summaryrefslogtreecommitdiff
path: root/pcre/README.pcre
diff options
context:
space:
mode:
Diffstat (limited to 'pcre/README.pcre')
-rw-r--r--pcre/README.pcre1002
1 files changed, 1002 insertions, 0 deletions
diff --git a/pcre/README.pcre b/pcre/README.pcre
new file mode 100644
index 0000000..65f5e19
--- /dev/null
+++ b/pcre/README.pcre
@@ -0,0 +1,1002 @@
+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
+pcre-dev@exim.org. 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
+ <prefix>/share/doc/pcre, where <prefix> 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 <prefix>/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
+<prefix> 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
+<prefix>/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