From e15b64ef0365862f6ab98ad1643d58cd3a7e2c35 Mon Sep 17 00:00:00 2001 From: "Philip.Hazel" Date: Sun, 28 Sep 2014 17:39:28 +0000 Subject: [PATCH] More draft documentation. --- Makefile.am | 46 +- PrepareRelease | 16 +- doc/html/NON-AUTOTOOLS-BUILD.txt | 402 +++++++++++++++ doc/html/README.txt | 833 ++++++++++++++++++++++++++++++- doc/html/pcre2-config.html | 102 ++++ doc/html/pcre2.html | 182 +++++++ doc/html/pcre2grep.html | 759 ++++++++++++++++++++++++++++ doc/pcre2-config.1 | 86 ++++ doc/pcre2-config.txt | 81 +++ doc/pcre2.3 | 180 +++++++ doc/pcre2build.3 | 490 ++++++++++++++++++ doc/pcre2compat.3 | 190 +++++++ doc/pcre2grep.1 | 683 +++++++++++++++++++++++++ doc/pcre2grep.txt | 741 +++++++++++++++++++++++++++ src/pcre2grep.c | 2 +- src/pcre2test.c | 4 +- 16 files changed, 4754 insertions(+), 43 deletions(-) create mode 100644 doc/html/NON-AUTOTOOLS-BUILD.txt create mode 100644 doc/html/pcre2-config.html create mode 100644 doc/html/pcre2.html create mode 100644 doc/html/pcre2grep.html create mode 100644 doc/pcre2-config.1 create mode 100644 doc/pcre2-config.txt create mode 100644 doc/pcre2.3 create mode 100644 doc/pcre2build.3 create mode 100644 doc/pcre2compat.3 create mode 100644 doc/pcre2grep.1 create mode 100644 doc/pcre2grep.txt diff --git a/Makefile.am b/Makefile.am index 7df1e86..366b88c 100644 --- a/Makefile.am +++ b/Makefile.am @@ -6,29 +6,31 @@ AM_CPPFLAGS = -I$(builddir)/src -I$(srcdir)/src ## Specify the documentation files that are distributed. -# FIXME dist_doc_DATA = \ AUTHORS \ COPYING \ ChangeLog \ LICENCE \ - README - -# doc/pcre.txt \ -# doc/pcre-config.txt \ -# doc/pcregrep.txt \ -# doc/pcretest.txt \ -# NEWS + NEWS \ + README \ + doc/pcre2.txt \ + doc/pcre2-config.txt \ + doc/pcre2grep.txt \ + doc/pcre2test.txt # FIXME -#dist_html_DATA = \ -# doc/html/NON-AUTOTOOLS-BUILD.txt \ -# doc/html/README.txt \ -# doc/html/index.html \ -# doc/html/pcre-config.html \ +dist_html_DATA = \ + doc/html/NON-AUTOTOOLS-BUILD.txt \ + doc/html/README.txt \ + doc/html/index.html \ + doc/html/pcre2-config.html \ + doc/html/pcre2api.html \ + doc/html/pcre2callout.html \ + doc/html/pcre2demo.html \ + doc/html/pcre2test.html \ + doc/html/pcre2unicode.html + # doc/html/pcre.html \ -# doc/html/pcre16.html \ -# doc/html/pcre32.html \ # doc/html/pcre_assign_jit_stack.html \ # doc/html/pcre_compile.html \ # doc/html/pcre_compile2.html \ @@ -56,11 +58,8 @@ dist_doc_DATA = \ # doc/html/pcre_utf16_to_host_byte_order.html \ # doc/html/pcre_utf32_to_host_byte_order.html \ # doc/html/pcre_version.html \ -# doc/html/pcreapi.html \ # doc/html/pcrebuild.html \ -# doc/html/pcrecallout.html \ # doc/html/pcrecompat.html \ -# doc/html/pcredemo.html \ # doc/html/pcregrep.html \ # doc/html/pcrejit.html \ # doc/html/pcrelimits.html \ @@ -72,18 +71,16 @@ dist_doc_DATA = \ # doc/html/pcreprecompile.html \ # doc/html/pcresample.html \ # doc/html/pcrestack.html \ -# doc/html/pcresyntax.html \ -# doc/html/pcretest.html \ -# doc/html/pcreunicode.html +# doc/html/pcresyntax.html # FIXME dist_man_MANS = \ + doc/pcre2-config.1 \ doc/pcre2api.3 \ doc/pcre2callout.3 \ doc/pcre2test.1 \ doc/pcre2unicode.3 -# doc/pcre2-config.1 \ # doc/pcre2.3 \ # doc/pcre2-16.3 \ # doc/pcre2-32.3 \ @@ -168,7 +165,6 @@ EXTRA_DIST += \ EXTRA_DIST += \ doc/perltest.txt \ - NON-UNIX-USE \ NON-AUTOTOOLS-BUILD \ HACKING @@ -719,9 +715,9 @@ else coverage: @echo "Configuring with --enable-coverage is required to generate code coverage report." -DISTCLEANFILES += src/*.gcda src/*.gcno +DISTCLEANFILES += src/*.gcda src/*.gcno -distclean-local: +distclean-local: rm -rf $(PACKAGE)-$(VERSION)-coverage* endif # WITH_GCOV diff --git a/PrepareRelease b/PrepareRelease index c92d7f9..2b58a47 100755 --- a/PrepareRelease +++ b/PrepareRelease @@ -83,8 +83,7 @@ for file in pcre2api pcre2callout pcre2unicode ; do done # The three commands -for file in pcre2test ; do -# for file in pcre2test pcre2grep pcre-config ; do +for file in pcre2test pcre2grep pcre2-config ; do echo Making $file.txt nroff -c -man $file.1 >$file.rawtxt perl ../CleanTxt <$file.rawtxt >$file.txt @@ -133,7 +132,7 @@ echo "Making HTML documentation" /bin/rm html/* cp index.html.src html/index.html cp ../README html/README.txt -# cp ../NON-AUTOTOOLS-BUILD html/NON-AUTOTOOLS-BUILD.txt +cp ../NON-AUTOTOOLS-BUILD html/NON-AUTOTOOLS-BUILD.txt for file in *.1 ; do base=`basename $file .1` @@ -187,7 +186,6 @@ files="\ COPYING \ AUTHORS \ NEWS \ - NON-UNIX-USE \ NON-AUTOTOOLS-BUILD \ INSTALL \ 132html \ @@ -240,16 +238,6 @@ files="\ pcre32_utf32_utils.c \ pcre16_valid_utf16.c \ pcre32_valid_utf32.c \ - pcre_scanner.cc \ - pcre_scanner.h \ - pcre_scanner_unittest.cc \ - pcrecpp.cc \ - pcrecpp.h \ - pcrecpparg.h.in \ - pcrecpp_unittest.cc \ - pcre_stringpiece.cc \ - pcre_stringpiece.h.in \ - pcre_stringpiece_unittest.cc \ perltest.pl \ ucp.h \ makevp.bat \ diff --git a/doc/html/NON-AUTOTOOLS-BUILD.txt b/doc/html/NON-AUTOTOOLS-BUILD.txt new file mode 100644 index 0000000..6f36fe6 --- /dev/null +++ b/doc/html/NON-AUTOTOOLS-BUILD.txt @@ -0,0 +1,402 @@ +Building PCRE2 without using autotools +-------------------------------------- + +This document has been converted from the PCRE1 document, but is not yet +complete. I have removed a number of quite old sections about building in +various environments, as they applied only to PCRE1 and are probably out of +date. + + +This document contains the following sections: + + General + Generic instructions for the PCRE2 C library + Building for virtual Pascal + Stack size in Windows environments + Linking programs in Windows environments + Calling conventions in Windows environments + Comments about Win32 builds + Building PCRE2 on Windows with CMake + Testing with RunTest.bat + Building PCRE2 on native z/OS and z/VM + + +GENERAL + +I (Philip Hazel) have no experience of Windows or VMS sytems and how their +libraries work. The items in the PCRE2 distribution and Makefile that relate to +anything other than Linux systems are untested by me. + +The basic PCRE2 library consists entirely of code written in Standard C, and so +should compile successfully on any system that has a Standard C compiler and +library. + +The PCRE2 distribution includes a "configure" file for use by the +configure/make (autotools) build system, as found in many Unix-like +environments. The README file contains information about the options for +"configure". + +There is also support for CMake, which some users prefer, especially in Windows +environments, though it can also be run in Unix-like environments. See the +section entitled "Building PCRE2 on Windows with CMake" below. + +Versions of src/config.h and src/pcre2.h are distributed in the PCRE2 tarballs +under the names src/config.h.generic and src/pcre2.h.generic. These are +provided for those who build PCRE2 without using "configure" or CMake. If you +use "configure" or CMake, the .generic versions are not used. + + +GENERIC INSTRUCTIONS FOR THE PCRE2 C LIBRARY + +The following are generic instructions for building the PCRE2 C library "by +hand". If you are going to use CMake, this section does not apply to you; you +can skip ahead to the CMake section. + + (1) Copy or rename the file src/config.h.generic as src/config.h, and edit the + macro settings that it contains to whatever is appropriate for your + environment. In particular, you can alter the definition of the NEWLINE + macro to specify what character(s) you want to be interpreted as line + terminators. + + When you compile any of the PCRE2 modules, you must specify + -DHAVE_CONFIG_H to your compiler so that src/config.h is included in the + sources. + + An alternative approach is not to edit src/config.h, but to use -D on the + compiler command line to make any changes that you need to the + configuration options. In this case -DHAVE_CONFIG_H must not be set. + + NOTE: There have been occasions when the way in which certain parameters + in src/config.h are used has changed between releases. (In the + configure/make world, this is handled automatically.) When upgrading to a + new release, you are strongly advised to review src/config.h.generic + before re-using what you had previously. + + (2) Copy or rename the file src/pcre2.h.generic as src/pcre2.h. + + (3) EITHER: + Copy or rename file src/pcre2_chartables.c.dist as + src/pcre2_chartables.c. + + OR: + Compile src/dftables.c as a stand-alone program (using -DHAVE_CONFIG_H + if you have set up src/config.h), and then run it with the single + argument "src/pcre2_chartables.c". This generates a set of standard + character tables and writes them to that file. The tables are generated + using the default C locale for your system. If you want to use a locale + that is specified by LC_xxx environment variables, add the -L option to + the dftables command. You must use this method if you are building on a + system that uses EBCDIC code. + + The tables in src/pcre2_chartables.c are defaults. The caller of PCRE2 can + specify alternative tables at run time. + + (4) For an 8-bit library, compile the following source files, setting + -DPCRE2_CODE_UNIT_WIDTH=8 as a compiler option. Also set -DHAVE_CONFIG_H + if you have set up src/config.h with your configuration, or else use other + -D settings to change the configuration as required. + + pcre2_auto_possess.c + pcre2_chartables.c + pcre2_compile.c + pcre2_config.c + pcre2_context.c + pcre2_dfa_match.c + pcre2_error.c + pcre2_jit_compile.c + pcre2_jit_match.c + pcre2_jit_misc.c + pcre2_maketables.c + pcre2_match.c + pcre2_match_data.c + pcre2_newline.c + pcre2_ord2utf.c + pcre2_pattern_info.c + pcre2_string_utils.c + pcre2_study.c + pcre2_substring.c + pcre2_tables.c + pcre2_ucd.c + pcre2_valid_utf.c + pcre2_xclass.c + + Make sure that you include -I. in the compiler command (or equivalent for + an unusual compiler) so that all included PCRE2 header files are first + sought in the src directory under the current directory. Otherwise you run + the risk of picking up a previously-installed file from somewhere else. + + Note that you must compile pcre2_jit_xxx.c, even if you have not defined + SUPPORT_JIT in src/config.h, because when JIT support is not configured, + dummy functions are compiled. When JIT support IS configured, the JIT + sources #include other files from the sljit subdirectory, where there + should be 16 files, all of whose names begin with "sljit". + + (5) Now link all the compiled code into an object library in whichever form + your system keeps such libraries. This is the basic PCRE2 C 8-bit library. + If your system has static and shared libraries, you may have to do this + once for each type. + + (6) If you want to build a 16-bit library or 32-bit library (as well as, or + instead of the 8-bit library) just supply 16 or 32 as the value of + -DPCRE2_CODE_UNIT_WIDTH when you are compiling. + + (7) If you want to build the POSIX wrapper functions (which apply only to the + 8-bit library), ensure that you have the pcre2posix.h file and then + compile pcre2posix.c. Link the result (on its own) as the pcre2posix + library. + + (8) The pcre2test program can be linked with any combination of the 8-bit, + 16-bit and 32-bit libraries (depending on what you selected in + src/config.h). Compile pcre2test.c; don't forget -DHAVE_CONFIG_H if + necessary, but do NOT define PCRE2_CODE_UNIT_WIDTH. Then link with the + appropriate library/ies. If you compiled an 8-bit library, pcre2test also + needs the pcre2posix wrapper library. + + (9) Run pcre2test on the testinput files in the testdata directory, and check + that the output matches the corresponding testoutput files. There are + comments about what each test does in the section entitled "Testing PCRE2" + in the README file. If you compiled more than one of the 8-bit, 16-bit and + 32-bit libraries, you need to run pcre2test with the -16 option to do + 16-bit tests and with the -32 option to do 32-bit tests. + + Some tests are relevant only when certain build-time options are selected. + For example, test 4 is for Unicode support, and will not run if you have + built PCRE2 without it. See the comments at the start of each testinput + file. If you have a suitable Unix-like shell, the RunTest script will run + the appropriate tests for you. The command "RunTest list" will output a + list of all the tests. + + Note that the supplied files are in Unix format, with just LF characters + as line terminators. You may need to edit them to change this if your + system uses a different convention. + +(10) If you have built PCRE2 with SUPPORT_JIT, the JIT features can be tested + by running pcre2test with the -jit option. This is done automatically by + the RunTest script. You might also like to build and run the freestanding + JIT test program, pcre2_jit_test.c. + +(11) If you want to use the pcre2grep command, compile and link pcre2grep.c; it + uses only the basic 8-bit PCRE2 library (it does not need the pcre2posix + library). + + +BUILDING FOR VIRTUAL PASCAL + +FIXME FOR PCRE2 + +A script for building PCRE2 using Borland's C++ compiler for use with VPASCAL +was contributed by Alexander Tokarev. Stefan Weber updated the script and added +additional files. The following files in the distribution are for building +PCRE2 for use with VP/Borland: makevp_c.txt, makevp_l.txt, makevp.bat, +pcre2gexp.pas. + + +STACK SIZE IN WINDOWS ENVIRONMENTS + +The default processor stack size of 1Mb in some Windows environments is too +small for matching patterns that need much recursion. In particular, test 2 may +fail because of this. Normally, running out of stack causes a crash, but there +have been cases where the test program has just died silently. See your linker +documentation for how to increase stack size if you experience problems. The +Linux default of 8Mb is a reasonable choice for the stack, though even that can +be too small for some pattern/subject combinations. + +PCRE2 has a compile configuration option to disable the use of stack for +recursion so that heap is used instead. However, pattern matching is +significantly slower when this is done. There is more about stack usage in the +"pcre2stack" documentation. + + +LINKING PROGRAMS IN WINDOWS ENVIRONMENTS + +If you want to statically link a program against a PCRE2 library in the form of +a non-dll .a file, you must define PCRE2_STATIC before including src/pcre2.h. + + +CALLING CONVENTIONS IN WINDOWS ENVIRONMENTS + +It is possible to compile programs to use different calling conventions using +MSVC. Search the web for "calling conventions" for more information. To make it +easier to change the calling convention for the exported functions in the +PCRE2 library, the macro PCRE2_CALL_CONVENTION is present in all the external +definitions. It can be set externally when compiling (e.g. in CFLAGS). If it is +not set, it defaults to empty; the default calling convention is then used +(which is what is wanted most of the time). + + +COMMENTS ABOUT WIN32 BUILDS (see also "BUILDING PCRE2 ON WINDOWS WITH CMAKE") + +There are two ways of building PCRE2 using the "configure, make, make install" +paradigm on Windows systems: using MinGW or using Cygwin. These are not at all +the same thing; they are completely different from each other. There is also +support for building using CMake, which some users find a more straightforward +way of building PCRE2 under Windows. + +The MinGW home page (http://www.mingw.org/) says this: + + MinGW: A collection of freely available and freely distributable Windows + specific header files and import libraries combined with GNU toolsets that + allow one to produce native Windows programs that do not rely on any + 3rd-party C runtime DLLs. + +The Cygwin home page (http://www.cygwin.com/) says this: + + Cygwin is a Linux-like environment for Windows. It consists of two parts: + + . A DLL (cygwin1.dll) which acts as a Linux API emulation layer providing + substantial Linux API functionality + + . A collection of tools which provide Linux look and feel. + +On both MinGW and Cygwin, PCRE2 should build correctly using: + + ./configure && make && make install + +This should create two libraries called libpcre2-8 and libpcre2-posix. These +are independent libraries: when you link with libpcre2-posix you must also link +with libpcre2-8, which contains the basic functions. + +Using Cygwin's compiler generates libraries and executables that depend on +cygwin1.dll. If a library that is generated this way is distributed, +cygwin1.dll has to be distributed as well. Since cygwin1.dll is under the GPL +licence, this forces not only PCRE2 to be under the GPL, but also the entire +application. A distributor who wants to keep their own code proprietary must +purchase an appropriate Cygwin licence. + +MinGW has no such restrictions. The MinGW compiler generates a library or +executable that can run standalone on Windows without any third party dll or +licensing issues. + +But there is more complication: + +If a Cygwin user uses the -mno-cygwin Cygwin gcc flag, what that really does is +to tell Cygwin's gcc to use the MinGW gcc. Cygwin's gcc is only acting as a +front end to MinGW's gcc (if you install Cygwin's gcc, you get both Cygwin's +gcc and MinGW's gcc). So, a user can: + +. Build native binaries by using MinGW or by getting Cygwin and using + -mno-cygwin. + +. Build binaries that depend on cygwin1.dll by using Cygwin with the normal + compiler flags. + +The test files that are supplied with PCRE2 are in UNIX format, with LF +characters as line terminators. Unless your PCRE2 library uses a default +newline option that includes LF as a valid newline, it may be necessary to +change the line terminators in the test files to get some of the tests to work. + + +BUILDING PCRE2 ON WINDOWS WITH CMAKE + +CMake is an alternative configuration facility that can be used instead of +"configure". CMake creates project files (make files, solution files, etc.) +tailored to numerous development environments, including Visual Studio, +Borland, Msys, MinGW, NMake, and Unix. If possible, use short paths with no +spaces in the names for your CMake installation and your PCRE2 source and build +directories. + +The following instructions were contributed by a PCRE1 user, but they should +also work for PCRE2. If they are not followed exactly, errors may occur. In the +event that errors do occur, it is recommended that you delete the CMake cache +before attempting to repeat the CMake build process. In the CMake GUI, the +cache can be deleted by selecting "File > Delete Cache". + +1. Install the latest CMake version available from http://www.cmake.org/, and + ensure that cmake\bin is on your path. + +2. Unzip (retaining folder structure) the PCRE2 source tree into a source + directory such as C:\pcre2. You should ensure your local date and time + is not earlier than the file dates in your source dir if the release is + very new. + +3. Create a new, empty build directory, preferably a subdirectory of the + source dir. For example, C:\pcre2\pcre2-xx\build. + +4. Run cmake-gui from the Shell envirornment of your build tool, for example, + Msys for Msys/MinGW or Visual Studio Command Prompt for VC/VC++. Do not try + to start Cmake from the Windows Start menu, as this can lead to errors. + +5. Enter C:\pcre2\pcre2-xx and C:\pcre2\pcre2-xx\build for the source and + build directories, respectively. + +6. Hit the "Configure" button. + +7. Select the particular IDE / build tool that you are using (Visual + Studio, MSYS makefiles, MinGW makefiles, etc.) + +8. The GUI will then list several configuration options. This is where + you can enable Unicode support or other PCRE2 optional features. + +9. Hit "Configure" again. The adjacent "Generate" button should now be + active. + +10. Hit "Generate". + +11. The build directory should now contain a usable build system, be it a + solution file for Visual Studio, makefiles for MinGW, etc. Exit from + cmake-gui and use the generated build system with your compiler or IDE. + E.g., for MinGW you can run "make", or for Visual Studio, open the PCRE2 + solution, select the desired configuration (Debug, or Release, etc.) and + build the ALL_BUILD project. + +12. If during configuration with cmake-gui you've elected to build the test + programs, you can execute them by building the test project. E.g., for + MinGW: "make check"; for Visual Studio build the RUN_TESTS project. The + most recent build configuration is targeted by the tests. A summary of + test results is presented. Complete test output is subsequently + available for review in Testing\Temporary under your build dir. + + +TESTING WITH RUNTEST.BAT FIXME FIXME NOT YET TESTED/UPDATED FIXME + +If configured with CMake, building the test project ("make check" or building +ALL_TESTS in Visual Studio) creates (and runs) pcre2_test.bat (and depending +on your configuration options, possibly other test programs) in the build +directory. Pcre_test.bat runs RunTest.Bat with correct source and exe paths. + +For manual testing with RunTest.bat, provided the build dir is a subdirectory +of the source directory: Open command shell window. Chdir to the location +of your pcre2test.exe and pcre2grep.exe programs. Call RunTest.bat with +"..\RunTest.Bat" or "..\..