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README 

        
README file for PCRE (Perl-compatible regular expression library)

-----------------------------------------------------------------



NOTE: This set of files relates to PCRE releases that use the original API,

with library names libpcre, libpcre16, and libpcre32. January 2015 saw the

first release of a new API, known as PCRE2, with release numbers starting at

10.00 and library names libpcre2-8, libpcre2-16, and libpcre2-32. The old

libraries (now called PCRE1) are now at end of life, and 8.45 is the final

release. New projects are advised to use the new PCRE2 libraries.



The latest release of PCRE1 is always available in three alternative formats

from:



  https://ftp.pcre.org/pub/pcre/pcre-x.xx.tar.gz

  https://ftp.pcre.org/pub/pcre/pcre-x.xx.tar.bz2

  https://ftp.pcre.org/pub/pcre/pcre-x.xx.tar.zip



There is a mailing list for discussion about the development of PCRE at

[email protected]. You can access the archives and subscribe or manage your

subscription here:



   https://lists.exim.org/mailman/listinfo/pcre-dev



Please read the NEWS file if you are upgrading from a previous release.

The contents of this README file are:



  The PCRE APIs

  Documentation for PCRE

  Contributions by users of PCRE

  Building PCRE on non-Unix-like systems

  Building PCRE without using autotools

  Building PCRE using autotools

  Retrieving configuration information

  Shared libraries

  Cross-compiling using autotools

  Using HP's ANSI C++ compiler (aCC)

  Compiling in Tru64 using native compilers

  Using Sun's compilers for Solaris

  Using PCRE from MySQL

  Making new tarballs

  Testing PCRE

  Character tables

  File manifest



The PCRE APIs

-------------



PCRE is written in C, and it has its own API. There are three sets of

functions, one for the 8-bit library, which processes strings of bytes, one for

the 16-bit library, which processes strings of 16-bit values, and one for the

32-bit library, which processes strings of 32-bit values. The distribution also

includes a set of C++ wrapper functions (see the pcrecpp man page for details),

courtesy of Google Inc., which can be used to call the 8-bit PCRE library from

C++. Other C++ wrappers have been created from time to time. See, for example:

https://github.com/YasserAsmi/regexp, which aims to be simple and similar in

style to the C API.



The distribution also contains a set of C wrapper functions (again, just for

the 8-bit library) that are based on the POSIX regular expression API (see the

pcreposix man page). These end up in the library called libpcreposix. Note that

this just provides a POSIX calling interface to PCRE; the regular expressions

themselves still follow Perl syntax and semantics. The POSIX API is restricted,

and does not give full access to all of PCRE's facilities.



The header file for the POSIX-style functions is called pcreposix.h. The

official POSIX name is regex.h, but I did not want to risk possible problems

with existing files of that name by distributing it that way. To use PCRE with

an existing program that uses the POSIX API, pcreposix.h will have to be

renamed or pointed at by a link.



If you are using the POSIX interface to PCRE and there is already a POSIX regex

library installed on your system, as well as worrying about the regex.h header

file (as mentioned above), you must also take care when linking programs to

ensure that they link with PCRE's libpcreposix library. Otherwise they may pick

up the POSIX functions of the same name from the other library.



One way of avoiding this confusion is to compile PCRE with the addition of

-Dregcomp=PCREregcomp (and similarly for the other POSIX functions) to the

compiler flags (CFLAGS if you are using "configure" -- see below). This has the

effect of renaming the functions so that the names no longer clash. Of course,

you have to do the same thing for your applications, or write them using the

new names.



Documentation for PCRE

----------------------



If you install PCRE in the normal way on a Unix-like system, you will end up

with a set of man pages whose names all start with "pcre". The one that is just

called "pcre" lists all the others. In addition to these man pages, the PCRE

documentation is supplied in two other forms:



  1. There are files called doc/pcre.txt, doc/pcregrep.txt, and

     doc/pcretest.txt in the source distribution. The first of these is a

     concatenation of the text forms of all the section 3 man pages except

     the listing of pcredemo.c and those that summarize individual functions.

     The other two are the text forms of the section 1 man pages for the

     pcregrep and pcretest commands. These text forms are provided for ease of

     scanning with text editors or similar tools. They are installed in

     /share/doc/pcre, where  is the installation prefix

     (defaulting to /usr/local).



  2. A set of files containing all the documentation in HTML form, hyperlinked

     in various ways, and rooted in a file called index.html, is distributed in

     doc/html and installed in /share/doc/pcre/html.



Users of PCRE have contributed files containing the documentation for various

releases in CHM format. These can be found in the Contrib directory of the FTP

site (see next section).



Contributions by users of PCRE

------------------------------



You can find contributions from PCRE users in the directory



  ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/Contrib



There is a README file giving brief descriptions of what they are. Some are

complete in themselves; others are pointers to URLs containing relevant files.

Some of this material is likely to be well out-of-date. Several of the earlier

contributions provided support for compiling PCRE on various flavours of

Windows (I myself do not use Windows). Nowadays there is more Windows support

in the standard distribution, so these contibutions have been archived.



