From 582b500cd996c96054615870fd13d6ab0ea77428 Mon Sep 17 00:00:00 2001 From: Jay Berkenbilt Date: Sat, 10 Oct 2009 15:10:05 +0000 Subject: start integrating windows port git-svn-id: svn+q:///qpdf/trunk@757 71b93d88-0707-0410-a8cf-f5a4172ac649 --- external-libs/pcre/README | 365 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 365 insertions(+) create mode 100644 external-libs/pcre/README (limited to 'external-libs/pcre/README') diff --git a/external-libs/pcre/README b/external-libs/pcre/README new file mode 100644 index 00000000..879ba04f --- /dev/null +++ b/external-libs/pcre/README @@ -0,0 +1,365 @@ +README file for PCRE (Perl-compatible regular expression library) +----------------------------------------------------------------- + +The latest release of PCRE is always available from + + ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-xxx.tar.gz + +Please read the NEWS file if you are upgrading from a previous release. + +PCRE has its own native API, but a set of "wrapper" functions that are based on +the POSIX API are also supplied in the library libpcreposix. Note that this +just provides a POSIX calling interface to PCRE: the regular expressions +themselves still follow Perl syntax and semantics. The header file +for the POSIX-style functions is called pcreposix.h. The official POSIX name is +regex.h, but I didn't want to risk possible problems with existing files of +that name by distributing it that way. To use it with an existing program that +uses the POSIX API, it 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, you must take care when linking programs to +ensure that they link with PCRE's libpcreposix library. Otherwise they may pick +up the "real" POSIX functions of the same name. + + +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 + +where there is also a README file giving brief descriptions of what they are. +Several of them provide support for compiling PCRE on various flavours of +Windows systems (I myself do not use Windows). Some are complete in themselves; +others are pointers to URLs containing relevant files. + + +Building PCRE on a Unix-like system +----------------------------------- + +To build PCRE on a Unix-like system, 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 +INSTALL. + +Most commonly, people build PCRE within its own distribution directory, and in +this case, on many systems, just running "./configure" is sufficient, but the +usual methods of changing standard defaults are available. For example, + +CFLAGS='-O2 -Wall' ./configure --prefix=/opt/local + +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 + +There are some optional features that can be included or omitted from the PCRE +library. You can read more about them in the pcrebuild man page. + +. If you want to make use of the support for UTF-8 character strings in PCRE, + you must add --enable-utf8 to the "configure" command. Without it, the code + for handling UTF-8 is not included in the library. (Even when included, it + still has to be enabled by an option at run time.) + +. You can build PCRE to recognized CR or NL as the newline character, instead + of whatever your compiler uses for "\n", by adding --newline-is-cr or + --newline-is-nl to the "configure" command, respectively. Only do this if you + really understand what you are doing. On traditional Unix-like systems, the + newline character is NL. + +. 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. You can increase this threshold by setting, for example, + + --with-posix-malloc-threshold=20 + + on the "configure" command. + +. PCRE has a counter which can be set to limit the amount of resources it uses. + 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 discussion on the pcreapi + 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. You can + increase it even more by setting --with-link-size=4, but this is unlikely + ever to be necessary. If you build PCRE with an increased link size, test 2 + (and 5 if you are using UTF-8) will fail. Part of the output of these tests + is a representation of the compiled pattern, and this changes with the link + size. + +. You can build PCRE so that its match() function does not call itself + recursively. Instead, it uses blocks of data from the heap via 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. + +The "configure" script builds five files: + +. libtool is a script that builds shared and/or static libraries +. Makefile is built by copying Makefile.in and making substitutions. +. config.h is built by copying config.in and making substitutions. +. pcre-config is built by copying pcre-config.in and making substitutions. +. RunTest is a script for running tests + +Once "configure" has run, you can run "make". It builds two libraries called +libpcre and libpcreposix, a test program called pcretest, and the pcregrep +command. You can use "make install" to copy these, the public header files +pcre.h and pcreposix.h, and the man pages to appropriate live directories on +your system, in the normal way. + +Running "make install" also 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. + + +Shared libraries on Unix-like systems +------------------------------------- + +The default distribution builds PCRE as two shared libraries and two 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 source 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 on a Unix-like system +------------------------------------- + +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, during the building +process, the dftables.c source file is compiled *and run* on the local host, in +order to generate the default character tables (the chartables.c file). It +therefore needs to be compiled with the local compiler, not the cross compiler. +You can do this by specifying CC_FOR_BUILD (and if necessary CFLAGS_FOR_BUILD) +when calling the "configure" command. If they are not specified, they default +to the values of CC and CFLAGS. + + +Building on non-Unix systems +---------------------------- + +For a non-Unix system, read the comments in the file NON-UNIX-USE, though if +the system supports the use of "configure" and "make" you may be able to build +PCRE in the same way as for Unix systems. + +PCRE has been compiled on Windows systems and on Macintoshes, but I don't know +the details because I don't use those systems. It should be straightforward to +build PCRE on any system that has a Standard C compiler, because it uses only +Standard C functions. + + +Testing PCRE +------------ + +To test PCRE on a Unix system, run the RunTest script that is created by the +configuring process. (This can also be run by "make runtest", "make check", or +"make test".) For other systems, see the instructions in NON-UNIX-USE. + +The script runs the pcretest test program (which is documented in its own man +page) on each of the testinput files (in the testdata directory) in turn, +and compares the output with the contents of the corresponding testoutput file. +A file called testtry is used to hold the output from pcretest. To run pcretest +on just one of the test files, give its number as an argument to RunTest, for +example: + + RunTest 2 + +The first file can also be fed directly into the perltest 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_info(), 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 flag 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. + +The fourth test checks the UTF-8 support. It is not run automatically unless +PCRE is built with UTF-8 support. To do this you must set --enable-utf8 when +running "configure". This file can be also fed directly to the perltest script, +provided you are running Perl 5.8 or higher. (For Perl 5.6, a small patch, +commented in the script, can be be used.) + +The fifth and final file tests error handling with UTF-8 encoding, and internal +UTF-8 features of PCRE that are not relevant to Perl. + + +Character tables +---------------- + +PCRE uses four tables for manipulating and identifying characters. 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 chartables.c contains the default set of tables. This is +not supplied in the distribution, but 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 chartables.c and then re-building PCRE. If you do this, you should +probably also edit Makefile to ensure that the file doesn't ever get +re-generated. + +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. + +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. + + +Manifest +-------- + +The distribution should contain the following files: + +(A) The actual source files of the PCRE library functions and their + headers: + + dftables.c auxiliary program for building chartables.c + get.c ) + maketables.c ) + study.c ) source of + pcre.c ) the functions + pcreposix.c ) + printint.c ) + pcre.in "source" for the header for the external API; pcre.h + is built from this by "configure" + pcreposix.h header for the external POSIX wrapper API + internal.h header for internal use + config.in template for config.h, which is built by configure + +(B) Auxiliary files: + + AUTHORS information about the author of PCRE + ChangeLog log of changes to the code + 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 + NEWS important changes in this release + NON-UNIX-USE notes on building PCRE on non-Unix systems + README this file + RunTest.in template for a Unix shell script for running tests + config.guess ) files used by libtool, + config.sub ) used only when building a shared library + configure a configuring shell script (built by autoconf) + configure.in the autoconf input used to build configure + doc/Tech.Notes notes on the encoding + doc/*.3 man page sources for the PCRE functions + doc/*.1 man page sources for pcregrep and pcretest + 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 + ltmain.sh file used to build a libtool script + pcretest.c comprehensive test program + pcredemo.c simple demonstration of coding calls to PCRE + perltest Perl test program + pcregrep.c source of a grep utility that uses PCRE + pcre-config.in source of script which retains PCRE information + testdata/testinput1 test data, compatible with Perl + testdata/testinput2 test data for error messages and non-Perl things + testdata/testinput3 test data for locale-specific tests + testdata/testinput4 test data for UTF-8 tests compatible with Perl + testdata/testinput5 test data for other UTF-8 tests + testdata/testoutput1 test results corresponding to testinput1 + testdata/testoutput2 test results corresponding to testinput2 + testdata/testoutput3 test results corresponding to testinput3 + testdata/testoutput4 test results corresponding to testinput4 + testdata/testoutput5 test results corresponding to testinput5 + +(C) Auxiliary files for Win32 DLL + + dll.mk + pcre.def + +(D) Auxiliary file for VPASCAL + + makevp.bat + +Philip Hazel +December 2003 -- cgit v1.2.3-54-g00ecf