\RunTest.bat" as appropriate. + +To run only a particular test with RunTest.Bat provide a test number argument. + +Otherwise: + +1. Copy RunTest.bat into the directory where pcre2test.exe and pcre2grep.exe + have been created. + +2. Edit RunTest.bat to indentify the full or relative location of + the pcre2 source (wherein which the testdata folder resides), e.g.: + + set srcdir=C:\pcre2\pcre2-10.00 + +3. In a Windows command environment, chdir to the location of your bat and + exe programs. + +4. Run RunTest.bat. Test outputs will automatically be compared to expected + results, and discrepancies will be identified in the console output. + +To independently test the just-in-time compiler, run pcre2_jit_test.exe. + + +BUILDING PCRE2 ON NATIVE Z/OS AND Z/VM + +z/OS and z/VM are operating systems for mainframe computers, produced by IBM. +The character code used is EBCDIC, not ASCII or Unicode. In z/OS, UNIX APIs and +applications can be supported through UNIX System Services, and in such an +environment PCRE2 can be built in the same way as in other systems. However, in +native z/OS (without UNIX System Services) and in z/VM, special ports are +required. For details, please see this web site: + + http://www.zaconsultants.net + +There is also a mirror here: + + http://www.vsoft-software.com/downloads.html + +The site currently has ports for PCRE1 releases, but PCRE2 should follow in due +course. + +========================== +Last Updated: 28 September 2014 diff --git a/doc/html/README.txt b/doc/html/README.txt index 7ad597a..95c8747 100644 --- a/doc/html/README.txt +++ b/doc/html/README.txt @@ -1 +1,832 @@ -This is a placeholder README file for a work in progress. +README file for PCRE2 (Perl-compatible regular expression library) +------------------------------------------------------------------ + +PCRE2 is a re-implementation of the original PCRE library with an entirely new +API. The latest release of PCRE2 is always available in three alternative +formats from: + +FIXME: THIS WILL NOT BE THE CASE UNTIL THERE IS A FORMAL RELEASE. + + ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre2/pcre2-xxx.tar.gz + ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre2/pcre2-xxx.tar.bz2 + ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre2/pcre2-xxx.zip + +There is a mailing list for discussion about the development of PCRE (both the +original and new APIs) 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 PCRE2 APIs + Documentation for PCRE2 + Contributions by users of PCRE2 + Building PCRE2 on non-Unix-like systems + Building PCRE2 without using autotools + Building PCRE2 using autotools + Retrieving configuration information + Shared libraries + Cross-compiling using autotools + Making new tarballs + Testing PCRE2 + Character tables + File manifest + + +The PCRE2 APIs +-------------- + +PCRE2 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. As this is a new API, +there as yet no C++ wrappers. + +The distribution does contain a set of C wrapper functions for the 8-bit +library that are based on the POSIX regular expression API (see the pcre2posix +man page). These end up in the library called libpcre2posix. Note that this +just provides a POSIX calling interface to PCRE2; the regular expressions +themselves still follow Perl syntax and semantics. The POSIX API is restricted, +and does not give full access to all of PCRE2's facilities. + +The header file for the POSIX-style functions is called pcre2posix.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 PCRE2 with +an existing program that uses the POSIX API, pcre2posix.h will have to be +renamed or pointed at by a link. + +If you are using the POSIX interface to PCRE2 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 PCRE2's libpcre2posix 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 PCRE2 with the addition of +-Dregcomp=PCRE2regcomp (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 PCRE2 +---------------------- + +If you install PCRE2 in the normal way on a Unix-like system, you will end up +with a set of man pages whose names all start with "pcre2". The one that is +just called "pcre2" lists all the others. In addition to these man pages, the +PCRE2 documentation is supplied in two other forms: + + 1. There are files called doc/pcre2.txt, doc/pcre2grep.txt, and + doc/pcre2test.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 pcre2demo.c and those that summarize individual functions. The + other two are the text forms of the section 1 man pages for the pcre2grep + and pcre2test commands. These text forms are provided for ease of scanning + with text editors or similar tools. They are installed in + /share/doc/pcre2, 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/pcre2/html. + + +Building PCRE2 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 PCRE2 using autotools in the same way as for +many Unix-like systems. + +PCRE2 can also be configured using CMake, which can be run in various ways +(command line, GUI, etc). This creates Makefiles, solution files, etc. The file +NON-AUTOTOOLS-BUILD has information about CMake. + +PCRE2 has been compiled on many different operating systems. It should be +straightforward to build PCRE2 on any system that has a Standard C compiler and +library, because it uses only Standard C functions. + + +Building PCRE2 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 PCRE2 without using autotools. + + +Building PCRE2 using autotools +----------------------------- + +The following instructions assume the use of the widely used "configure; make; +make install" (autotools) process. + +To build PCRE2 on system that supports autotools, first run the "configure" +command from the PCRE2 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 PCRE2 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 PCRE2 +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 PCRE2 source +into /source/pcre2/pcre2-xxx, but you want to build it in +/build/pcre2/pcre2-xxx: + +cd /build/pcre2/pcre2-xxx +/source/pcre2/pcre2-xxx/configure + +PCRE2 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 PCRE2 +library. They are also documented in the pcre2build 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 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. FIXME: NOT YET IMPLEMENTED. + +. When JIT support is enabled, pcre2grep automatically makes use of it, unless + you add --disable-pcre2grep-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, UTF-16 Unicode character strings in the 16-bit library, + and UTF-32 Unicode character strings in the 32-bit library, you must add + --enable-unicode to the "configure" command. Without it, the code for + handling UTF-8, UTF-16 and UTF-8 is not included. It is not possible to + configure one library with UTF support and the other without in the same + configuration. + + Even when --enable-unicode is included, the use of a UTF encoding still has + to be enabled by an option at run time. When PCRE2 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-unicode and + --enable-ebcdic at the same time. + + When --enable-unicode is specified, as well as supporting UTF strings, PCRE2 + includes support for the \P, \p, and \X sequences that recognize Unicode + character properties. However, only the basic two-letter properties such as + Lu are supported. + +. You can build PCRE2 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 PCRE2 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 PCRE2 considers + to be the end of a line (see above). However, the caller of PCRE2 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"). + +. PCRE2 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 + +. PCRE2 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 + pcre2_match() can supply their own value. There is more discussion on the + pcre2api 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 pcre2stack man page. + +. In the 8-bit library, the default maximum compiled pattern size is around + 64K. You can increase this by adding --with-link-size=3 to the "configure" + command. PCRE2 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 link size setting is ignored, as 4-byte offsets are always used. + +. You can build PCRE2 so that its internal match() function that is called from + pcre2_match() does not call itself recursively. Instead, it uses memory + blocks obtained from the heap to save data that would otherwise be saved on + the stack. To build PCRE2 like this, use + + --disable-stack-for-recursion + + on the "configure" command. PCRE2 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 pcre2_match() function; if JIT support is being + successfully used, it is not relevant. Equally, it does not apply to + pcre2_dfa_match(), which does not use deeply nested recursion. There is a + discussion about stack sizes in the pcre2stack man page. + +. For speed, PCRE2 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 pcre2_chartables.c. If you do + not specify this option, pcre2_chartables.c is created as a copy of + pcre2_chartables.c.dist. See "Character tables" below for further + information. + +. It is possible to compile PCRE2 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 PCRE2 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 + + PCRE2 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 PCRE2 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 PCRE2 for coverage reporting. + You can do this by setting the environment variable CCACHE_DISABLE=1 before + running "make" to build PCRE2. There is more information about coverage + reporting in the "pcre2build" documentation. + +. The pcre2grep program currently supports only 8-bit data files, and so + requires the 8-bit PCRE2 library. It is possible to compile pcre2grep to use + libz and/or libbz2, in order to read .gz and .bz2 files (respectively), by + specifying one or both of + + --enable-pcre2grep-libz + --enable-pcre2grep-libbz2 + + Of course, the relevant libraries must be installed on your system. + +. The default size (in bytes) of the internal buffer used by pcre2grep can be + set by, for example: + + --with-pcre2grep-bufsize=51200 + + The value must be a plain integer. The default is 20480. + +. It is possible to compile pcre2test so that it links with the libreadline + or libedit libraries, by specifying, respectively, + + --enable-pcre2test-libreadline or --enable-pcre2test-libedit + + If this is done, when pcre2test'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 + pcre2test 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 + pcre2test 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 +. src/config.h build-time configuration options for the library +. src/pcre2.h the public PCRE2 header file +. pcre2-config script that shows the building settings such as CFLAGS + that were set for "configure" +. libpcre2-8.pc ) +. libpcre2-16.pc ) data for the pkg-config command +. libpcre2-32.pc ) +. libpcre2-posix.pc ) +. libtool script that builds shared and/or static libraries + +Versions of config.h and pcre2.h are distributed in the src directory of PCRE2 +tarballs under the names config.h.generic and pcre2.h.generic. These are +provided for those who have to build PCRE2 without using "configure" or CMake. +If you use "configure" or CMake, the .generic versions are not used. + +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 whichever of the +libraries libpcre2-8, libpcre2-16 and libpcre2-32 are configured, and a test +program called pcre2test. If you enabled JIT support with --enable-jit, another +test program called pcre2_jit_test is built as well. FIXME: still to be +implemented. If the 8-bit library is built, libpcre2-posix and the pcre2grep +command are also built. + +The command "make check" runs all the appropriate tests. Details of the PCRE2 +tests are given below in a separate section of this document. + +You can use "make install" to install PCRE2 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): + pcre2test + pcre2grep (if 8-bit support is enabled) + pcre2-config + + Libraries (lib): + libpcre2-8 (if 8-bit support is enabled) + libpcre2-16 (if 16-bit support is enabled) + libpcre2-32 (if 32-bit support is enabled) + libpcre2-posix (if 8-bit support is enabled) + + Configuration information (lib/pkgconfig): + libpcre2-8.pc + libpcre2-16.pc + libpcre2-32.pc + libpcre2-posix.pc + + Header files (include): + pcre2.h + pcre2posix.h + + Man pages (share/man/man{1,3}): + pcre2grep.1 + pcre2test.1 + pcre2-config.1 + pcre2.3 + pcre2*.3 (lots more pages, all starting "pcre2") + + HTML documentation (share/doc/pcre2/html): + index.html + *.html (lots more pages, hyperlinked from index.html) + + Text file documentation (share/doc/pcre2): + AUTHORS + COPYING + ChangeLog + LICENCE + NEWS + README + pcre2.txt (a concatenation of the man(3) pages) + pcre2test.txt the pcre2test man page + pcre2grep.txt the pcre2grep man page + pcre2-config.txt the pcre2-config man page + +If you want to remove PCRE2 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 pcre2-config, which can be used to +recall information about the PCRE2 configuration and installation. For example: + + pcre2-config --version + +prints the version number, and + + pcre2-config --libs8 + +outputs information about where the 8-bit library is installed. This command +can be included in makefiles for programs that use PCRE2, saving the programmer +from having to remember too many details. Run pcre2-config with no arguments to +obtain a list of possible arguments. + +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 --libs libpcre2-16 + +The data is held in *.pc files that are installed in a directory called +/lib/pkgconfig. + + +Shared libraries +---------------- + +The default distribution builds PCRE2 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 pcre2test and pcre2grep 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, pcre2grep and pcre2test 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 PCRE2 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 PCRE2 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 pcre2_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, pcre2_chartables.c is +created by making a copy of pcre2_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 pcre2_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 pcre2_chartables.c.dist. +Then when you cross-compile PCRE2 this new version of the tables will be used. + + +Making new tarballs +------------------- + +The command "make dist" creates three PCRE2 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 PCRE2 +------------ + +To test the basic PCRE2 library on a Unix-like system, run the RunTest script. +There is another script called RunGrepTest that tests the options of the +pcre2grep command. When JIT support is enabled, another test program called +pcre2_jit_test is built. Both the scripts and all the program tests are run if +you obey "make check". For other environments, see the instructions in +NON-AUTOTOOLS-BUILD. + +The RunTest script runs the pcre2test 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 pcre2test. 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-unicode was +used. RunTest outputs a comment when it skips a test. + +Many of the tests that are not skipped are run twice if JIT support is +available. On the second run, JIT compilation is forced. 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 pcre2test 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 two tests can always be run, as they expect only plain text strings +(not UTF) and make no use of Unicode properties. 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 PCRE2 version. The second set of tests check +auxiliary functions, error detection, and run-time flags that are specific to +PCRE2, as well as the POSIX wrapper API. It also uses the debugging flags to +check some of the internals of pcre2_compile(). + +If you build PCRE2 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 PCRE2. + +The third set of tests checks pcre2_maketables(), the facility for building a +set of character tables for a specific locale and using them instead of the +default tables. The script uses the "locale" command to check for the +availability of the "fr_FR", "french", or "fr" locale, and uses the first one +that it finds. If the "locale" command fails, or if its output doesn't include +"fr_FR", "french", or "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 an error like this + + ** Failed to set locale "fr_FR" + +it means that the given locale is not available on your system, despite being +listed by "locale". This does not mean that PCRE2 is broken. There are three +alternative output files for the third test, because three different versions +of the French locale have been encountered. The test passes if its output +matches any one of them. + +The fourth and fifth tests check UTF and Unicode property support, the fourth +being compatible with the perltest.pl script, and the fifth checking +PCRE2-specific things. + +The sixth and seventh tests check the pcre2_dfa_match() alternative matching +function, in non-UTF mode and UTF-mode with Unicode property support, +respectively. + +The eighth 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 support is enabled. + +The ninth and tenth tests are run only in 8-bit mode, and the eleventh and +twelfth tests are run only in 16-bit and 32-bit modes. These are tests that +generate different output in 8-bit mode. Each pair are for general cases and +Unicode support, respectively. The thirteenth test checks the handling of +non-UTF characters greater than 255 by pcre2_dfa_match() in 16-bit and 32-bit +modes. + +The fourteenth test is run only when JIT support is not available, and the +fifteenth test is run only when JIT support is available. They test some +JIT-specific features such as information output from pcre2test about JIT +compilation. + +The sixteenth and seventeenth tests are run only in 8-bit mode. They check the +POSIX interface to the 8-bit library, withouth and with Unicode support, +respectively. + + +Character tables +---------------- + +For speed, PCRE2 uses four tables for manipulating and identifying characters +whose code point values are less than 256. By default, a set of tables that is +built into the library is used. The pcre2_maketables() function can be called +by an application to create a new set of tables in the current locale. This are +passed to PCRE2 by calling pcre2_set_character_tables() to put a pointer into a +compile context. + +The source file called pcre2_chartables.c contains the default set of tables. +By default, this is created as a copy of pcre2_chartables.c.dist, which +contains tables for ASCII coding. However, if --enable-rebuild-chartables is +specified for ./configure, a different version of pcre2_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 pcre2_chartables.c and +then re-building PCRE2. 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 pcre2_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 pcre2_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 PCRE2 to malfunction. + + +File manifest +------------- + +The distribution should contain the files listed below. + +(A) Source files for the PCRE2 library functions and their headers are found in + the src directory: + + src/dftables.c auxiliary program for building pcre2_chartables.c + when --enable-rebuild-chartables is specified + + src/pcre2_chartables.c.dist a default set of character tables that assume + ASCII coding; unless --enable-rebuild-chartables is + specified, used by copying to pcre2_chartables.c + + src/pcre2posix.c ) + src/pcre2_auto_possess.c ) + src/pcre2_compile.c ) + src/pcre2_config.c ) + src/pcre2_context.c ) + src/pcre2_dfa_match.c ) + src/pcre2_error.c ) + src/pcre2_exec.c ) + src/pcre2_jit_compile.c ) + src/pcre2_jit_match.c ) sources for the functions in the library, + src/pcre2_jit_misc.c ) and some internal functions that they use + src/pcre2_maketables.c ) + src/pcre2_match.c ) + src/pcre2_match_data.c ) + src/pcre2_newline.c ) + src/pcre2_ord2utf.c ) + src/pcre2_pattern_info.c ) + src/pcre2_string_utils.c ) + src/pcre2_study.c ) + src/pcre2_substring.c ) + src/pcre2_tables.c ) + src/pcre2_ucd.c ) + src/pcre2_valid_utf.c ) + src/pcre2_xclass.c ) + + src/pcre2_printint.c debugging function that is used by pcre2test, + + src/config.h.in template for config.h, when built by "configure" + src/pcre2.h.in template for pcre2.h when built by "configure" + src/pcre2posix.h header for the external POSIX wrapper API + src/pcre2_internal.h header for internal use + src/pcre2_intmodedep.h a mode-specific internal header + src/pcre2_ucp.h header for Unicode property handling + + sljit/* 16 files that make up the JIT compiler FIXME + +(B) Source files for programs that use PCRE2: + + src/pcre2demo.c simple demonstration of coding calls to PCRE2 + src/pcre2grep.c source of a grep utility that uses PCRE2 + src/pcre2test.c comprehensive test program + +(C) Auxiliary files: + + 132html script to turn "man" pages into HTML + AUTHORS information about the author of PCRE2 + 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 PCRE2 + INSTALL generic installation instructions + LICENCE conditions for the use of PCRE2 + 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-AUTOTOOLS-BUILD notes on building PCRE2 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 pcre2grep 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 PCRE2 + doc/*.1 man page sources for pcre2grep and pcre2test + doc/index.html.src the base HTML page + doc/html/* HTML documentation + doc/pcre2.txt plain text version of the man pages + doc/pcre2test.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 + libpcre2-8.pc.in template for libpcre2-8.pc for pkg-config + libpcre2-16.pc.in template for libpcre2-16.pc for pkg-config + libpcre2-32.pc.in template for libpcre2-32.pc for pkg-config + libpcre2posix.pc.in template for libpcre2posix.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 + pcre2-config.in source of script which retains PCRE2 information + pcre2_jit_test.c test program for the JIT compiler + testdata/testinput* test data for main library tests + testdata/testoutput* expected test results + testdata/grep* input and output for pcre2grep 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 FIXME FIXME + + makevp.bat + makevp_c.txt + makevp_l.txt + pcre2gexp.pas + +(F) Auxiliary files for building PCRE2 "by hand" + + pcre2.h.generic ) a version of the public PCRE2 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 FIXME + +Philip Hazel +Email local part: ph10 +Email domain: cam.ac.uk +Last updated: 27 October 2014 diff --git a/doc/html/pcre2-config.html b/doc/html/pcre2-config.html new file mode 100644 index 0000000..b71d760 --- /dev/null +++ b/doc/html/pcre2-config.html @@ -0,0 +1,102 @@ + + +pcre2-config specification + + +

