest script to check that
256  script to check that Perl gives the same results. The third file requires the  Perl gives the same results. The only difference you should see is in the first
257  additional features of release 5.005, which is why it is kept separate from the  few lines, where the Perl version is given instead of the PCRE version.
258  main test input, which needs only Perl 5.004. In the long run, when 5.005 is  
259  widespread, these two test files may get amalgamated.  The second set of tests check pcre_fullinfo(), pcre_info(), pcre_study(),
260    pcre_copy_substring(), pcre_get_substring(), pcre_get_substring_list(), error
261  The second set of tests check pcre_info(), pcre_study(), pcre_copy_substring(),  detection, and run-time flags that are specific to PCRE, as well as the POSIX
262  pcre_get_substring(), pcre_get_substring_list(), error detection and run-time  wrapper API. It also uses the debugging flag to check some of the internals of
263  flags that are specific to PCRE, as well as the POSIX wrapper API.  pcre_compile().
264    
265    If you build PCRE with a locale setting that is not the standard C locale, the
266    character tables may be different (see next paragraph). In some cases, this may
267    cause failures in the second set of tests. For example, in a locale where the
268    isprint() function yields TRUE for characters in the range 128-255, the use of
269    [:isascii:] inside a character class defines a different set of characters, and
270    this shows up in this test as a difference in the compiled code, which is being
271    listed for checking. Where the comparison test output contains [\x00-\x7f] the
272    test will contain [\x00-\xff], and similarly in some other cases. This is not a
273    bug in PCRE.
274    
275  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
276  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
277  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
278  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
279  "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"
280  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
281  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
282    
283    ** Failed to set locale "fr"    ** Failed to set locale "fr_FR"
284    
285  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,
286  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.
287    
288  PCRE has its own native API, but a set of "wrapper" functions that are based on  The fourth test checks the UTF-8 support. It is not run automatically unless
289  the POSIX API are also supplied in the library libpcreposix.a. Note that this  PCRE is built with UTF-8 support. To do this you must set --enable-utf8 when
290  just provides a POSIX calling interface to PCRE: the regular expressions  running "configure". This file can be also fed directly to the perltest script,
291  themselves still follow Perl syntax and semantics. The header file  provided you are running Perl 5.8 or higher. (For Perl 5.6, a small patch,
292  for the POSIX-style functions is called pcreposix.h. The official POSIX name is  commented in the script, can be be used.)
293  regex.h, but I didn't want to risk possible problems with existing files of  
294  that name by distributing it that way. To use it with an existing program that  The fifth test checks error handling with UTF-8 encoding, and internal UTF-8
295  uses the POSIX API, it will have to be renamed or pointed at by a link.  features of PCRE that are not relevant to Perl.
296    
297    The sixth and final test checks the support for Unicode character properties.
298    It it not run automatically unless PCRE is built with Unicode property support.
299    To to this you must set --enable-unicode-properties when running "configure".
300    
301    
302  Character tables  Character tables
303  ----------------  ----------------
304    
305  PCRE uses four tables for manipulating and identifying characters. The final  PCRE uses four tables for manipulating and identifying characters whose values
306  argument of the pcre_compile() function is a pointer to a block of memory  are less than 256. The final argument of the pcre_compile() function is a
307  containing the concatenated tables. A call to pcre_maketables() can be used to  pointer to a block of memory containing the concatenated tables. A call to
308  generate a set of tables in the current locale. If the final argument for  pcre_maketables() can be used to generate a set of tables in the current
309  pcre_compile() is passed as NULL, a set of default tables that is built into  locale. If the final argument for pcre_compile() is passed as NULL, a set of
310  the binary is used.  default tables that is built into the binary is used.