A PCRE user maintains downloadable Windows binaries of the pcregrep and

pcretest programs here:



  http://www.rexegg.com/pcregrep-pcretest.html



Building PCRE on non-Unix-like systems

--------------------------------------



For a non-Unix-like system, please read the comments in the file

NON-AUTOTOOLS-BUILD, though if your system supports the use of "configure" and

"make" you may be able to build PCRE using autotools in the same way as for

many Unix-like systems.



PCRE can also be configured using the GUI facility provided by CMake's

cmake-gui command. This creates Makefiles, solution files, etc. The file

NON-AUTOTOOLS-BUILD has information about CMake.



PCRE has been compiled on many different operating systems. It should be

straightforward to build PCRE on any system that has a Standard C compiler and

library, because it uses only Standard C functions.



Building PCRE without using autotools

-------------------------------------



The use of autotools (in particular, libtool) is problematic in some

environments, even some that are Unix or Unix-like. See the NON-AUTOTOOLS-BUILD

file for ways of building PCRE without using autotools.



Building PCRE using autotools

-----------------------------



If you are using HP's ANSI C++ compiler (aCC), please see the special note

in the section entitled "Using HP's ANSI C++ compiler (aCC)" below.



The following instructions assume the use of the widely used "configure; make;

make install" (autotools) process.



To build PCRE on system that supports autotools, first run the "configure"

command from the PCRE distribution directory, with your current directory set

to the directory where you want the files to be created. This command is a

standard GNU "autoconf" configuration script, for which generic instructions

are supplied in the file INSTALL.



Most commonly, people build PCRE within its own distribution directory, and in

this case, on many systems, just running "./configure" is sufficient. However,

the usual methods of changing standard defaults are available. For example:



CFLAGS='-O2 -Wall' ./configure --prefix=/opt/local



This command specifies that the C compiler should be run with the flags '-O2

-Wall' instead of the default, and that "make install" should install PCRE

under /opt/local instead of the default /usr/local.



If you want to build in a different directory, just run "configure" with that

directory as current. For example, suppose you have unpacked the PCRE source

into /source/pcre/pcre-xxx, but you want to build it in /build/pcre/pcre-xxx:



cd /build/pcre/pcre-xxx

/source/pcre/pcre-xxx/configure



PCRE is written in C and is normally compiled as a C library. However, it is

possible to build it as a C++ library, though the provided building apparatus

does not have any features to support this.



There are some optional features that can be included or omitted from the PCRE

library. They are also documented in the pcrebuild man page.



. By default, both shared and static libraries are built. You can change this

  by adding one of these options to the "configure" command:



  --disable-shared

  --disable-static



  (See also "Shared libraries on Unix-like systems" below.)



. By default, only the 8-bit library is built. If you add --enable-pcre16 to

  the "configure" command, the 16-bit library is also built. If you add

  --enable-pcre32 to the "configure" command, the 32-bit library is also built.

  If you want only the 16-bit or 32-bit library, use --disable-pcre8 to disable

  building the 8-bit library.



. If you are building the 8-bit library and want to suppress the building of

  the C++ wrapper library, you can add --disable-cpp to the "configure"

  command. Otherwise, when "configure" is run without --disable-pcre8, it will

  try to find a C++ compiler and C++ header files, and if it succeeds, it will

  try to build the C++ wrapper.



. If you want to include support for just-in-time compiling, which can give

  large performance improvements on certain platforms, add --enable-jit to the

  "configure" command. This support is available only for certain hardware

  architectures. If you try to enable it on an unsupported architecture, there

  will be a compile time error.



. When JIT support is enabled, pcregrep automatically makes use of it, unless

  you add --disable-pcregrep-jit to the "configure" command.



. If you want to make use of the support for UTF-8 Unicode character strings in

  the 8-bit library, or UTF-16 Unicode character strings in the 16-bit library,

  or UTF-32 Unicode character strings in the 32-bit library, you must add

  --enable-utf to the "configure" command. Without it, the code for handling

  UTF-8, UTF-16 and UTF-8 is not included in the relevant library. Even

  when --enable-utf is included, the use of a UTF encoding still has to be

  enabled by an option at run time. When PCRE is compiled with this option, its

  input can only either be ASCII or UTF-8/16/32, even when running on EBCDIC

  platforms. It is not possible to use both --enable-utf and --enable-ebcdic at

  the same time.



. There are no separate options for enabling UTF-8, UTF-16 and UTF-32

  independently because that would allow ridiculous settings such as requesting

  UTF-16 support while building only the 8-bit library. However, the option

  --enable-utf8 is retained for backwards compatibility with earlier releases

  that did not support 16-bit or 32-bit character strings. It is synonymous with

  --enable-utf. It is not possible to configure one library with UTF support

  and the other without in the same configuration.