pcre2-config man page

+

+Return to the PCRE2 index page. +

+

+This page is part of the PCRE2 HTML documentation. It was generated +automatically from the original man page. If there is any nonsense in it, +please consult the man page, in case the conversion went wrong. +
+

+
SYNOPSIS
+

+pcre2-config [--prefix] [--exec-prefix] [--version] + [--libs8] [--libs16] [--libs32] [--libs-posix] + [--cflags] [--cflags-posix] +

+
DESCRIPTION
+

+pcre2-config returns the configuration of the installed PCRE2 libraries +and the options required to compile a program to use them. Some of the options +apply only to the 8-bit, or 16-bit, or 32-bit libraries, respectively, and are +not available for libraries that have not been built. If an unavailable option +is encountered, the "usage" information is output. +

+
OPTIONS
+

+--prefix +Writes the directory prefix used in the PCRE2 installation for architecture +independent files (/usr on many systems, /usr/local on some +systems) to the standard output. +

+

+--exec-prefix +Writes the directory prefix used in the PCRE2 installation for architecture +dependent files (normally the same as --prefix) to the standard output. +

+

+--version +Writes the version number of the installed PCRE2 libraries to the standard +output. +

+

+--libs8 +Writes to the standard output the command line options required to link +with the 8-bit PCRE2 library (-lpcre2-8 on many systems). +

+

+--libs16 +Writes to the standard output the command line options required to link +with the 16-bit PCRE2 library (-lpcre2-16 on many systems). +

+

+--libs32 +Writes to the standard output the command line options required to link +with the 32-bit PCRE2 library (-lpcre2-32 on many systems). +

+

+--libs-posix +Writes to the standard output the command line options required to link with +PCRE2's POSIX API wrapper library (-lpcre2-posix -lpcre2-8 on many +systems). +

+

+--cflags +Writes to the standard output the command line options required to compile +files that use PCRE2 (this may include some -I options, but is blank on +many systems). +

+

+--cflags-posix +Writes to the standard output the command line options required to compile +files that use PCRE2's POSIX API wrapper library (this may include some +-I options, but is blank on many systems). +

+
SEE ALSO
+

+pcre2(3) +

+
AUTHOR
+

+This manual page was originally written by Mark Baker for the Debian GNU/Linux +system. It has been subsequently revised as a generic PCRE2 man page. +

+
REVISION
+

+Last updated: 28 September 2014 +
+

+Return to the PCRE2 index page. +

diff --git a/doc/html/pcre2.html b/doc/html/pcre2.html new file mode 100644 index 0000000..f8672b8 --- /dev/null +++ b/doc/html/pcre2.html @@ -0,0 +1,182 @@ + + +pcre2 specification + + +

pcre2 man page

+

+Return to the PCRE2 index page. +

+

+This page is part of the PCRE2 HTML documentation. It was generated +automatically from the original man page. If there is any nonsense in it, +please consult the man page, in case the conversion went wrong. +
+

+
INTRODUCTION
+

+PCRE2 is the name used for a revised API for the PCRE library, which is a set +of functions, written in C, that implement regular expression pattern matching +using the same syntax and semantics as Perl, with just a few differences. Some +features that appeared in Python and the original PCRE before they appeared in +Perl are also available using the Python syntax, there is some support for one +or two .NET and Oniguruma syntax items, and there are options for requesting +some minor changes that give better ECMAScript (aka JavaScript) compatibility. +

+

+The source code for PCRE2 can be compiled to support 8-bit, 16-bit, or 32-bit +code units, which means that up to three separate libraries may be installed. +The original work to extend PCRE to 16-bit and 32-bit code units was done by +Zoltan Herczeg and Christian Persch, respectively. In all three cases, strings +can be interpreted either as one character per code unit, or as UTF-encoded +Unicode, with support for Unicode general category properties. Unicode is +optional at build time, and must be enabled explicitly at run time. The version +of Unicode in use can be discovered by running +

+  pcre2test -C
+
+

+

+The three libraries contain identical sets of functions, with names ending in +_8, _16, or _32, respectively (for example, pcre2_compile_8()). However, +by defining PCRE2_CODE_UNIT_WIDTH to be 8, 16, or 32, a program that uses just +one code unit width can be written using generic names such as +pcre2_compile(), and the documentation is written assuming that this is +the case. +

+

+In addition to the Perl-compatible matching function, PCRE2 contains an +alternative function that matches the same compiled patterns in a different +way. In certain circumstances, the alternative function has some advantages. +For a discussion of the two matching algorithms, see the +pcre2matching +page. +

+

+Details of exactly which Perl regular expression features are and are not +supported by PCRE2 are given in separate documents. See the +pcre2pattern +and +pcre2compat +pages. There is a syntax summary in the +pcre2syntax +page. +

+

+Some features of PCRE2 can be included, excluded, or changed when the library +is built. The +pcre2_config() +function makes it possible for a client to discover which features are +available. The features themselves are described in the +pcre2build +page. Documentation about building PCRE2 for various operating systems can be +found in the +README +and +NON-AUTOTOOLS_BUILD +files in the source distribution. +

+

+The libraries contains a number of undocumented internal functions and data +tables that are used by more than one of the exported external functions, but +which are not intended for use by external callers. Their names all begin with +"_pcre2", which hopefully will not provoke any name clashes. In some +environments, it is possible to control which external symbols are exported +when a shared library is built, and in these cases the undocumented symbols are +not exported. +

+
SECURITY CONSIDERATIONS
+

+If you are using PCRE2 in a non-UTF application that permits users to supply +arbitrary patterns for compilation, you should be aware of a feature that +allows users to turn on UTF support from within a pattern, provided that PCRE2 +was built with Unicode support. For example, an 8-bit pattern that begins with +"(*UTF)" turns on UTF-8 mode, which interprets patterns and subjects as strings +of UTF-8 code units instead of individual 8-bit characters. This causes both +the pattern and any data against which it is matched to be checked for UTF-8 +validity. If the data string is very long, such a check might use sufficiently +many resources as to cause your application to lose performance. +

+

+One way of guarding against this possibility is to use the +pcre2_pattern_info() function to check the compiled pattern's options for +UTF. Alternatively, you can set the PCRE2_NEVER_UTF option at compile time. +This causes an compile time error if a pattern contains a UTF-setting sequence. +