311    
312  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
313  not supplied in the distribution, but is built by the program dftables  not supplied in the distribution, but is built by the program dftables
# Line 154  The distribution should contain the foll Line 347  The distribution should contain the foll
347      headers:      headers:
348    
349    dftables.c            auxiliary program for building chartables.c    dftables.c            auxiliary program for building chartables.c
350    
351    get.c                 )    get.c                 )
352    maketables.c          )    maketables.c          )
353    study.c               ) source of    study.c               ) source of the functions
354    pcre.c                )   the functions    pcre.c                )   in the library
355    pcreposix.c           )    pcreposix.c           )
356    pcre.h                header for the external API    printint.c            )
357    
358      ucp.c                 )
359      ucp.h                 ) source for the code that is used for
360      ucpinternal.h         )   Unicode property handling
361      ucptable.c            )
362      ucptypetable.c        )
363    
364      pcre.in               "source" for the header for the external API; pcre.h
365                              is built from this by "configure"
366    pcreposix.h           header for the external POSIX wrapper API    pcreposix.h           header for the external POSIX wrapper API
367    internal.h            header for internal use    internal.h            header for internal use
368    config.in             template for config.h, which is built by configure    config.in             template for config.h, which is built by configure
# Line 170  The distribution should contain the foll Line 373  The distribution should contain the foll
373    ChangeLog             log of changes to the code    ChangeLog             log of changes to the code
374    INSTALL               generic installation instructions    INSTALL               generic installation instructions
375    LICENCE               conditions for the use of PCRE    LICENCE               conditions for the use of PCRE
376      COPYING               the same, using GNU's standard name
377    Makefile.in           template for Unix Makefile, which is built by configure    Makefile.in           template for Unix Makefile, which is built by configure
378    NEWS                  important changes in this release    NEWS                  important changes in this release
379    NON-UNIX-USE          notes on building PCRE on non-Unix systems    NON-UNIX-USE          notes on building PCRE on non-Unix systems
380    README                this file    README                this file
381    RunTest               a Unix shell script for running tests    RunTest.in            template for a Unix shell script for running tests
382    config.guess          ) files used by libtool,    config.guess          ) files used by libtool,
383    config.sub            )   used only when building a shared library    config.sub            )   used only when building a shared library
384    configure             a configuring shell script (built by autoconf)    configure             a configuring shell script (built by autoconf)
385    configure.in          the autoconf input used to build configure    configure.in          the autoconf input used to build configure
386    doc/Tech.Notes        notes on the encoding    doc/Tech.Notes        notes on the encoding
387    doc/pcre.3            man page source for the PCRE functions    doc/*.3               man page sources for the PCRE functions
388    doc/pcre.html         HTML version    doc/*.1               man page sources for pcregrep and pcretest
389    doc/pcre.txt          plain text version    doc/html/*            HTML documentation
390    doc/pcreposix.3       man page source for the POSIX wrapper API    doc/pcre.txt          plain text version of the man pages
391    doc/pcreposix.html    HTML version    doc/pcretest.txt      plain text documentation of test program
392    doc/pcreposix.txt     plain text version    doc/perltest.txt      plain text documentation of Perl test program
   doc/pcretest.txt      documentation of test program  
   doc/perltest.txt      documentation of Perl test program  
   doc/pgrep.1           man page source for the pgrep utility  
   doc/pgrep.html        HTML version  
   doc/pgrep.txt         plain text version  
393    install-sh            a shell script for installing files    install-sh            a shell script for installing files
394    ltconfig              ) files used to build "libtool",    libpcre.pc.in         "source" for libpcre.pc for pkg-config
395    ltmain.sh             )   used only when building a shared library    ltmain.sh             file used to build a libtool script
396    pcretest.c            test program    mkinstalldirs         script for making install directories
397      pcretest.c            comprehensive test program
398      pcredemo.c            simple demonstration of coding calls to PCRE
399    perltest              Perl test program    perltest              Perl test program
400    pgrep.c               source of a grep utility that uses PCRE    pcregrep.c            source of a grep utility that uses PCRE
401    testdata/testinput1   test data, compatible with Perl 5.004 and 5.005    pcre-config.in        source of script which retains PCRE information
402      testdata/testinput1   test data, compatible with Perl
403    testdata/testinput2   test data for error messages and non-Perl things    testdata/testinput2   test data for error messages and non-Perl things
404    testdata/testinput3   test data, compatible with Perl 5.005    testdata/testinput3   test data for locale-specific tests
405    testdata/testinput4   test data for locale-specific tests    testdata/testinput4   test data for UTF-8 tests compatible with Perl
406      testdata/testinput5   test data for other UTF-8 tests
407      testdata/testinput6   test data for Unicode property support tests
408    testdata/testoutput1  test results corresponding to testinput1    testdata/testoutput1  test results corresponding to testinput1
409    testdata/testoutput2  test results corresponding to testinput2    testdata/testoutput2  test results corresponding to testinput2
410    testdata/testoutput3  test results corresponding to testinput3    testdata/testoutput3  test results corresponding to testinput3
411    testdata/testoutput4  test results corresponding to testinput4    testdata/testoutput4  test results corresponding to testinput4
412      testdata/testoutput5  test results corresponding to testinput5
413      testdata/testoutput6  test results corresponding to testinput6
414    
415  (C) Auxiliary files for Win32 DLL  (C) Auxiliary files for Win32 DLL
416    
417    dll.mk    dll.mk
418      libpcre.def
419      libpcreposix.def
420    pcre.def    pcre.def
421    
422    (D) Auxiliary file for VPASCAL
423    
424      makevp.bat
425    
426  Philip Hazel <ph10@cam.ac.uk>  Philip Hazel <ph10@cam.ac.uk>
427  January 2000  September 2004

Legend:
Removed from v.41  
changed lines
  Added in v.75

  ViewVC Help
Powered by ViewVC 1.1.5