. If, in addition to support for UTF-8/16/32 character strings, you want to

  include support for the \P, \p, and \X sequences that recognize Unicode

  character properties, you must add --enable-unicode-properties to the

  "configure" command. This adds about 30K to the size of the library (in the

  form of a property table); only the basic two-letter properties such as Lu

  are supported.



. You can build PCRE to recognize either CR or LF or the sequence CRLF or any

  of the preceding, or any of the Unicode newline sequences as indicating the

  end of a line. Whatever you specify at build time is the default; the caller

  of PCRE can change the selection at run time. The default newline indicator

  is a single LF character (the Unix standard). You can specify the default

  newline indicator by adding --enable-newline-is-cr or --enable-newline-is-lf

  or --enable-newline-is-crlf or --enable-newline-is-anycrlf or

  --enable-newline-is-any to the "configure" command, respectively.



  If you specify --enable-newline-is-cr or --enable-newline-is-crlf, some of

  the standard tests will fail, because the lines in the test files end with

  LF. Even if the files are edited to change the line endings, there are likely

  to be some failures. With --enable-newline-is-anycrlf or

  --enable-newline-is-any, many tests should succeed, but there may be some

  failures.



. By default, the sequence \R in a pattern matches any Unicode line ending

  sequence. This is independent of the option specifying what PCRE considers to

  be the end of a line (see above). However, the caller of PCRE can restrict \R

  to match only CR, LF, or CRLF. You can make this the default by adding

  --enable-bsr-anycrlf to the "configure" command (bsr = "backslash R").



. When called via the POSIX interface, PCRE uses malloc() to get additional

  storage for processing capturing parentheses if there are more than 10 of

  them in a pattern. You can increase this threshold by setting, for example,



  --with-posix-malloc-threshold=20



  on the "configure" command.



. PCRE has a counter that limits the depth of nesting of parentheses in a

  pattern. This limits the amount of system stack that a pattern uses when it

  is compiled. The default is 250, but you can change it by setting, for

  example,



  --with-parens-nest-limit=500



. PCRE has a counter that can be set to limit the amount of resources it uses

  when matching a pattern. If the limit is exceeded during a match, the match

  fails. The default is ten million. You can change the default by setting, for

  example,



  --with-match-limit=500000



  on the "configure" command. This is just the default; individual calls to

  pcre_exec() can supply their own value. There is more discussion on the

  pcreapi man page.



. There is a separate counter that limits the depth of recursive function calls

  during a matching process. This also has a default of ten million, which is

  essentially "unlimited". You can change the default by setting, for example,



  --with-match-limit-recursion=500000



  Recursive function calls use up the runtime stack; running out of stack can

  cause programs to crash in strange ways. There is a discussion about stack

  sizes in the pcrestack man page.



. The default maximum compiled pattern size is around 64K. You can increase

  this by adding --with-link-size=3 to the "configure" command. In the 8-bit

  library, PCRE then uses three bytes instead of two for offsets to different

  parts of the compiled pattern. In the 16-bit library, --with-link-size=3 is

  the same as --with-link-size=4, which (in both libraries) uses four-byte

  offsets. Increasing the internal link size reduces performance. In the 32-bit

  library, the only supported link size is 4.



. You can build PCRE so that its internal match() function that is called from

  pcre_exec() does not call itself recursively. Instead, it uses memory blocks

  obtained from the heap via the special functions pcre_stack_malloc() and

  pcre_stack_free() to save data that would otherwise be saved on the stack. To

  build PCRE like this, use



  --disable-stack-for-recursion



  on the "configure" command. PCRE runs more slowly in this mode, but it may be

  necessary in environments with limited stack sizes. This applies only to the

  normal execution of the pcre_exec() function; if JIT support is being

  successfully used, it is not relevant. Equally, it does not apply to

  pcre_dfa_exec(), which does not use deeply nested recursion. There is a

  discussion about stack sizes in the pcrestack man page.



. For speed, PCRE uses four tables for manipulating and identifying characters

  whose code point values are less than 256. By default, it uses a set of

  tables for ASCII encoding that is part of the distribution. If you specify



  --enable-rebuild-chartables



  a program called dftables is compiled and run in the default C locale when

  you obey "make". It builds a source file called pcre_chartables.c. If you do

  not specify this option, pcre_chartables.c is created as a copy of

  pcre_chartables.c.dist. See "Character tables" below for further information.



. It is possible to compile PCRE for use on systems that use EBCDIC as their

  character code (as opposed to ASCII/Unicode) by specifying



  --enable-ebcdic



  This automatically implies --enable-rebuild-chartables (see above). However,

  when PCRE is built this way, it always operates in EBCDIC. It cannot support

  both EBCDIC and UTF-8/16/32. There is a second option, --enable-ebcdic-nl25,

  which specifies that the code value for the EBCDIC NL character is 0x25

  instead of the default 0x15.



. In environments where valgrind is installed, if you specify



  --enable-valgrind



  PCRE will use valgrind annotations to mark certain memory regions as

  unaddressable. This allows it to detect invalid memory accesses, and is

  mostly useful for debugging PCRE itself.