+

+If your application is one that supports UTF, be aware that validity checking +can take time. If the same data string is to be matched many times, you can use +the PCRE2_NO_UTF_CHECK option for the second and subsequent matches to avoid +running redundant checks. +

+

+Another way that performance can be hit is by running a pattern that has a very +large search tree against a string that will never match. Nested unlimited +repeats in a pattern are a common example. PCRE2 provides some protection +against this: see the pcre2_set_match_limit() function in the +pcre2api +page. +

+
USER DOCUMENTATION
+

+The user documentation for PCRE2 comprises a number of different sections. In +the "man" format, each of these is a separate "man page". In the HTML format, +each is a separate page, linked from the index page. In the plain text format, +the descriptions of the pcre2grep and pcre2test programs are in +files called pcre2grep.txt and pcre2test.txt, respectively. The +remaining sections, except for the pcre2demo section (which is a program +listing), and the short pages for individual functions, are concatenated in +pcre2.txt, for ease of searching. The sections are as follows: +

+  pcre2              this document FIXME CHECK THIS LIST
+  pcre2-config       show PCRE2 installation configuration information
+  pcre2api           details of PCRE2's native C API
+  pcre2build         building PCRE2
+  pcre2callout       details of the callout feature
+  pcre2compat        discussion of Perl compatibility
+  pcre2demo          a demonstration C program that uses PCRE2
+  pcre2grep          description of the pcre2grep command (8-bit only)
+  pcre2jit           discussion of the just-in-time optimization support
+  pcre2limits        details of size and other limits
+  pcre2matching      discussion of the two matching algorithms
+  pcre2partial       details of the partial matching facility
+  pcre2pattern       syntax and semantics of supported regular expressions
+  pcre2perform       discussion of performance issues
+  pcre2posix         the POSIX-compatible C API for the 8-bit library
+  pcre2sample        discussion of the pcre2demo program
+  pcre2stack         discussion of stack usage
+  pcre2syntax        quick syntax reference
+  pcre2test          description of the pcre2test testing command
+  pcre2unicode       discussion of Unicode and UTF support
+
+In the "man" and HTML formats, there is also a short page for each C library +function, listing its arguments and results. +

+
AUTHOR
+

+Philip Hazel +
+University Computing Service +
+Cambridge CB2 3QH, England. +
+

+

+Putting an actual email address here is a spam magnet. If you want to email me, +use my two initials, followed by the two digits 10, at the domain cam.ac.uk. +

+
REVISION
+

+Last updated: 28 September 2014 +
+Copyright © 1997-2014 University of Cambridge. +
+

+Return to the PCRE2 index page. +

diff --git a/doc/html/pcre2grep.html b/doc/html/pcre2grep.html new file mode 100644 index 0000000..6528a38 --- /dev/null +++ b/doc/html/pcre2grep.html @@ -0,0 +1,759 @@ + + +pcre2grep specification + + +

pcre2grep man page

+

+Return to the PCRE2 index page. +

+

+This page is part of the PCRE2 HTML documentation. It was generated +automatically from the original man page. If there is any nonsense in it, +please consult the man page, in case the conversion went wrong. +
+

+
SYNOPSIS
+

+pcre2grep [options] [long options] [pattern] [path1 path2 ...] +

+
DESCRIPTION
+

+pcre2grep searches files for character patterns, in the same way as other +grep commands do, but it uses the PCRE2 regular expression library to support +patterns that are compatible with the regular expressions of Perl 5. See +pcre2syntax(3) +for a quick-reference summary of pattern syntax, or +pcre2pattern(3) +for a full description of the syntax and semantics of the regular expressions +that PCRE2 supports. +

+

+Patterns, whether supplied on the command line or in a separate file, are given +without delimiters. For example: +

+  pcre2grep Thursday /etc/motd
+
+If you attempt to use delimiters (for example, by surrounding a pattern with +slashes, as is common in Perl scripts), they are interpreted as part of the +pattern. Quotes can of course be used to delimit patterns on the command line +because they are interpreted by the shell, and indeed quotes are required if a +pattern contains white space or shell metacharacters. +

+

+The first argument that follows any option settings is treated as the single +pattern to be matched when neither -e nor -f is present. +Conversely, when one or both of these options are used to specify patterns, all +arguments are treated as path names. At least one of -e, -f, or an +argument pattern must be provided. +

+

+If no files are specified, pcre2grep reads the standard input. The +standard input can also be referenced by a name consisting of a single hyphen. +For example: +

+  pcre2grep some-pattern /file1 - /file3
+
+By default, each line that matches a pattern is copied to the standard +output, and if there is more than one file, the file name is output at the +start of each line, followed by a colon. However, there are options that can +change how pcre2grep behaves. In particular, the -M option makes it +possible to search for patterns that span line boundaries. What defines a line +boundary is controlled by the -N (--newline) option. +

+

+The amount of memory used for buffering files that are being scanned is +controlled by a parameter that can be set by the --buffer-size option. +The default value for this parameter is specified when pcre2grep is built, +with the default default being 20K. A block of memory three times this size is +used (to allow for buffering "before" and "after" lines). An error occurs if a +line overflows the buffer. +

+

+Patterns can be no longer than 8K or BUFSIZ bytes, whichever is the greater. +BUFSIZ is defined in <stdio.h>. When there is more than one pattern +(specified by the use of -e and/or -f), each pattern is applied to +each line in the order in which they are defined, except that all the -e +patterns are tried before the -f patterns. +

+

+By default, as soon as one pattern matches a line, no further patterns are +considered. However, if --colour (or --color) is used to colour the +matching substrings, or if --only-matching, --file-offsets, or +--line-offsets is used to output only the part of the line that matched +(either shown literally, or as an offset), scanning resumes immediately +following the match, so that further matches on the same line can be found. If +there are multiple patterns, they are all tried on the remainder of the line, +but patterns that follow the one that matched are not tried on the earlier part +of the line. +

+

+This behaviour means that the order in which multiple patterns are specified +can affect the output when one of the above options is used. This is no longer +the same behaviour as GNU grep, which now manages to display earlier matches +for later patterns (as long as there is no overlap). +

+

+Patterns that can match an empty string are accepted, but empty string +matches are never recognized. An example is the pattern "(super)?(man)?", in +which all components are optional. This pattern finds all occurrences of both +"super" and "man"; the output differs from matching with "super|man" when only +the matching substrings are being shown. +

+

+If the LC_ALL or LC_CTYPE environment variable is set, +pcre2grep uses the value to set a locale when calling the PCRE2 library. +The --locale option can be used to override this. +

+
SUPPORT FOR COMPRESSED FILES
+

+It is possible to compile pcre2grep so that it uses libz or +libbz2 to read files whose names end in .gz or .bz2, +respectively. You can find out whether your binary has support for one or both +of these file types by running it with the --help option. If the +appropriate support is not present, files are treated as plain text. The +standard input is always so treated. +

+
BINARY FILES
+

+By default, a file that contains a binary zero byte within the first 1024 bytes +is identified as a binary file, and is processed specially. (GNU grep also +identifies binary files in this manner.) See the --binary-files option +for a means of changing the way binary files are handled. +

+
OPTIONS
+

+The order in which some of the options appear can affect the output. For +example, both the -h and -l options affect the printing of file +names. Whichever comes later in the command line will be the one that takes +effect. Similarly, except where noted below, if an option is given twice, the +later setting is used. Numerical values for options may be followed by K or M, +to signify multiplication by 1024 or 1024*1024 respectively. +

+

+-- +This terminates the list of options. It is useful if the next item on the +command line starts with a hyphen but is not an option. This allows for the +processing of patterns and filenames that start with hyphens. +

+

+-A number, --after-context=number +Output number lines of context after each matching line. If filenames +and/or line numbers are being output, a hyphen separator is used instead of a +colon for the context lines. A line containing "--" is output between each +group of lines, unless they are in fact contiguous in the input file. The value +of number is expected to be relatively small. However, pcre2grep +guarantees to have up to 8K of following text available for context output. +

+

+-a, --text +Treat binary files as text. This is equivalent to +--binary-files=text. +

+

+-B number, --before-context=number +Output number lines of context before each matching line. If filenames +and/or line numbers are being output, a hyphen separator is used instead of a +colon for the context lines. A line containing "--" is output between each +group of lines, unless they are in fact contiguous in the input file. The value +of number is expected to be relatively small. However, pcre2grep +guarantees to have up to 8K of preceding text available for context output. +

+

+--binary-files=word +Specify how binary files are to be processed. If the word is "binary" (the +default), pattern matching is performed on binary files, but the only output is +"Binary file <name> matches" when a match succeeds. If the word is "text", +which is equivalent to the -a or --text option, binary files are +processed in the same way as any other file. In this case, when a match +succeeds, the output may be binary garbage, which can have nasty effects if +sent to a terminal. If the word is "without-match", which is equivalent to the +-I option, binary files are not processed at all; they are assumed not to +be of interest. +

+

+--buffer-size=number +Set the parameter that controls how much memory is used for buffering files +that are being scanned. +

+

+-C number, --context=number +Output number lines of context both before and after each matching line. +This is equivalent to setting both -A and -B to the same value. +

+

+-c, --count +Do not output individual lines from the files that are being scanned; instead +output the number of lines that would otherwise have been shown. If no lines +are selected, the number zero is output. If several files are are being +scanned, a count is output for each of them. However, if the +--files-with-matches option is also used, only those files whose counts +are greater than zero are listed. When -c is used, the -A, +-B, and -C options are ignored. +

+

+--colour, --color +If this option is given without any data, it is equivalent to "--colour=auto". +If data is required, it must be given in the same shell item, separated by an +equals sign. +

+

+--colour=value, --color=value +This option specifies under what circumstances the parts of a line that matched +a pattern should be coloured in the output. By default, the output is not +coloured. The value (which is optional, see above) may be "never", "always", or +"auto". In the latter case, colouring happens only if the standard output is +connected to a terminal. More resources are used when colouring is enabled, +because pcre2grep has to search for all possible matches in a line, not +just one, in order to colour them all. +
+
+The colour that is used can be specified by setting the environment variable +PCRE2GREP_COLOUR or PCRE2GREP_COLOR. The value of this variable should be a +string of two numbers, separated by a semicolon. They are copied directly into +the control string for setting colour on a terminal, so it is your +responsibility to ensure that they make sense. If neither of the environment +variables is set, the default is "1;31", which gives red. +

+

+-D action, --devices=action +If an input path is not a regular file or a directory, "action" specifies how +it is to be processed. Valid values are "read" (the default) or "skip" +(silently skip the path). +

+

+-d action, --directories=action +If an input path is a directory, "action" specifies how it is to be processed. +Valid values are "read" (the default in non-Windows environments, for +compatibility with GNU grep), "recurse" (equivalent to the -r option), or +"skip" (silently skip the path, the default in Windows environments). In the +"read" case, directories are read as if they were ordinary files. In some +operating systems the effect of reading a directory like this is an immediate +end-of-file; in others it may provoke an error. +

+

+-e pattern, --regex=pattern, --regexp=pattern +Specify a pattern to be matched. This option can be used multiple times in +order to specify several patterns. It can also be used as a way of specifying a +single pattern that starts with a hyphen. When -e is used, no argument +pattern is taken from the command line; all arguments are treated as file +names. There is no limit to the number of patterns. They are applied to each +line in the order in which they are defined until one matches. +
+
+If -f is used with -e, the command line patterns are matched first, +followed by the patterns from the file(s), independent of the order in which +these options are specified. Note that multiple use of -e is not the same +as a single pattern with alternatives. For example, X|Y finds the first +character in a line that is X or Y, whereas if the two patterns are given +separately, with X first, pcre2grep finds X if it is present, even if it +follows Y in the line. It finds Y only if there is no X in the line. This +matters only if you are using -o or --colo(u)r to show the part(s) +of the line that matched. +

+

+--exclude=pattern +Files (but not directories) whose names match the pattern are skipped without +being processed. This applies to all files, whether listed on the command line, +obtained from --file-list, or by scanning a directory. The pattern is a +PCRE2 regular expression, and is matched against the final component of the file +name, not the entire path. The -F, -w, and -x options do not +apply to this pattern. The option may be given any number of times in order to +specify multiple patterns. If a file name matches both an --include +and an --exclude pattern, it is excluded. There is no short form for this +option. +

+

+--exclude-from=filename +Treat each non-empty line of the file as the data for an --exclude +option. What constitutes a newline when reading the file is the operating +system's default. The --newline option has no effect on this option. This +option may be given more than once in order to specify a number of files to +read. +

+

+--exclude-dir=pattern +Directories whose names match the pattern are skipped without being processed, +whatever the setting of the --recursive option. This applies to all +directories, whether listed on the command line, obtained from +--file-list, or by scanning a parent directory. The pattern is a PCRE2 +regular expression, and is matched against the final component of the directory +name, not the entire path. The -F, -w, and -x options do not +apply to this pattern. The option may be given any number of times in order to +specify more than one pattern. If a directory matches both --include-dir +and --exclude-dir, it is excluded. There is no short form for this +option. +

+

+-F, --fixed-strings +Interpret each data-matching pattern as a list of fixed strings, separated by +newlines, instead of as a regular expression. What constitutes a newline for +this purpose is controlled by the --newline option. The -w (match +as a word) and -x (match whole line) options can be used with -F. +They apply to each of the fixed strings. A line is selected if any of the fixed +strings are found in it (subject to -w or -x, if present). This +option applies only to the patterns that are matched against the contents of +files; it does not apply to patterns specified by any of the --include or +--exclude options. +

+

+-f filename, --file=filename +Read patterns from the file, one per line, and match them against +each line of input. What constitutes a newline when reading the file is the +operating system's default. The --newline option has no effect on this +option. Trailing white space is removed from each line, and blank lines are +ignored. An empty file contains no patterns and therefore matches nothing. See +also the comments about multiple patterns versus a single pattern with +alternatives in the description of -e above. +
+
+If this option is given more than once, all the specified files are +read. A data line is output if any of the patterns match it. A filename can +be given as "-" to refer to the standard input. When -f is used, patterns +specified on the command line using -e may also be present; they are +tested before the file's patterns. However, no other pattern is taken from the +command line; all arguments are treated as the names of paths to be searched. +

+

+--file-list=filename +Read a list of files and/or directories that are to be scanned from the given +file, one per line. Trailing white space is removed from each line, and blank +lines are ignored. These paths are processed before any that are listed on the +command line. The filename can be given as "-" to refer to the standard input. +If --file and --file-list are both specified as "-", patterns are +read first. This is useful only when the standard input is a terminal, from +which further lines (the list of files) can be read after an end-of-file +indication. If this option is given more than once, all the specified files are +read. +

+

+--file-offsets +Instead of showing lines or parts of lines that match, show each match as an +offset from the start of the file and a length, separated by a comma. In this +mode, no context is shown. That is, the -A, -B, and -C +options are ignored. If there is more than one match in a line, each of them is +shown separately. This option is mutually exclusive with --line-offsets +and --only-matching. +

+

+-H, --with-filename +Force the inclusion of the filename at the start of output lines when searching +a single file. By default, the filename is not shown in this case. For matching +lines, the filename is followed by a colon; for context lines, a hyphen +separator is used. If a line number is also being output, it follows the file +name. +

+

+-h, --no-filename +Suppress the output filenames when searching multiple files. By default, +filenames are shown when multiple files are searched. For matching lines, the +filename is followed by a colon; for context lines, a hyphen separator is used. +If a line number is also being output, it follows the file name. +

+

+--help +Output a help message, giving brief details of the command options and file +type support, and then exit. Anything else on the command line is +ignored. +

+

+-I +Treat binary files as never matching. This is equivalent to +--binary-files=without-match. +

+

+-i, --ignore-case +Ignore upper/lower case distinctions during comparisons. +

+

+--include=pattern +If any --include patterns are specified, the only files that are +processed are those that match one of the patterns (and do not match an +--exclude pattern). This option does not affect directories, but it +applies to all files, whether listed on the command line, obtained from +--file-list, or by scanning a directory. The pattern is a PCRE2 regular +expression, and is matched against the final component of the file name, not +the entire path. The -F, -w, and -x options do not apply to +this pattern. The option may be given any number of times. If a file name +matches both an --include and an --exclude pattern, it is excluded. +There is no short form for this option. +

+

+--include-from=filename +Treat each non-empty line of the file as the data for an --include +option. What constitutes a newline for this purpose is the operating system's +default. The --newline option has no effect on this option. This option +may be given any number of times; all the files are read. +

+

+--include-dir=pattern +If any --include-dir patterns are specified, the only directories that +are processed are those that match one of the patterns (and do not match an +--exclude-dir pattern). This applies to all directories, whether listed +on the command line, obtained from --file-list, or by scanning a parent +directory. The pattern is a PCRE2 regular expression, and is matched against the +final component of the directory name, not the entire path. The -F, +-w, and -x options do not apply to this pattern. The option may be +given any number of times. If a directory matches both --include-dir and +--exclude-dir, it is excluded. There is no short form for this option. +

+

+-L, --files-without-match +Instead of outputting lines from the files, just output the names of the files +that do not contain any lines that would have been output. Each file name is +output once, on a separate line. +

+

+-l, --files-with-matches +Instead of outputting lines from the files, just output the names of the files +containing lines that would have been output. Each file name is output +once, on a separate line. Searching normally stops as soon as a matching line +is found in a file. However, if the -c (count) option is also used, +matching continues in order to obtain the correct count, and those files that +have at least one match are listed along with their counts. Using this option +with -c is a way of suppressing the listing of files with no matches. +

+

+--label=name +This option supplies a name to be used for the standard input when file names +are being output. If not supplied, "(standard input)" is used. There is no +short form for this option. +

+

+--line-buffered +When this option is given, input is read and processed line by line, and the +output is flushed after each write. By default, input is read in large chunks, +unless pcre2grep can determine that it is reading from a terminal (which +is currently possible only in Unix-like environments). Output to terminal is +normally automatically flushed by the operating system. This option can be +useful when the input or output is attached to a pipe and you do not want +pcre2grep to buffer up large amounts of data. However, its use will affect +performance, and the -M (multiline) option ceases to work. +

+

+--line-offsets +Instead of showing lines or parts of lines that match, show each match as a +line number, the offset from the start of the line, and a length. The line +number is terminated by a colon (as usual; see the -n option), and the +offset and length are separated by a comma. In this mode, no context is shown. +That is, the -A, -B, and -C options are ignored. If there is +more than one match in a line, each of them is shown separately. This option is +mutually exclusive with --file-offsets and --only-matching. +

+

+--locale=locale-name +This option specifies a locale to be used for pattern matching. It overrides +the value in the LC_ALL or LC_CTYPE environment variables. If no +locale is specified, the PCRE2 library's default (usually the "C" locale) is +used. There is no short form for this option. +

+

+--match-limit=number +Processing some regular expression patterns can require a very large amount of +memory, leading in some cases to a program crash if not enough is available. +Other patterns may take a very long time to search for all possible matching +strings. The pcre2_exec() function that is called by pcre2grep to do +the matching has two parameters that can limit the resources that it uses. +
+
+The --match-limit option provides a means of limiting resource usage +when processing patterns that are not going to match, but which have a very +large number of possibilities in their search trees. The classic example is a +pattern that uses nested unlimited repeats. Internally, PCRE2 uses a function +called match() which it calls repeatedly (sometimes recursively). The +limit set by --match-limit is imposed on the number of times this +function is called during a match, which has the effect of limiting the amount +of backtracking that can take place. +
+
+The --recursion-limit option is similar to --match-limit, but +instead of limiting the total number of times that match() is called, it +limits the depth of recursive calls, which in turn limits the amount of memory +that can be used. The recursion depth is a smaller number than the total number +of calls, because not all calls to match() are recursive. This limit is +of use only if it is set smaller than --match-limit. +
+
+There are no short forms for these options. The default settings are specified +when the PCRE2 library is compiled, with the default default being 10 million. +

+

+-M, --multiline +Allow patterns to match more than one line. When this option is given, patterns +may usefully contain literal newline characters and internal occurrences of ^ +and $ characters. The output for a successful match may consist of more than +one line, the last of which is the one in which the match ended. If the matched +string ends with a newline sequence the output ends at the end of that line. +
+
+When this option is set, the PCRE2 library is called in "multiline" mode. +There is a limit to the number of lines that can be matched, imposed by the way +that pcre2grep buffers the input file as it scans it. However, +pcre2grep ensures that at least 8K characters or the rest of the document +(whichever is the shorter) are available for forward matching, and similarly +the previous 8K characters (or all the previous characters, if fewer than 8K) +are guaranteed to be available for lookbehind assertions. This option does not +work when input is read line by line (see \fP--line-buffered\fP.) +

+

+-N newline-type, --newline=newline-type +The PCRE2 library supports five different conventions for indicating +the ends of lines. They are the single-character sequences CR (carriage return) +and LF (linefeed), the two-character sequence CRLF, an "anycrlf" convention, +which recognizes any of the preceding three types, and an "any" convention, in +which any Unicode line ending sequence is assumed to end a line. The Unicode +sequences are the three just mentioned, plus VT (vertical tab, U+000B), FF +(form feed, U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and +PS (paragraph separator, U+2029). +
+
+When the PCRE2 library is built, a default line-ending sequence is specified. +This is normally the standard sequence for the operating system. Unless +otherwise specified by this option, pcre2grep uses the library's default. +The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This +makes it possible to use pcre2grep to scan files that have come from other +environments without having to modify their line endings. If the data that is +being scanned does not agree with the convention set by this option, +pcre2grep may behave in strange ways. Note that this option does not +apply to files specified by the -f, --exclude-from, or +--include-from options, which are expected to use the operating system's +standard newline sequence. +

+

+-n, --line-number +Precede each output line by its line number in the file, followed by a colon +for matching lines or a hyphen for context lines. If the filename is also being +output, it precedes the line number. This option is forced if +--line-offsets is used. +

+

+--no-jit +If the PCRE2 library is built with support for just-in-time compiling (which +speeds up matching), pcre2grep automatically makes use of this, unless it +was explicitly disabled at build time. This option can be used to disable the +use of JIT at run time. It is provided for testing and working round problems. +It should never be needed in normal use. +

+

+-o, --only-matching +Show only the part of the line that matched a pattern instead of the whole +line. In this mode, no context is shown. That is, the -A, -B, and +-C options are ignored. If there is more than one match in a line, each +of them is shown separately. If -o is combined with -v (invert the +sense of the match to find non-matching lines), no output is generated, but the +return code is set appropriately. If the matched portion of the line is empty, +nothing is output unless the file name or line number are being printed, in +which case they are shown on an otherwise empty line. This option is mutually +exclusive with --file-offsets and --line-offsets. +

+

+-onumber, --only-matching=number +Show only the part of the line that matched the capturing parentheses of the +given number. Up to 32 capturing parentheses are supported, and -o0 is +equivalent to -o without a number. Because these options can be given +without an argument (see above), if an argument is present, it must be given in +the same shell item, for example, -o3 or --only-matching=2. The comments given +for the non-argument case above also apply to this case. If the specified +capturing parentheses do not exist in the pattern, or were not set in the +match, nothing is output unless the file name or line number are being printed. +
+
+If this option is given multiple times, multiple substrings are output, in the +order the options are given. For example, -o3 -o1 -o3 causes the substrings +matched by capturing parentheses 3 and 1 and then 3 again to be output. By +default, there is no separator (but see the next option). +

+

+--om-separator=text +Specify a separating string for multiple occurrences of -o. The default +is an empty string. Separating strings are never coloured. +

+

+-q, --quiet +Work quietly, that is, display nothing except error messages. The exit +status indicates whether or not any matches were found. +

+

+-r, --recursive +If any given path is a directory, recursively scan the files it contains, +taking note of any --include and --exclude settings. By default, a +directory is read as a normal file; in some operating systems this gives an +immediate end-of-file. This option is a shorthand for setting the -d +option to "recurse". +

+

+--recursion-limit=number +See --match-limit above. +

+

+-s, --no-messages +Suppress error messages about non-existent or unreadable files. Such files are +quietly skipped. However, the return code is still 2, even if matches were +found in other files. +

+

+-u, --utf-8 +Operate in UTF-8 mode. This option is available only if PCRE2 has been compiled +with UTF-8 support. All patterns (including those for any --exclude and +--include options) and all subject lines that are scanned must be valid +strings of UTF-8 characters. +

+

+-V, --version +Write the version numbers of pcre2grep and the PCRE2 library to the +standard output and then exit. Anything else on the command line is +ignored. +

+

+-v, --invert-match +Invert the sense of the match, so that lines which do not match any of +the patterns are the ones that are found. +

+

+-w, --word-regex, --word-regexp +Force the patterns to match only whole words. This is equivalent to having \b +at the start and end of the pattern. This option applies only to the patterns +that are matched against the contents of files; it does not apply to patterns +specified by any of the --include or --exclude options. +

+

+-x, --line-regex, --line-regexp +Force the patterns to be anchored (each must start matching at the beginning of +a line) and in addition, require them to match entire lines. This is equivalent +to having ^ and $ characters at the start and end of each alternative branch in +every pattern. This option applies only to the patterns that are matched +against the contents of files; it does not apply to patterns specified by any +of the --include or --exclude options. +

+
ENVIRONMENT VARIABLES
+

+The environment variables LC_ALL and LC_CTYPE are examined, in that +order, for a locale. The first one that is set is used. This can be overridden +by the --locale option. If no locale is set, the PCRE2 library's default +(usually the "C" locale) is used. +

+
NEWLINES
+

+The -N (--newline) option allows pcre2grep to scan files with +different newline conventions from the default. Any parts of the input files +that are written to the standard output are copied identically, with whatever +newline sequences they have in the input. However, the setting of this option +does not affect the interpretation of files specified by the -f, +--exclude-from, or --include-from options, which are assumed to use +the operating system's standard newline sequence, nor does it affect the way in +which pcre2grep writes informational messages to the standard error and +output streams. For these it uses the string "\n" to indicate newlines, +relying on the C I/O library to convert this to an appropriate sequence. +

+
OPTIONS COMPATIBILITY
+

+Many of the short and long forms of pcre2grep's options are the same +as in the GNU grep program. Any long option of the form +--xxx-regexp (GNU terminology) is also available as --xxx-regex +(PCRE2 terminology). However, the --file-list, --file-offsets, +--include-dir, --line-offsets, --locale, --match-limit, +-M, --multiline, -N, --newline, --om-separator, +--recursion-limit, -u, and --utf-8 options are specific to +pcre2grep, as is the use of the --only-matching option with a +capturing parentheses number. +

+

+Although most of the common options work the same way, a few are different in +pcre2grep. For example, the --include option's argument is a glob +for GNU grep, but a regular expression for pcre2grep. If both the +-c and -l options are given, GNU grep lists only file names, +without counts, but pcre2grep gives the counts. +

+
OPTIONS WITH DATA
+

+There are four different ways in which an option with data can be specified. +If a short form option is used, the data may follow immediately, or (with one +exception) in the next command line item. For example: +

+  -f/some/file
+  -f /some/file
+
+The exception is the -o option, which may appear with or without data. +Because of this, if data is present, it must follow immediately in the same +item, for example -o3. +

+

+If a long form option is used, the data may appear in the same command line +item, separated by an equals character, or (with two exceptions) it may appear +in the next command line item. For example: +

+  --file=/some/file
+  --file /some/file
+
+Note, however, that if you want to supply a file name beginning with ~ as data +in a shell command, and have the shell expand ~ to a home directory, you must +separate the file name from the option, because the shell does not treat ~ +specially unless it is at the start of an item. +

+

+The exceptions to the above are the --colour (or --color) and +--only-matching options, for which the data is optional. If one of these +options does have data, it must be given in the first form, using an equals +character. Otherwise pcre2grep will assume that it has no data. +

+
MATCHING ERRORS
+

+It is possible to supply a regular expression that takes a very long time to +fail to match certain lines. Such patterns normally involve nested indefinite +repeats, for example: (a+)*\d when matched against a line of a's with no final +digit. The PCRE2 matching function has a resource limit that causes it to abort +in these circumstances. If this happens, pcre2grep outputs an error +message and the line that caused the problem to the standard error stream. If +there are more than 20 such errors, pcre2grep gives up. +

+

+The --match-limit option of pcre2grep can be used to set the overall +resource limit; there is a second option called --recursion-limit that +sets a limit on the amount of memory (usually stack) that is used (see the +discussion of these options above). +

+
DIAGNOSTICS
+

+Exit status is 0 if any matches were found, 1 if no matches were found, and 2 +for syntax errors, overlong lines, non-existent or inaccessible files (even if +matches were found in other files) or too many matching errors. Using the +-s option to suppress error messages about inaccessible files does not +affect the return code. +

+
SEE ALSO
+

+pcre2pattern(3), pcre2syntax(3), pcre2test(1). +

+
AUTHOR
+

+Philip Hazel +
+University Computing Service +
+Cambridge CB2 3QH, England. +
+

+
REVISION
+

+Last updated: 28 September 2014 +
+Copyright © 1997-2014 University of Cambridge. +
+