. In environments where the gcc compiler is used and lcov version 1.6 or above

  is installed, if you specify



  --enable-coverage



  the build process implements a code coverage report for the test suite. The

  report is generated by running "make coverage". If ccache is installed on

  your system, it must be disabled when building PCRE for coverage reporting.

  You can do this by setting the environment variable CCACHE_DISABLE=1 before

  running "make" to build PCRE. There is more information about coverage

  reporting in the "pcrebuild" documentation.



. The pcregrep program currently supports only 8-bit data files, and so

  requires the 8-bit PCRE library. It is possible to compile pcregrep to use

  libz and/or libbz2, in order to read .gz and .bz2 files (respectively), by

  specifying one or both of



  --enable-pcregrep-libz

  --enable-pcregrep-libbz2



  Of course, the relevant libraries must be installed on your system.



. The default size (in bytes) of the internal buffer used by pcregrep can be

  set by, for example:



  --with-pcregrep-bufsize=51200



  The value must be a plain integer. The default is 20480.



. It is possible to compile pcretest so that it links with the libreadline

  or libedit libraries, by specifying, respectively,



  --enable-pcretest-libreadline or --enable-pcretest-libedit



  If this is done, when pcretest's input is from a terminal, it reads it using

  the readline() function. This provides line-editing and history facilities.

  Note that libreadline is GPL-licenced, so if you distribute a binary of

  pcretest linked in this way, there may be licensing issues. These can be

  avoided by linking with libedit (which has a BSD licence) instead.



  Enabling libreadline causes the -lreadline option to be added to the pcretest

  build. In many operating environments with a sytem-installed readline

  library this is sufficient. However, in some environments (e.g. if an

  unmodified distribution version of readline is in use), it may be necessary

  to specify something like LIBS="-lncurses" as well. This is because, to quote

  the readline INSTALL, "Readline uses the termcap functions, but does not link

  with the termcap or curses library itself, allowing applications which link

  with readline the to choose an appropriate library." If you get error

  messages about missing functions tgetstr, tgetent, tputs, tgetflag, or tgoto,

  this is the problem, and linking with the ncurses library should fix it.



The "configure" script builds the following files for the basic C library:



. Makefile             the makefile that builds the library

. config.h             build-time configuration options for the library

. pcre.h               the public PCRE header file

. pcre-config          script that shows the building settings such as CFLAGS

                         that were set for "configure"

. libpcre.pc         ) data for the pkg-config command

. libpcre16.pc       )

. libpcre32.pc       )

. libpcreposix.pc    )

. libtool              script that builds shared and/or static libraries



Versions of config.h and pcre.h are distributed in the PCRE tarballs under the

names config.h.generic and pcre.h.generic. These are provided for those who

have to built PCRE without using "configure" or CMake. If you use "configure"

or CMake, the .generic versions are not used.



When building the 8-bit library, if a C++ compiler is found, the following

files are also built:



. libpcrecpp.pc        data for the pkg-config command

. pcrecpparg.h         header file for calling PCRE via the C++ wrapper

. pcre_stringpiece.h   header for the C++ "stringpiece" functions



The "configure" script also creates config.status, which is an executable

script that can be run to recreate the configuration, and config.log, which

contains compiler output from tests that "configure" runs.



Once "configure" has run, you can run "make". This builds the the libraries

libpcre, libpcre16 and/or libpcre32, and a test program called pcretest. If you

enabled JIT support with --enable-jit, a test program called pcre_jit_test is

built as well.



If the 8-bit library is built, libpcreposix and the pcregrep command are also

built, and if a C++ compiler was found on your system, and you did not disable

it with --disable-cpp, "make" builds the C++ wrapper library, which is called

libpcrecpp, as well as some test programs called pcrecpp_unittest,

pcre_scanner_unittest, and pcre_stringpiece_unittest.



The command "make check" runs all the appropriate tests. Details of the PCRE

tests are given below in a separate section of this document.



You can use "make install" to install PCRE into live directories on your

system. The following are installed (file names are all relative to the

 that is set when "configure" is run):



  Commands (bin):

    pcretest

    pcregrep (if 8-bit support is enabled)

    pcre-config



  Libraries (lib):

    libpcre16     (if 16-bit support is enabled)

    libpcre32     (if 32-bit support is enabled)

    libpcre       (if 8-bit support is enabled)

    libpcreposix  (if 8-bit support is enabled)

    libpcrecpp    (if 8-bit and C++ support is enabled)



  Configuration information (lib/pkgconfig):

    libpcre16.pc

    libpcre32.pc

    libpcre.pc

    libpcreposix.pc

    libpcrecpp.pc (if C++ support is enabled)



  Header files (include):

    pcre.h

    pcreposix.h

    pcre_scanner.h      )

    pcre_stringpiece.h  ) if C++ support is enabled

    pcrecpp.h           )

    pcrecpparg.h        )



  Man pages (share/man/man{1,3}):

    pcregrep.1

    pcretest.1

    pcre-config.1

    pcre.3

    pcre*.3 (lots more pages, all starting "pcre")



  HTML documentation (share/doc/pcre/html):

    index.html

    *.html (lots more pages, hyperlinked from index.html)



  Text file documentation (share/doc/pcre):

    AUTHORS

    COPYING

    ChangeLog

    LICENCE

    NEWS

    README

    pcre.txt         (a concatenation of the man(3) pages)

    pcretest.txt     the pcretest man page

    pcregrep.txt     the pcregrep man page

    pcre-config.txt  the pcre-config man page



If you want to remove PCRE from your system, you can run "make uninstall".