+Return to the PCRE2 index page. +

diff --git a/doc/pcre2-config.1 b/doc/pcre2-config.1 new file mode 100644 index 0000000..7fa0a09 --- /dev/null +++ b/doc/pcre2-config.1 @@ -0,0 +1,86 @@ +.TH PCRE2-CONFIG 1 "28 September 2014" "PCRE2 10.00" +.SH NAME +pcre2-config - program to return PCRE2 configuration +.SH SYNOPSIS +.rs +.sp +.nf +.B pcre2-config [--prefix] [--exec-prefix] [--version] +.B " [--libs8] [--libs16] [--libs32] [--libs-posix]" +.B " [--cflags] [--cflags-posix]" +.fi +. +. +.SH DESCRIPTION +.rs +.sp +\fBpcre2-config\fP returns the configuration of the installed PCRE2 libraries +and the options required to compile a program to use them. Some of the options +apply only to the 8-bit, or 16-bit, or 32-bit libraries, respectively, and are +not available for libraries that have not been built. If an unavailable option +is encountered, the "usage" information is output. +. +. +.SH OPTIONS +.rs +.TP 10 +\fB--prefix\fP +Writes the directory prefix used in the PCRE2 installation for architecture +independent files (\fI/usr\fP on many systems, \fI/usr/local\fP on some +systems) to the standard output. +.TP 10 +\fB--exec-prefix\fP +Writes the directory prefix used in the PCRE2 installation for architecture +dependent files (normally the same as \fB--prefix\fP) to the standard output. +.TP 10 +\fB--version\fP +Writes the version number of the installed PCRE2 libraries to the standard +output. +.TP 10 +\fB--libs8\fP +Writes to the standard output the command line options required to link +with the 8-bit PCRE2 library (\fB-lpcre2-8\fP on many systems). +.TP 10 +\fB--libs16\fP +Writes to the standard output the command line options required to link +with the 16-bit PCRE2 library (\fB-lpcre2-16\fP on many systems). +.TP 10 +\fB--libs32\fP +Writes to the standard output the command line options required to link +with the 32-bit PCRE2 library (\fB-lpcre2-32\fP on many systems). +.TP 10 +\fB--libs-posix\fP +Writes to the standard output the command line options required to link with +PCRE2's POSIX API wrapper library (\fB-lpcre2-posix\fP \fB-lpcre2-8\fP on many +systems). +.TP 10 +\fB--cflags\fP +Writes to the standard output the command line options required to compile +files that use PCRE2 (this may include some \fB-I\fP options, but is blank on +many systems). +.TP 10 +\fB--cflags-posix\fP +Writes to the standard output the command line options required to compile +files that use PCRE2's POSIX API wrapper library (this may include some +\fB-I\fP options, but is blank on many systems). +. +. +.SH "SEE ALSO" +.rs +.sp +\fBpcre2(3)\fP +. +. +.SH AUTHOR +.rs +.sp +This manual page was originally written by Mark Baker for the Debian GNU/Linux +system. It has been subsequently revised as a generic PCRE2 man page. +. +. +.SH REVISION +.rs +.sp +.nf +Last updated: 28 September 2014 +.fi diff --git a/doc/pcre2-config.txt b/doc/pcre2-config.txt new file mode 100644 index 0000000..8ddea2a --- /dev/null +++ b/doc/pcre2-config.txt @@ -0,0 +1,81 @@ +PCRE2-CONFIG(1) General Commands Manual PCRE2-CONFIG(1) + + + +NAME + pcre2-config - program to return PCRE2 configuration + +SYNOPSIS + + pcre2-config [--prefix] [--exec-prefix] [--version] + [--libs8] [--libs16] [--libs32] [--libs-posix] + [--cflags] [--cflags-posix] + + +DESCRIPTION + + pcre2-config returns the configuration of the installed PCRE2 libraries + and the options required to compile a program to use them. Some of the + options apply only to the 8-bit, or 16-bit, or 32-bit libraries, + respectively, and are not available for libraries that have not been + built. If an unavailable option is encountered, the "usage" information + is output. + + +OPTIONS + + --prefix Writes the directory prefix used in the PCRE2 installation + for architecture independent files (/usr on many systems, + /usr/local on some systems) to the standard output. + + --exec-prefix + Writes the directory prefix used in the PCRE2 installation + for architecture dependent files (normally the same as --pre- + fix) to the standard output. + + --version Writes the version number of the installed PCRE2 libraries to + the standard output. + + --libs8 Writes to the standard output the command line options + required to link with the 8-bit PCRE2 library (-lpcre2-8 on + many systems). + + --libs16 Writes to the standard output the command line options + required to link with the 16-bit PCRE2 library (-lpcre2-16 on + many systems). + + --libs32 Writes to the standard output the command line options + required to link with the 32-bit PCRE2 library (-lpcre2-32 on + many systems). + + --libs-posix + Writes to the standard output the command line options + required to link with PCRE2's POSIX API wrapper library + (-lpcre2-posix -lpcre2-8 on many systems). + + --cflags Writes to the standard output the command line options + required to compile files that use PCRE2 (this may include + some -I options, but is blank on many systems). + + --cflags-posix + Writes to the standard output the command line options + required to compile files that use PCRE2's POSIX API wrapper + library (this may include some -I options, but is blank on + many systems). + + +SEE ALSO + + pcre2(3) + + +AUTHOR + + This manual page was originally written by Mark Baker for the Debian + GNU/Linux system. It has been subsequently revised as a generic PCRE2 + man page. + + +REVISION + + Last updated: 28 September 2014 diff --git a/doc/pcre2.3 b/doc/pcre2.3 new file mode 100644 index 0000000..aaa71d3 --- /dev/null +++ b/doc/pcre2.3 @@ -0,0 +1,180 @@ +.TH PCRE2 3 "28 September 2014" "PCRE2 10.00" +.SH NAME +PCRE2 - Perl-compatible regular expressions (revised API) +.SH INTRODUCTION +.rs +.sp +PCRE2 is the name used for a revised API for the PCRE library, which is a set +of functions, written in C, that implement regular expression pattern matching +using the same syntax and semantics as Perl, with just a few differences. Some +features that appeared in Python and the original PCRE before they appeared in +Perl are also available using the Python syntax, there is some support for one +or two .NET and Oniguruma syntax items, and there are options for requesting +some minor changes that give better ECMAScript (aka JavaScript) compatibility. +.P +The source code for PCRE2 can be compiled to support 8-bit, 16-bit, or 32-bit +code units, which means that up to three separate libraries may be installed. +The original work to extend PCRE to 16-bit and 32-bit code units was done by +Zoltan Herczeg and Christian Persch, respectively. In all three cases, strings +can be interpreted either as one character per code unit, or as UTF-encoded +Unicode, with support for Unicode general category properties. Unicode is +optional at build time, and must be enabled explicitly at run time. The version +of Unicode in use can be discovered by running +.sp + pcre2test -C +.P +The three libraries contain identical sets of functions, with names ending in +_8, _16, or _32, respectively (for example, \fBpcre2_compile_8()\fP). However, +by defining PCRE2_CODE_UNIT_WIDTH to be 8, 16, or 32, a program that uses just +one code unit width can be written using generic names such as +\fBpcre2_compile()\fP, and the documentation is written assuming that this is +the case. +.P +In addition to the Perl-compatible matching function, PCRE2 contains an +alternative function that matches the same compiled patterns in a different +way. In certain circumstances, the alternative function has some advantages. +For a discussion of the two matching algorithms, see the +.\" HREF +\fBpcre2matching\fP +.\" +page. +.P +Details of exactly which Perl regular expression features are and are not +supported by PCRE2 are given in separate documents. See the +.\" HREF +\fBpcre2pattern\fP +.\" +and +.\" HREF +\fBpcre2compat\fP +.\" +pages. There is a syntax summary in the +.\" HREF +\fBpcre2syntax\fP +.\" +page. +.P +Some features of PCRE2 can be included, excluded, or changed when the library +is built. The +.\" HREF +\fBpcre2_config()\fP +.\" +function makes it possible for a client to discover which features are +available. The features themselves are described in the +.\" HREF +\fBpcre2build\fP +.\" +page. Documentation about building PCRE2 for various operating systems can be +found in the +.\" HTML +.\" +\fBREADME\fP +.\" +and +.\" HTML +.\" +\fBNON-AUTOTOOLS_BUILD\fP +.\" +files in the source distribution. +.P +The libraries contains a number of undocumented internal functions and data +tables that are used by more than one of the exported external functions, but +which are not intended for use by external callers. Their names all begin with +"_pcre2", which hopefully will not provoke any name clashes. In some +environments, it is possible to control which external symbols are exported +when a shared library is built, and in these cases the undocumented symbols are +not exported. +. +. +.SH "SECURITY CONSIDERATIONS" +.rs +.sp +If you are using PCRE2 in a non-UTF application that permits users to supply +arbitrary patterns for compilation, you should be aware of a feature that +allows users to turn on UTF support from within a pattern, provided that PCRE2 +was built with Unicode support. For example, an 8-bit pattern that begins with +"(*UTF)" turns on UTF-8 mode, which interprets patterns and subjects as strings +of UTF-8 code units instead of individual 8-bit characters. This causes both +the pattern and any data against which it is matched to be checked for UTF-8 +validity. If the data string is very long, such a check might use sufficiently +many resources as to cause your application to lose performance. +.P +One way of guarding against this possibility is to use the +\fBpcre2_pattern_info()\fP function to check the compiled pattern's options for +UTF. Alternatively, you can set the PCRE2_NEVER_UTF option at compile time. +This causes an compile time error if a pattern contains a UTF-setting sequence. +.P +If your application is one that supports UTF, be aware that validity checking +can take time. If the same data string is to be matched many times, you can use +the PCRE2_NO_UTF_CHECK option for the second and subsequent matches to avoid +running redundant checks. +.P +Another way that performance can be hit is by running a pattern that has a very +large search tree against a string that will never match. Nested unlimited +repeats in a pattern are a common example. PCRE2 provides some protection +against this: see the \fBpcre2_set_match_limit()\fP function in the +.\" HREF +\fBpcre2api\fP +.\" +page. +. +. +.SH "USER DOCUMENTATION" +.rs +.sp +The user documentation for PCRE2 comprises a number of different sections. In +the "man" format, each of these is a separate "man page". In the HTML format, +each is a separate page, linked from the index page. In the plain text format, +the descriptions of the \fBpcre2grep\fP and \fBpcre2test\fP programs are in +files called \fBpcre2grep.txt\fP and \fBpcre2test.txt\fP, respectively. The +remaining sections, except for the \fBpcre2demo\fP section (which is a program +listing), and the short pages for individual functions, are concatenated in +\fBpcre2.txt\fP, for ease of searching. The sections are as follows: +.sp + pcre2 this document FIXME CHECK THIS LIST + pcre2-config show PCRE2 installation configuration information + pcre2api details of PCRE2's native C API + pcre2build building PCRE2 + pcre2callout details of the callout feature + pcre2compat discussion of Perl compatibility + pcre2demo a demonstration C program that uses PCRE2 + pcre2grep description of the \fBpcre2grep\fP command (8-bit only) + pcre2jit discussion of the just-in-time optimization support + pcre2limits details of size and other limits + pcre2matching discussion of the two matching algorithms + pcre2partial details of the partial matching facility +.\" JOIN + pcre2pattern syntax and semantics of supported + regular expressions + pcre2perform discussion of performance issues + pcre2posix the POSIX-compatible C API for the 8-bit library + pcre2sample discussion of the pcre2demo program + pcre2stack discussion of stack usage + pcre2syntax quick syntax reference + pcre2test description of the \fBpcre2test\fP testing command + pcre2unicode discussion of Unicode and UTF support +.sp +In the "man" and HTML formats, there is also a short page for each C library +function, listing its arguments and results. +. +. +.SH AUTHOR +.rs +.sp +.nf +Philip Hazel +University Computing Service +Cambridge CB2 3QH, England. +.fi +.P +Putting an actual email address here is a spam magnet. If you want to email me, +use my two initials, followed by the two digits 10, at the domain cam.ac.uk. +. +. +.SH REVISION +.rs +.sp +.nf +Last updated: 28 September 2014 +Copyright (c) 1997-2014 University of Cambridge. +.fi diff --git a/doc/pcre2build.3 b/doc/pcre2build.3 new file mode 100644 index 0000000..2146777 --- /dev/null +++ b/doc/pcre2build.3 @@ -0,0 +1,490 @@ +.TH PCRE2BUILD 3 "28 Sepember 2014" "PCRE2 10.00" +.SH NAME +PCRE2 - Perl-compatible regular expressions (revised API) +. +. +.SH "BUILDING PCRE2" +.rs +.sp +PCRE2 is distributed with a \fBconfigure\fP script that can be used to build +the library in Unix-like environments using the applications known as +Autotools. Also in the distribution are files to support building using +\fBCMake\fP instead of \fBconfigure\fP. The text file +.\" HTML +.\" +\fBREADME\fP +.\" +contains general information about building with Autotools (some of which is +repeated below), and also has some comments about building on various operating +systems. There is a lot more information about building PCRE2 without using +Autotools (including information about using \fBCMake\fP and building "by +hand") in the text file called +.\" HTML +.\" +\fBNON-AUTOTOOLS-BUILD\fP. +.\" +You should consult this file as well as the +.\" HTML +.\" +\fBREADME\fP +.\" +file if you are building in a non-Unix-like environment. +. +. +.SH "PCRE2 BUILD-TIME OPTIONS" +.rs +.sp +The rest of this document describes the optional features of PCRE2 that can be +selected when the library is compiled. It assumes use of the \fBconfigure\fP +script, where the optional features are selected or deselected by providing +options to \fBconfigure\fP before running the \fBmake\fP command. However, the +same options can be selected in both Unix-like and non-Unix-like environments +if you are using \fBCMake\fP instead of \fBconfigure\fP to build PCRE2. +.P +If you are not using Autotools or \fBCMake\fP, option selection can be done by +editing the \fBconfig.h\fP file, or by passing parameter settings to the +compiler, as described in +.\" HTML +.\" +\fBNON-AUTOTOOLS-BUILD\fP. +.\" +.P +The complete list of options for \fBconfigure\fP (which includes the standard +ones such as the selection of the installation directory) can be obtained by +running +.sp + ./configure --help +.sp +The following sections include descriptions of options whose names begin with +--enable or --disable. These settings specify changes to the defaults for the +\fBconfigure\fP command. Because of the way that \fBconfigure\fP works, +--enable and --disable always come in pairs, so the complementary option always +exists as well, but as it specifies the default, it is not described. +. +. +.SH "BUILDING 8-BIT, 16-BIT AND 32-BIT LIBRARIES" +.rs +.sp +By default, a library called \fBlibpcre2-8\fP is built, containing functions +that take string arguments contained in vectors of bytes, interpreted either as +single-byte characters, or UTF-8 strings. You can also build two other +libraries, called \fBlibpcre2-16\fP and \fBlibpcre2-32\fP, which process +strings that are contained in vectors of 16-bit and 32-bit code units, +respectively. These can be interpreted either as single-unit characters or +UTF-16/UTF-32 strings. To build these additional libraries, add one or both of +the following to the \fBconfigure\fP command: +.sp + --enable-pcre16 + --enable-pcre32 +.sp +If you do not want the 8-bit library, add +.sp + --disable-pcre8 +.sp +as well. At least one of the three libraries must be built. Note that the POSIX +wrapper is for the 8-bit library only, and that \fBpcre2grep\fP is an 8-bit +program. Neither of these are built if you select only the 16-bit or 32-bit +libraries. +. +. +.SH "BUILDING SHARED AND STATIC LIBRARIES" +.rs +.sp +The Autotools PCRE2 building process uses \fBlibtool\fP to build both shared +and static libraries by default. You can suppress one of these by adding one of +.sp + --disable-shared + --disable-static +.sp +to the \fBconfigure\fP command, as required. +. +. +.SH "Unicode and UTF SUPPORT" +.rs +.sp +To build PCRE2 with support for Unicode and UTF character strings, add +.sp + --enable-unicode +.sp +to the \fBconfigure\fP command. This setting applies to all three libraries, +adding support for UTF-8 to the 8-bit library, support for UTF-16 to the 16-bit +library, and support for UTF-32 to the to the 32-bit library. +It is not possible to build one library with +UTF support and another without in the same configuration. +.P +Of itself, this setting does not make PCRE2 treat strings as UTF-8, UTF-16 or +UTF-32. As well as compiling PCRE2 with this option, you also have have to set +the PCRE2_UTF option when you call \fBpcre2_compile()\fP to compile a pattern. +.P +If you set --enable-unicode when compiling in an EBCDIC environment, PCRE2 +expects its input to be either ASCII or UTF-8 (depending on the run-time +option). It is not possible to support both EBCDIC and UTF-8 codes in the same +version of the library. Consequently, --enable-unicode and --enable-ebcdic are +mutually exclusive. +.P +UTF support allows the libraries to process character codepoints up to 0x10ffff +in the strings that they handle. It also provides support for accessing the +properties of such characters, using pattern escapes such as \eP, \ep, and \eX. +Only the general category properties such as \fILu\fP and \fINd\fP are +supported. Details are given in the +.\" HREF +\fBpcre2pattern\fP +.\" +documentation. +. +. +.SH "JUST-IN-TIME COMPILER SUPPORT" +.rs +.sp +Just-in-time compiler support is included in the build by specifying +.sp + --enable-jit +.sp +This support is available only for certain hardware architectures. If this +option is set for an unsupported architecture, a compile time error occurs. +See the +.\" HREF +\fBpcre2jit\fP +.\" +documentation for a discussion of JIT usage. When JIT support is enabled, +pcre2grep automatically makes use of it, unless you add +.sp + --disable-pcre2grep-jit +.sp +to the "configure" command. +. +. +.SH "CODE VALUE OF NEWLINE" +.rs +.sp +By default, PCRE2 interprets the linefeed (LF) character as indicating the end +of a line. This is the normal newline character on Unix-like systems. You can +compile PCRE2 to use carriage return (CR) instead, by adding +.sp + --enable-newline-is-cr +.sp +to the \fBconfigure\fP command. There is also a --enable-newline-is-lf option, +which explicitly specifies linefeed as the newline character. +.sp +Alternatively, you can specify that line endings are to be indicated by the two +character sequence CRLF. If you want this, add +.sp + --enable-newline-is-crlf +.sp +to the \fBconfigure\fP command. There is a fourth option, specified by +.sp + --enable-newline-is-anycrlf +.sp +which causes PCRE2 to recognize any of the three sequences CR, LF, or CRLF as +indicating a line ending. Finally, a fifth option, specified by +.sp + --enable-newline-is-any +.sp +causes PCRE2 to recognize any Unicode newline sequence. +.P +Whatever line ending convention is selected when PCRE2 is built can be +overridden when the library functions are called. At build time it is +conventional to use the standard for your operating system. +. +. +.SH "WHAT \eR MATCHES" +.rs +.sp +By default, the sequence \eR in a pattern matches any Unicode newline sequence, +whatever has been selected as the line ending sequence. If you specify +.sp + --enable-bsr-anycrlf +.sp +the default is changed so that \eR matches only CR, LF, or CRLF. Whatever is +selected when PCRE2 is built can be overridden when the library functions are +called. +. +. +.SH "HANDLING VERY LARGE PATTERNS" +.rs +.sp +Within a compiled pattern, offset values are used to point from one part to +another (for example, from an opening parenthesis to an alternation +metacharacter). By default, in the 8-bit and 16-bit libraries, two-byte values +are used for these offsets, leading to a maximum size for a compiled pattern of +around 64K. This is sufficient to handle all but the most gigantic patterns. +Nevertheless, some people do want to process truly enormous patterns, so it is +possible to compile PCRE2 to use three-byte or four-byte offsets by adding a +setting such as +.sp + --with-link-size=3 +.sp +to the \fBconfigure\fP command. The value given must be 2, 3, or 4. For the +16-bit library, a value of 3 is rounded up to 4. In these libraries, using +longer offsets slows down the operation of PCRE2 because it has to load +additional data when handling them. For the 32-bit library the value is always +4 and cannot be overridden; the value of --with-link-size is ignored. +. +. +.SH "AVOIDING EXCESSIVE STACK USAGE" +.rs +.sp +When matching with the \fBpcre2_match()\fP function, PCRE2 implements +backtracking by making recursive calls to an internal function called +\fBmatch()\fP. In environments where the size of the stack is limited, this can +severely limit PCRE2's operation. (The Unix environment does not usually suffer +from this problem, but it may sometimes be necessary to increase the maximum +stack size. There is a discussion in the +.\" HREF +\fBpcre2stack\fP +.\" +documentation.) An alternative approach to recursion that uses memory from the +heap to remember data, instead of using recursive function calls, has been +implemented to work round the problem of limited stack size. If you want to +build a version of PCRE2 that works this way, add +.sp + --disable-stack-for-recursion +.sp +to the \fBconfigure\fP command. By default, the system functions \fBmalloc()\fP +and \fBfree()\fP are called to manage the heap memory that is required, but +custom memory management functions can be called instead. PCRE2 runs noticeably +more slowly when built in this way. This option affects only the +\fBpcre2_match()\fP function; it is not relevant for \fBpcre2_dfa_match()\fP. +. +. +.SH "LIMITING PCRE2 RESOURCE USAGE" +.rs +.sp +Internally, PCRE2 has a function called \fBmatch()\fP, which it calls +repeatedly (sometimes recursively) when matching a pattern with the +\fBpcre2_match()\fP function. By controlling the maximum number of times this +function may be called during a single matching operation, a limit can be +placed on the resources used by a single call to \fBpcre2_match()\fP. The limit +can be changed at run time, as described in the +.\" HREF +\fBpcre2api\fP +.\" +documentation. The default is 10 million, but this can be changed by adding a +setting such as +.sp + --with-match-limit=500000 +.sp +to the \fBconfigure\fP command. This setting has no effect on the +\fBpcre2_dfa_match()\fP matching function. +.P +In some environments it is desirable to limit the depth of recursive calls of +\fBmatch()\fP more strictly than the total number of calls, in order to +restrict the maximum amount of stack (or heap, if --disable-stack-for-recursion +is specified) that is used. A second limit controls this; it defaults to the +value that is set for --with-match-limit, which imposes no additional +constraints. However, you can set a lower limit by adding, for example, +.sp + --with-match-limit-recursion=10000 +.sp +to the \fBconfigure\fP command. This value can also be overridden at run time. +. +. +.SH "CREATING CHARACTER TABLES AT BUILD TIME" +.rs +.sp +PCRE2 uses fixed tables for processing characters whose code points are less +than 256. By default, PCRE2 is built with a set of tables that are distributed +in the file \fIsrc/pcre2_chartables.c.dist\fP. These tables are for ASCII codes +only. If you add +.sp + --enable-rebuild-chartables +.sp +to the \fBconfigure\fP command, the distributed tables are no longer used. +Instead, a program called \fBdftables\fP is compiled and run. This outputs the +source for new set of tables, created in the default locale of your C run-time +system. (This method of replacing the tables does not work if you are cross +compiling, because \fBdftables\fP is run on the local host. If you need to +create alternative tables when cross compiling, you will have to do so "by +hand".) +. +. +.SH "USING EBCDIC CODE" +.rs +.sp +PCRE2 assumes by default that it will run in an environment where the character +code is ASCII (or Unicode, which is a superset of ASCII). This is the case for +most computer operating systems. PCRE2 can, however, be compiled to run in an +EBCDIC environment by adding +.sp + --enable-ebcdic +.sp +to the \fBconfigure\fP command. This setting implies +--enable-rebuild-chartables. You should only use it if you know that you are in +an EBCDIC environment (for example, an IBM mainframe operating system). The +--enable-ebcdic option is incompatible with --enable-unicode. +.P +The EBCDIC character that corresponds to an ASCII LF is assumed to have the +value 0x15 by default. However, in some EBCDIC environments, 0x25 is used. In +such an environment you should use +.sp + --enable-ebcdic-nl25 +.sp +as well as, or instead of, --enable-ebcdic. The EBCDIC character for CR has the +same value as in ASCII, namely, 0x0d. Whichever of 0x15 and 0x25 is \fInot\fP +chosen as LF is made to correspond to the Unicode NEL character (which, in +Unicode, is 0x85). +.P +The options that select newline behaviour, such as --enable-newline-is-cr, +and equivalent run-time options, refer to these character values in an EBCDIC +environment. +. +. +.SH "PCRE2GREP OPTIONS FOR COMPRESSED FILE SUPPORT" +.rs +.sp +By default, \fBpcre2grep\fP reads all files as plain text. You can build it so +that it recognizes files whose names end in \fB.gz\fP or \fB.bz2\fP, and reads +them with \fBlibz\fP or \fBlibbz2\fP, respectively, by adding one or both of +.sp + --enable-pcre2grep-libz + --enable-pcre2grep-libbz2 +.sp +to the \fBconfigure\fP command. These options naturally require that the +relevant libraries are installed on your system. Configuration will fail if +they are not. +. +. +.SH "PCRE2GREP BUFFER SIZE" +.rs +.sp +\fBpcre2grep\fP uses an internal buffer to hold a "window" on the file it is +scanning, in order to be able to output "before" and "after" lines when it +finds a match. The size of the buffer is controlled by a parameter whose +default value is 20K. The buffer itself is three times this size, but because +of the way it is used for holding "before" lines, the longest line that is +guaranteed to be processable is the parameter size. You can change the default +parameter value by adding, for example, +.sp + --with-pcre2grep-bufsize=50K +.sp +to the \fBconfigure\fP command. The caller of \fPpcre2grep\fP can, however, +override this value by specifying a run-time option. +. +. +.SH "PCRE2TEST OPTION FOR LIBREADLINE SUPPORT" +.rs +.sp +If you add one of +.sp + --enable-pcre2test-libreadline + --enable-pcre2test-libedit +.sp +to the \fBconfigure\fP command, \fBpcre2test\fP is linked with the +\fBlibreadline\fP or\fBlibedit\fP library, respectively, and when its input is +from a terminal, it reads it using the \fBreadline()\fP function. This provides +line-editing and history facilities. Note that \fBlibreadline\fP is +GPL-licensed, so if you distribute a binary of \fBpcre2test\fP linked in this +way, there may be licensing issues. These can be avoided by linking with +\fBlibedit\fP (which has a BSD licence) instead. +.P +Setting this option causes the \fB-lreadline\fP option to be added to the +\fBpcre2test\fP 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), some extra +configuration may be necessary. The INSTALL file for \fBlibreadline\fP says +this: +.sp + "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." +.sp +If your environment has not been set up so that an appropriate library is +automatically included, you may need to add something like +.sp + LIBS="-ncurses" +.sp +immediately before the \fBconfigure\fP command. +. +. +.SH "DEBUGGING WITH VALGRIND SUPPORT" +.rs +.sp +By adding the +.sp + --enable-valgrind +.sp +option to to the \fBconfigure\fP command, PCRE2 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 PCRE2 itself. +. +. +.SH "CODE COVERAGE REPORTING" +.rs +.sp +If your C compiler is gcc, you can build a version of PCRE2 that can generate a +code coverage report for its test suite. To enable this, you must install +\fBlcov\fP version 1.6 or above. Then specify +.sp + --enable-coverage +.sp +to the \fBconfigure\fP command and build PCRE2 in the usual way. +.P +Note that using \fBccache\fP (a caching C compiler) is incompatible with code +coverage reporting. If you have configured \fBccache\fP to run automatically +on your system, you must set the environment variable +.sp + CCACHE_DISABLE=1 +.sp +before running \fBmake\fP to build PCRE2, so that \fBccache\fP is not used. +.P +When --enable-coverage is used, the following addition targets are added to the +\fIMakefile\fP: +.sp + make coverage +.sp +This creates a fresh coverage report for the PCRE2 test suite. It is equivalent +to running "make coverage-reset", "make coverage-baseline", "make check", and +then "make coverage-report". +.sp + make coverage-reset +.sp +This zeroes the coverage counters, but does nothing else. +.sp + make coverage-baseline +.sp +This captures baseline coverage information. +.sp + make coverage-report +.sp +This creates the coverage report. +.sp + make coverage-clean-report +.sp +This removes the generated coverage report without cleaning the coverage data +itself. +.sp + make coverage-clean-data +.sp +This removes the captured coverage data without removing the coverage files +created at compile time (*.gcno). +.sp + make coverage-clean +.sp +This cleans all coverage data including the generated coverage report. For more +information about code coverage, see the \fBgcov\fP and \fBlcov\fP +documentation. +. +. +.SH "SEE ALSO" +.rs +.sp +\fBpcre2api\fP(3), \fBpcre2_config\fP(3). +. +. +.SH AUTHOR +.rs +.sp +.nf +Philip Hazel +University Computing Service +Cambridge CB2 3QH, England. +.fi +. +. +.SH REVISION +.rs +.sp +.nf +Last updated: 28 September 2014 +Copyright (c) 1997-2014 University of Cambridge. +.fi diff --git a/doc/pcre2compat.3 b/doc/pcre2compat.3 new file mode 100644 index 0000000..d40742d --- /dev/null +++ b/doc/pcre2compat.3 @@ -0,0 +1,190 @@ +.TH PCRE2COMPAT 3 "28 September 2014" "PCRE2 10.0" +.SH NAME +PCRE2 - Perl-compatible regular expressions (revised API) +.SH "DIFFERENCES BETWEEN PCRE2 AND PERL" +.rs +.sp +This document describes the differences in the ways that PCRE2 and Perl handle +regular expressions. The differences described here are with respect to Perl +versions 5.10 and above. +.P +1. PCRE2 has only a subset of Perl's Unicode support. Details of what it does +have are given in the +.\" HREF +\fBpcre2unicode\fP +.\" +page. +.P +2. PCRE2 allows repeat quantifiers only on parenthesized assertions, but they +do not mean what you might think. For example, (?!a){3} does not assert that +the next three characters are not "a". It just asserts that the next character +is not "a" three times (in principle: PCRE2 optimizes this to run the assertion +just once). Perl allows repeat quantifiers on other assertions such as \eb, but +these do not seem to have any use. +.P +3. Capturing subpatterns that occur inside negative lookahead assertions are +counted, but their entries in the offsets vector are never set. Perl sometimes +(but not always) sets its numerical variables from inside negative assertions. +.P +4. The following Perl escape sequences are not supported: \el, \eu, \eL, +\eU, and \eN when followed by a character name or Unicode value. (\eN on its +own, matching a non-newline character, is supported.) In fact these are +implemented by Perl's general string-handling and are not part of its pattern +matching engine. If any of these are encountered by PCRE2, an error is +generated by default. However, if the PCRE2_ALT_BSUX option is set, +\eU and \eu are interpreted as ECMAScript interprets them. +.P +5. The Perl escape sequences \ep, \eP, and \eX are supported only if PCRE2 is +built with Unicode support. The properties that can be tested with \ep and \eP +are limited to the general category properties such as Lu and Nd, script names +such as Greek or Han, and the derived properties Any and L&. PCRE2 does support +the Cs (surrogate) property, which Perl does not; the Perl documentation says +"Because Perl hides the need for the user to understand the internal +representation of Unicode characters, there is no need to implement the +somewhat messy concept of surrogates." +.P +6. PCRE2 does support the \eQ...\eE escape for quoting substrings. Characters +in between are treated as literals. This is slightly different from Perl in +that $ and @ are also handled as literals inside the quotes. In Perl, they +cause variable interpolation (but of course PCRE2 does not have variables). +Note the following examples: +.sp + Pattern PCRE2 matches Perl matches +.sp +.\" JOIN + \eQabc$xyz\eE abc$xyz abc followed by the + contents of $xyz + \eQabc\e$xyz\eE abc\e$xyz abc\e$xyz + \eQabc\eE\e$\eQxyz\eE abc$xyz abc$xyz +.sp +The \eQ...\eE sequence is recognized both inside and outside character classes. +.P +7. Fairly obviously, PCRE2 does not support the (?{code}) and (??{code}) +constructions. However, there is support for recursive patterns. This is not +available in Perl 5.8, but it is in Perl 5.10. Also, the PCRE2 "callout" +feature allows an external function to be called during pattern matching. See +the +.\" HREF +\fBpcre2callout\fP +.\" +documentation for details. +.P +8. Subpatterns that are called as subroutines (whether or not recursively) are +always treated as atomic groups in PCRE2. This is like Python, but unlike Perl. +Captured values that are set outside a subroutine call can be reference from +inside in PCRE2, but not in Perl. There is a discussion that explains these +differences in more detail in the +.\" HTML +.\" +section on recursion differences from Perl +.\" +in the +.\" HREF +\fBpcre2pattern\fP +.