This removes all the files that "make install" installed. However, it does not

remove any directories, because these are often shared with other programs.



Retrieving configuration information

------------------------------------



Running "make install" installs the command pcre-config, which can be used to

recall information about the PCRE configuration and installation. For example:



  pcre-config --version



prints the version number, and



  pcre-config --libs



outputs information about where the library is installed. This command can be

included in makefiles for programs that use PCRE, saving the programmer from

having to remember too many details.



The pkg-config command is another system for saving and retrieving information

about installed libraries. Instead of separate commands for each library, a

single command is used. For example:



  pkg-config --cflags pcre



The data is held in *.pc files that are installed in a directory called

/lib/pkgconfig.



Shared libraries

----------------



The default distribution builds PCRE as shared libraries and static libraries,

as long as the operating system supports shared libraries. Shared library

support relies on the "libtool" script which is built as part of the

"configure" process.



The libtool script is used to compile and link both shared and static

libraries. They are placed in a subdirectory called .libs when they are newly

built. The programs pcretest and pcregrep are built to use these uninstalled

libraries (by means of wrapper scripts in the case of shared libraries). When

you use "make install" to install shared libraries, pcregrep and pcretest are

automatically re-built to use the newly installed shared libraries before being

installed themselves. However, the versions left in the build directory still

use the uninstalled libraries.



To build PCRE using static libraries only you must use --disable-shared when

configuring it. For example:



./configure --prefix=/usr/gnu --disable-shared



Then run "make" in the usual way. Similarly, you can use --disable-static to

build only shared libraries.



Cross-compiling using autotools

-------------------------------



You can specify CC and CFLAGS in the normal way to the "configure" command, in

order to cross-compile PCRE for some other host. However, you should NOT

specify --enable-rebuild-chartables, because if you do, the dftables.c source

file is compiled and run on the local host, in order to generate the inbuilt

character tables (the pcre_chartables.c file). This will probably not work,

because dftables.c needs to be compiled with the local compiler, not the cross

compiler.



When --enable-rebuild-chartables is not specified, pcre_chartables.c is created

by making a copy of pcre_chartables.c.dist, which is a default set of tables

that assumes ASCII code. Cross-compiling with the default tables should not be

a problem.



If you need to modify the character tables when cross-compiling, you should

move pcre_chartables.c.dist out of the way, then compile dftables.c by hand and

run it on the local host to make a new version of pcre_chartables.c.dist.

Then when you cross-compile PCRE this new version of the tables will be used.



Using HP's ANSI C++ compiler (aCC)

----------------------------------



Unless C++ support is disabled by specifying the "--disable-cpp" option of the

"configure" script, you must include the "-AA" option in the CXXFLAGS

environment variable in order for the C++ components to compile correctly.



Also, note that the aCC compiler on PA-RISC platforms may have a defect whereby

needed libraries fail to get included when specifying the "-AA" compiler

option. If you experience unresolved symbols when linking the C++ programs,

use the workaround of specifying the following environment variable prior to

running the "configure" script:



  CXXLDFLAGS="-lstd_v2 -lCsup_v2"



Compiling in Tru64 using native compilers

-----------------------------------------



The following error may occur when compiling with native compilers in the Tru64

operating system:



  CXX    libpcrecpp_la-pcrecpp.lo

cxx: Error: /usr/lib/cmplrs/cxx/V7.1-006/include/cxx/iosfwd, line 58: #error

          directive: "cannot include iosfwd -- define __USE_STD_IOSTREAM to

          override default - see section 7.1.2 of the C++ Using Guide"

#error "cannot include iosfwd -- define __USE_STD_IOSTREAM to override default

- see section 7.1.2 of the C++ Using Guide"



This may be followed by other errors, complaining that 'namespace "std" has no

member'. The solution to this is to add the line



#define __USE_STD_IOSTREAM 1



to the config.h file.



Using Sun's compilers for Solaris

---------------------------------



A user reports that the following configurations work on Solaris 9 sparcv9 and

Solaris 9 x86 (32-bit):



  Solaris 9 sparcv9: ./configure --disable-cpp CC=/bin/cc CFLAGS="-m64 -g"

  Solaris 9 x86:     ./configure --disable-cpp CC=/bin/cc CFLAGS="-g"



Using PCRE from MySQL

---------------------



On systems where both PCRE and MySQL are installed, it is possible to make use

of PCRE from within MySQL, as an alternative to the built-in pattern matching.

There is a web page that tells you how to do this:



  http://www.mysqludf.org/lib_mysqludf_preg/index.php



Making new tarballs

-------------------



The command "make dist" creates three PCRE tarballs, in tar.gz, tar.bz2, and

zip formats. The command "make distcheck" does the same, but then does a trial

build of the new distribution to ensure that it works.



If you have modified any of the man page sources in the doc directory, you

should first run the PrepareRelease script before making a distribution. This

script creates the .txt and HTML forms of the documentation from the man pages.



Testing PCRE

------------



To test the basic PCRE library on a Unix-like system, run the RunTest script.

There is another script called RunGrepTest that tests the options of the

pcregrep command. If the C++ wrapper library is built, three test programs

called pcrecpp_unittest, pcre_scanner_unittest, and pcre_stringpiece_unittest

are also built. When JIT support is enabled, another test program called

pcre_jit_test is built.



Both the scripts and all the program tests are run if you obey "make check" or

"make test". For other environments, see the instructions in

NON-AUTOTOOLS-BUILD.



The RunTest script runs the pcretest test program (which is documented in its

own man page) on each of the relevant testinput files in the testdata

directory, and compares the output with the contents of the corresponding

testoutput files. RunTest uses a file called testtry to hold the main output

from pcretest. Other files whose names begin with "test" are used as working

files in some tests.



Some tests are relevant only when certain build-time options were selected. For

example, the tests for UTF-8/16/32 support are run only if --enable-utf was

used. RunTest outputs a comment when it skips a test.



Many of the tests that are not skipped are run up to three times. The second

run forces pcre_study() to be called for all patterns except for a few in some

tests that are marked "never study" (see the pcretest program for how this is

done). If JIT support is available, the non-DFA tests are run a third time,

this time with a forced pcre_study() with the PCRE_STUDY_JIT_COMPILE option.

This testing can be suppressed by putting "nojit" on the RunTest command line.



The entire set of tests is run once for each of the 8-bit, 16-bit and 32-bit

libraries that are enabled. If you want to run just one set of tests, call

RunTest with either the -8, -16 or -32 option.



If valgrind is installed, you can run the tests under it by putting "valgrind"

on the RunTest command line. To run pcretest on just one or more specific test

files, give their numbers as arguments to RunTest, for example:



  RunTest 2 7 11



You can also specify ranges of tests such as 3-6 or 3- (meaning 3 to the

end), or a number preceded by ~ to exclude a test. For example:



  Runtest 3-15 ~10



This runs tests 3 to 15, excluding test 10, and just ~13 runs all the tests

except test 13. Whatever order the arguments are in, the tests are always run

in numerical order.



You can also call RunTest with the single argument "list" to cause it to output

a list of tests.



The first test file can be fed directly into the perltest.pl script to check

that Perl gives the same results. The only difference you should see is in the

first few lines, where the Perl version is given instead of the PCRE version.



The second set of tests check pcre_fullinfo(), pcre_study(),

pcre_copy_substring(), pcre_get_substring(), pcre_get_substring_list(), error

detection, and run-time flags that are specific to PCRE, as well as the POSIX

wrapper API. It also uses the debugging flags to check some of the internals of

pcre_compile().



If you build PCRE with a locale setting that is not the standard C locale, the

character tables may be different (see next paragraph). In some cases, this may

cause failures in the second set of tests. For example, in a locale where the

isprint() function yields TRUE for characters in the range 128-255, the use of

[:isascii:] inside a character class defines a different set of characters, and

this shows up in this test as a difference in the compiled code, which is being

listed for checking. Where the comparison test output contains [\x00-\x7f] the

test will contain [\x00-\xff], and similarly in some other cases. This is not a

bug in PCRE.



The third set of tests checks pcre_maketables(), the facility for building a

set of character tables for a specific locale and using them instead of the

default tables. The tests make use of the "fr_FR" (French) locale. Before

running the test, the script checks for the presence of this locale by running

the "locale" command. If that command fails, or if it doesn't include "fr_FR"

in the list of available locales, the third test cannot be run, and a comment

is output to say why. If running this test produces instances of the error



  ** Failed to set locale "fr_FR"



in the comparison output, it means that locale is not available on your system,

despite being listed by "locale". This does not mean that PCRE is broken.



[If you are trying to run this test on Windows, you may be able to get it to

work by changing "fr_FR" to "french" everywhere it occurs. Alternatively, use

RunTest.bat. The version of RunTest.bat included with PCRE 7.4 and above uses

Windows versions of test 2. More info on using RunTest.bat is included in the

document entitled NON-UNIX-USE.]



The fourth and fifth tests check the UTF-8/16/32 support and error handling and

internal UTF features of PCRE that are not relevant to Perl, respectively. The

sixth and seventh tests do the same for Unicode character properties support.



The eighth, ninth, and tenth tests check the pcre_dfa_exec() alternative

matching function, in non-UTF-8/16/32 mode, UTF-8/16/32 mode, and UTF-8/16/32

mode with Unicode property support, respectively.



The eleventh test checks some internal offsets and code size features; it is

run only when the default "link size" of 2 is set (in other cases the sizes

change) and when Unicode property support is enabled.



The twelfth test is run only when JIT support is available, and the thirteenth

test is run only when JIT support is not available. They test some JIT-specific

features such as information output from pcretest about JIT compilation.



The fourteenth, fifteenth, and sixteenth tests are run only in 8-bit mode, and

the seventeenth, eighteenth, and nineteenth tests are run only in 16/32-bit

mode. These are tests that generate different output in the two modes. They are

for general cases, UTF-8/16/32 support, and Unicode property support,

respectively.



The twentieth test is run only in 16/32-bit mode. It tests some specific

16/32-bit features of the DFA matching engine.



The twenty-first and twenty-second tests are run only in 16/32-bit mode, when

the link size is set to 2 for the 16-bit library. They test reloading

pre-compiled patterns.



The twenty-third and twenty-fourth tests are run only in 16-bit mode. They are

for general cases, and UTF-16 support, respectively.



The twenty-fifth and twenty-sixth tests are run only in 32-bit mode. They are

for general cases, and UTF-32 support, respectively.



Character tables

----------------



For speed, PCRE uses four tables for manipulating and identifying characters

whose code point values are less than 256. The final argument of the

pcre_compile() function is a pointer to a block of memory containing the

concatenated tables. A call to pcre_maketables() can be used to generate a set

of tables in the current locale. If the final argument for pcre_compile() is

passed as NULL, a set of default tables that is built into the binary is used.



The source file called pcre_chartables.c contains the default set of tables. By

default, this is created as a copy of pcre_chartables.c.dist, which contains

tables for ASCII coding. However, if --enable-rebuild-chartables is specified

for ./configure, a different version of pcre_chartables.c is built by the

program dftables (compiled from dftables.c), which uses the ANSI C character

handling functions such as isalnum(), isalpha(), isupper(), islower(), etc. to

build the table sources. This means that the default C locale which is set for

your system will control the contents of these default tables. You can change

the default tables by editing pcre_chartables.c and then re-building PCRE. If

you do this, you should take care to ensure that the file does not get

automatically re-generated. The best way to do this is to move

pcre_chartables.c.dist out of the way and replace it with your customized

tables.



When the dftables program is run as a result of --enable-rebuild-chartables,

it uses the default C locale that is set on your system. It does not pay

attention to the LC_xxx environment variables. In other words, it uses the

system's default locale rather than whatever the compiling user happens to have

set. If you really do want to build a source set of character tables in a

locale that is specified by the LC_xxx variables, you can run the dftables

program by hand with the -L option. For example:



  ./dftables -L pcre_chartables.c.special



The first two 256-byte tables provide lower casing and case flipping functions,

respectively. The next table consists of three 32-byte bit maps which identify

digits, "word" characters, and white space, respectively. These are used when

building 32-byte bit maps that represent character classes for code points less

than 256.



The final 256-byte table has bits indicating various character types, as

follows:



    1   white space character

    2   letter

    4   decimal digit

    8   hexadecimal digit

   16   alphanumeric or '_'

  128   regular expression metacharacter or binary zero



You should not alter the set of characters that contain the 128 bit, as that

will cause PCRE to malfunction.



File manifest

-------------



The distribution should contain the files listed below. Where a file name is

given as pcre[16|32]_xxx it means that there are three files, one with the name

pcre_xxx, one with the name pcre16_xx, and a third with the name pcre32_xxx.



(A) Source files of the PCRE library functions and their headers:



  dftables.c              auxiliary program for building pcre_chartables.c

                          when --enable-rebuild-chartables is specified



  pcre_chartables.c.dist  a default set of character tables that assume ASCII

                          coding; used, unless --enable-rebuild-chartables is

                          specified, by copying to pcre[16]_chartables.c



  pcreposix.c                )

  pcre[16|32]_byte_order.c   )

  pcre[16|32]_compile.c      )

  pcre[16|32]_config.c       )

  pcre[16|32]_dfa_exec.c     )

  pcre[16|32]_exec.c         )

  pcre[16|32]_fullinfo.c     )

  pcre[16|32]_get.c          ) sources for the functions in the library,

  pcre[16|32]_globals.c      )   and some internal functions that they use

  pcre[16|32]_jit_compile.c  )

  pcre[16|32]_maketables.c   )

  pcre[16|32]_newline.c      )

  pcre[16|32]_refcount.c     )

  pcre[16|32]_string_utils.c )

  pcre[16|32]_study.c        )

  pcre[16|32]_tables.c       )

  pcre[16|32]_ucd.c          )

  pcre[16|32]_version.c      )

  pcre[16|32]_xclass.c       )

  pcre_ord2utf8.c            )

  pcre_valid_utf8.c          )

  pcre16_ord2utf16.c         )

  pcre16_utf16_utils.c       )

  pcre16_valid_utf16.c       )

  pcre32_utf32_utils.c       )

  pcre32_valid_utf32.c       )



  pcre[16|32]_printint.c     ) debugging function that is used by pcretest,

                             )   and can also be #included in pcre_compile()



  pcre.h.in               template for pcre.h when built by "configure"

  pcreposix.h             header for the external POSIX wrapper API

  pcre_internal.h         header for internal use

  sljit/*                 16 files that make up the JIT compiler

  ucp.h                   header for Unicode property handling



  config.h.in             template for config.h, which is built by "configure"



  pcrecpp.h               public header file for the C++ wrapper

  pcrecpparg.h.in         template for another C++ header file

  pcre_scanner.h          public header file for C++ scanner functions

  pcrecpp.cc              )

  pcre_scanner.cc         ) source for the C++ wrapper library



  pcre_stringpiece.h.in   template for pcre_stringpiece.h, the header for the

                            C++ stringpiece functions

  pcre_stringpiece.cc     source for the C++ stringpiece functions



(B) Source files for programs that use PCRE:



  pcredemo.c              simple demonstration of coding calls to PCRE

  pcregrep.c              source of a grep utility that uses PCRE

  pcretest.c              comprehensive test program



(C) Auxiliary files:



  132html                 script to turn "man" pages into HTML

  AUTHORS                 information about the author of PCRE

  ChangeLog               log of changes to the code

  CleanTxt                script to clean nroff output for txt man pages

  Detrail                 script to remove trailing spaces

  HACKING                 some notes about the internals of PCRE

  INSTALL                 generic installation instructions

  LICENCE                 conditions for the use of PCRE

  COPYING                 the same, using GNU's standard name

  Makefile.in             ) template for Unix Makefile, which is built by

                          )   "configure"

  Makefile.am             ) the automake input that was used to create

                          )   Makefile.in

  NEWS                    important changes in this release

  NON-UNIX-USE            the previous name for NON-AUTOTOOLS-BUILD

  NON-AUTOTOOLS-BUILD     notes on building PCRE without using autotools

  PrepareRelease          script to make preparations for "make dist"

  README                  this file

  RunTest                 a Unix shell script for running tests

  RunGrepTest             a Unix shell script for pcregrep tests

  aclocal.m4              m4 macros (generated by "aclocal")

  config.guess            ) files used by libtool,

  config.sub              )   used only when building a shared library

  configure               a configuring shell script (built by autoconf)

  configure.ac            ) the autoconf input that was used to build

                          )   "configure" and config.h

  depcomp                 ) script to find program dependencies, generated by

                          )   automake

  doc/*.3                 man page sources for PCRE

  doc/*.1                 man page sources for pcregrep and pcretest

  doc/index.html.src      the base HTML page

  doc/html/*              HTML documentation

  doc/pcre.txt            plain text version of the man pages

  doc/pcretest.txt        plain text documentation of test program

  doc/perltest.txt        plain text documentation of Perl test program

  install-sh              a shell script for installing files

  libpcre16.pc.in         template for libpcre16.pc for pkg-config

  libpcre32.pc.in         template for libpcre32.pc for pkg-config

  libpcre.pc.in           template for libpcre.pc for pkg-config

  libpcreposix.pc.in      template for libpcreposix.pc for pkg-config

  libpcrecpp.pc.in        template for libpcrecpp.pc for pkg-config

  ltmain.sh               file used to build a libtool script

  missing                 ) common stub for a few missing GNU programs while

                          )   installing, generated by automake

  mkinstalldirs           script for making install directories

  perltest.pl             Perl test program

  pcre-config.in          source of script which retains PCRE information

  pcre_jit_test.c         test program for the JIT compiler

  pcrecpp_unittest.cc          )

  pcre_scanner_unittest.cc     ) test programs for the C++ wrapper

  pcre_stringpiece_unittest.cc )

  testdata/testinput*     test data for main library tests

  testdata/testoutput*    expected test results

  testdata/grep*          input and output for pcregrep tests

  testdata/*              other supporting test files



(D) Auxiliary files for cmake support



  cmake/COPYING-CMAKE-SCRIPTS

  cmake/FindPackageHandleStandardArgs.cmake

  cmake/FindEditline.cmake

  cmake/FindReadline.cmake

  CMakeLists.txt

  config-cmake.h.in



(E) Auxiliary files for VPASCAL



  makevp.bat

  makevp_c.txt

  makevp_l.txt

  pcregexp.pas



(F) Auxiliary files for building PCRE "by hand"



  pcre.h.generic          ) a version of the public PCRE header file

                          )   for use in non-"configure" environments

  config.h.generic        ) a version of config.h for use in non-"configure"

                          )   environments



(F) Miscellaneous



  RunTest.bat            a script for running tests under Windows



Philip Hazel

Email local part: Philip.Hazel

Email domain: gmail.com

Last updated: 15 June 2021