\" +page. +.P +9. If any of the backtracking control verbs are used in a subpattern that is +called as a subroutine (whether or not recursively), their effect is confined +to that subpattern; it does not extend to the surrounding pattern. This is not +always the case in Perl. In particular, if (*THEN) is present in a group that +is called as a subroutine, its action is limited to that group, even if the +group does not contain any | characters. Note that such subpatterns are +processed as anchored at the point where they are tested. +.P +10. If a pattern contains more than one backtracking control verb, the first +one that is backtracked onto acts. For example, in the pattern +A(*COMMIT)B(*PRUNE)C a failure in B triggers (*COMMIT), but a failure in C +triggers (*PRUNE). Perl's behaviour is more complex; in many cases it is the +same as PCRE2, but there are examples where it differs. +.P +11. Most backtracking verbs in assertions have their normal actions. They are +not confined to the assertion. +.P +12. There are some differences that are concerned with the settings of captured +strings when part of a pattern is repeated. For example, matching "aba" against +the pattern /^(a(b)?)+$/ in Perl leaves $2 unset, but in PCRE2 it is set to +"b". +.P +13. PCRE2's handling of duplicate subpattern numbers and duplicate subpattern +names is not as general as Perl's. This is a consequence of the fact the PCRE2 +works internally just with numbers, using an external table to translate +between numbers and names. In particular, a pattern such as (?|(?A)|(?\fP. When there is more than one pattern +(specified by the use of \fB-e\fP and/or \fB-f\fP), each pattern is applied to +each line in the order in which they are defined, except that all the \fB-e\fP +patterns are tried before the \fB-f\fP patterns. +.P +By default, as soon as one pattern matches a line, no further patterns are +considered. However, if \fB--colour\fP (or \fB--color\fP) is used to colour the +matching substrings, or if \fB--only-matching\fP, \fB--file-offsets\fP, or +\fB--line-offsets\fP is used to output only the part of the line that matched +(either shown literally, or as an offset), scanning resumes immediately +following the match, so that further matches on the same line can be found. If +there are multiple patterns, they are all tried on the remainder of the line, +but patterns that follow the one that matched are not tried on the earlier part +of the line. +.P +This behaviour means that the order in which multiple patterns are specified +can affect the output when one of the above options is used. This is no longer +the same behaviour as GNU grep, which now manages to display earlier matches +for later patterns (as long as there is no overlap). +.P +Patterns that can match an empty string are accepted, but empty string +matches are never recognized. An example is the pattern "(super)?(man)?", in +which all components are optional. This pattern finds all occurrences of both +"super" and "man"; the output differs from matching with "super|man" when only +the matching substrings are being shown. +.P +If the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variable is set, +\fBpcre2grep\fP uses the value to set a locale when calling the PCRE2 library. +The \fB--locale\fP option can be used to override this. +. +. +.SH "SUPPORT FOR COMPRESSED FILES" +.rs +.sp +It is possible to compile \fBpcre2grep\fP so that it uses \fBlibz\fP or +\fBlibbz2\fP to read files whose names end in \fB.gz\fP or \fB.bz2\fP, +respectively. You can find out whether your binary has support for one or both +of these file types by running it with the \fB--help\fP option. If the +appropriate support is not present, files are treated as plain text. The +standard input is always so treated. +. +. +.SH "BINARY FILES" +.rs +.sp +By default, a file that contains a binary zero byte within the first 1024 bytes +is identified as a binary file, and is processed specially. (GNU grep also +identifies binary files in this manner.) See the \fB--binary-files\fP option +for a means of changing the way binary files are handled. +. +. +.SH OPTIONS +.rs +.sp +The order in which some of the options appear can affect the output. For +example, both the \fB-h\fP and \fB-l\fP options affect the printing of file +names. Whichever comes later in the command line will be the one that takes +effect. Similarly, except where noted below, if an option is given twice, the +later setting is used. Numerical values for options may be followed by K or M, +to signify multiplication by 1024 or 1024*1024 respectively. +.TP 10 +\fB--\fP +This terminates the list of options. It is useful if the next item on the +command line starts with a hyphen but is not an option. This allows for the +processing of patterns and filenames that start with hyphens. +.TP +\fB-A\fP \fInumber\fP, \fB--after-context=\fP\fInumber\fP +Output \fInumber\fP lines of context after each matching line. If filenames +and/or line numbers are being output, a hyphen separator is used instead of a +colon for the context lines. A line containing "--" is output between each +group of lines, unless they are in fact contiguous in the input file. The value +of \fInumber\fP is expected to be relatively small. However, \fBpcre2grep\fP +guarantees to have up to 8K of following text available for context output. +.TP +\fB-a\fP, \fB--text\fP +Treat binary files as text. This is equivalent to +\fB--binary-files\fP=\fItext\fP. +.TP +\fB-B\fP \fInumber\fP, \fB--before-context=\fP\fInumber\fP +Output \fInumber\fP lines of context before each matching line. If filenames +and/or line numbers are being output, a hyphen separator is used instead of a +colon for the context lines. A line containing "--" is output between each +group of lines, unless they are in fact contiguous in the input file. The value +of \fInumber\fP is expected to be relatively small. However, \fBpcre2grep\fP +guarantees to have up to 8K of preceding text available for context output. +.TP +\fB--binary-files=\fP\fIword\fP +Specify how binary files are to be processed. If the word is "binary" (the +default), pattern matching is performed on binary files, but the only output is +"Binary file matches" when a match succeeds. If the word is "text", +which is equivalent to the \fB-a\fP or \fB--text\fP option, binary files are +processed in the same way as any other file. In this case, when a match +succeeds, the output may be binary garbage, which can have nasty effects if +sent to a terminal. If the word is "without-match", which is equivalent to the +\fB-I\fP option, binary files are not processed at all; they are assumed not to +be of interest. +.TP +\fB--buffer-size=\fP\fInumber\fP +Set the parameter that controls how much memory is used for buffering files +that are being scanned. +.TP +\fB-C\fP \fInumber\fP, \fB--context=\fP\fInumber\fP +Output \fInumber\fP lines of context both before and after each matching line. +This is equivalent to setting both \fB-A\fP and \fB-B\fP to the same value. +.TP +\fB-c\fP, \fB--count\fP +Do not output individual lines from the files that are being scanned; instead +output the number of lines that would otherwise have been shown. If no lines +are selected, the number zero is output. If several files are are being +scanned, a count is output for each of them. However, if the +\fB--files-with-matches\fP option is also used, only those files whose counts +are greater than zero are listed. When \fB-c\fP is used, the \fB-A\fP, +\fB-B\fP, and \fB-C\fP options are ignored. +.TP +\fB--colour\fP, \fB--color\fP +If this option is given without any data, it is equivalent to "--colour=auto". +If data is required, it must be given in the same shell item, separated by an +equals sign. +.TP +\fB--colour=\fP\fIvalue\fP, \fB--color=\fP\fIvalue\fP +This option specifies under what circumstances the parts of a line that matched +a pattern should be coloured in the output. By default, the output is not +coloured. The value (which is optional, see above) may be "never", "always", or +"auto". In the latter case, colouring happens only if the standard output is +connected to a terminal. More resources are used when colouring is enabled, +because \fBpcre2grep\fP has to search for all possible matches in a line, not +just one, in order to colour them all. +.sp +The colour that is used can be specified by setting the environment variable +PCRE2GREP_COLOUR or PCRE2GREP_COLOR. The value of this variable should be a +string of two numbers, separated by a semicolon. They are copied directly into +the control string for setting colour on a terminal, so it is your +responsibility to ensure that they make sense. If neither of the environment +variables is set, the default is "1;31", which gives red. +.TP +\fB-D\fP \fIaction\fP, \fB--devices=\fP\fIaction\fP +If an input path is not a regular file or a directory, "action" specifies how +it is to be processed. Valid values are "read" (the default) or "skip" +(silently skip the path). +.TP +\fB-d\fP \fIaction\fP, \fB--directories=\fP\fIaction\fP +If an input path is a directory, "action" specifies how it is to be processed. +Valid values are "read" (the default in non-Windows environments, for +compatibility with GNU grep), "recurse" (equivalent to the \fB-r\fP option), or +"skip" (silently skip the path, the default in Windows environments). In the +"read" case, directories are read as if they were ordinary files. In some +operating systems the effect of reading a directory like this is an immediate +end-of-file; in others it may provoke an error. +.TP +\fB-e\fP \fIpattern\fP, \fB--regex=\fP\fIpattern\fP, \fB--regexp=\fP\fIpattern\fP +Specify a pattern to be matched. This option can be used multiple times in +order to specify several patterns. It can also be used as a way of specifying a +single pattern that starts with a hyphen. When \fB-e\fP is used, no argument +pattern is taken from the command line; all arguments are treated as file +names. There is no limit to the number of patterns. They are applied to each +line in the order in which they are defined until one matches. +.sp +If \fB-f\fP is used with \fB-e\fP, the command line patterns are matched first, +followed by the patterns from the file(s), independent of the order in which +these options are specified. Note that multiple use of \fB-e\fP is not the same +as a single pattern with alternatives. For example, X|Y finds the first +character in a line that is X or Y, whereas if the two patterns are given +separately, with X first, \fBpcre2grep\fP finds X if it is present, even if it +follows Y in the line. It finds Y only if there is no X in the line. This +matters only if you are using \fB-o\fP or \fB--colo(u)r\fP to show the part(s) +of the line that matched. +.TP +\fB--exclude\fP=\fIpattern\fP +Files (but not directories) whose names match the pattern are skipped without +being processed. This applies to all files, whether listed on the command line, +obtained from \fB--file-list\fP, or by scanning a directory. The pattern is a +PCRE2 regular expression, and is matched against the final component of the file +name, not the entire path. The \fB-F\fP, \fB-w\fP, and \fB-x\fP options do not +apply to this pattern. The option may be given any number of times in order to +specify multiple patterns. If a file name matches both an \fB--include\fP +and an \fB--exclude\fP pattern, it is excluded. There is no short form for this +option. +.TP +\fB--exclude-from=\fP\fIfilename\fP +Treat each non-empty line of the file as the data for an \fB--exclude\fP +option. What constitutes a newline when reading the file is the operating +system's default. The \fB--newline\fP option has no effect on this option. This +option may be given more than once in order to specify a number of files to +read. +.TP +\fB--exclude-dir\fP=\fIpattern\fP +Directories whose names match the pattern are skipped without being processed, +whatever the setting of the \fB--recursive\fP option. This applies to all +directories, whether listed on the command line, obtained from +\fB--file-list\fP, or by scanning a parent directory. The pattern is a PCRE2 +regular expression, and is matched against the final component of the directory +name, not the entire path. The \fB-F\fP, \fB-w\fP, and \fB-x\fP options do not +apply to this pattern. The option may be given any number of times in order to +specify more than one pattern. If a directory matches both \fB--include-dir\fP +and \fB--exclude-dir\fP, it is excluded. There is no short form for this +option. +.TP +\fB-F\fP, \fB--fixed-strings\fP +Interpret each data-matching pattern as a list of fixed strings, separated by +newlines, instead of as a regular expression. What constitutes a newline for +this purpose is controlled by the \fB--newline\fP option. The \fB-w\fP (match +as a word) and \fB-x\fP (match whole line) options can be used with \fB-F\fP. +They apply to each of the fixed strings. A line is selected if any of the fixed +strings are found in it (subject to \fB-w\fP or \fB-x\fP, if present). This +option applies only to the patterns that are matched against the contents of +files; it does not apply to patterns specified by any of the \fB--include\fP or +\fB--exclude\fP options. +.TP +\fB-f\fP \fIfilename\fP, \fB--file=\fP\fIfilename\fP +Read patterns from the file, one per line, and match them against +each line of input. What constitutes a newline when reading the file is the +operating system's default. The \fB--newline\fP option has no effect on this +option. Trailing white space is removed from each line, and blank lines are +ignored. An empty file contains no patterns and therefore matches nothing. See +also the comments about multiple patterns versus a single pattern with +alternatives in the description of \fB-e\fP above. +.sp +If this option is given more than once, all the specified files are +read. A data line is output if any of the patterns match it. A filename can +be given as "-" to refer to the standard input. When \fB-f\fP is used, patterns +specified on the command line using \fB-e\fP may also be present; they are +tested before the file's patterns. However, no other pattern is taken from the +command line; all arguments are treated as the names of paths to be searched. +.TP +\fB--file-list\fP=\fIfilename\fP +Read a list of files and/or directories that are to be scanned from the given +file, one per line. Trailing white space is removed from each line, and blank +lines are ignored. These paths are processed before any that are listed on the +command line. The filename can be given as "-" to refer to the standard input. +If \fB--file\fP and \fB--file-list\fP are both specified as "-", patterns are +read first. This is useful only when the standard input is a terminal, from +which further lines (the list of files) can be read after an end-of-file +indication. If this option is given more than once, all the specified files are +read. +.TP +\fB--file-offsets\fP +Instead of showing lines or parts of lines that match, show each match as an +offset from the start of the file and a length, separated by a comma. In this +mode, no context is shown. That is, the \fB-A\fP, \fB-B\fP, and \fB-C\fP +options are ignored. If there is more than one match in a line, each of them is +shown separately. This option is mutually exclusive with \fB--line-offsets\fP +and \fB--only-matching\fP. +.TP +\fB-H\fP, \fB--with-filename\fP +Force the inclusion of the filename at the start of output lines when searching +a single file. By default, the filename is not shown in this case. For matching +lines, the filename is followed by a colon; for context lines, a hyphen +separator is used. If a line number is also being output, it follows the file +name. +.TP +\fB-h\fP, \fB--no-filename\fP +Suppress the output filenames when searching multiple files. By default, +filenames are shown when multiple files are searched. For matching lines, the +filename is followed by a colon; for context lines, a hyphen separator is used. +If a line number is also being output, it follows the file name. +.TP +\fB--help\fP +Output a help message, giving brief details of the command options and file +type support, and then exit. Anything else on the command line is +ignored. +.TP +\fB-I\fP +Treat binary files as never matching. This is equivalent to +\fB--binary-files\fP=\fIwithout-match\fP. +.TP +\fB-i\fP, \fB--ignore-case\fP +Ignore upper/lower case distinctions during comparisons. +.TP +\fB--include\fP=\fIpattern\fP +If any \fB--include\fP patterns are specified, the only files that are +processed are those that match one of the patterns (and do not match an +\fB--exclude\fP pattern). This option does not affect directories, but it +applies to all files, whether listed on the command line, obtained from +\fB--file-list\fP, or by scanning a directory. The pattern is a PCRE2 regular +expression, and is matched against the final component of the file name, not +the entire path. The \fB-F\fP, \fB-w\fP, and \fB-x\fP options do not apply to +this pattern. The option may be given any number of times. If a file name +matches both an \fB--include\fP and an \fB--exclude\fP pattern, it is excluded. +There is no short form for this option. +.TP +\fB--include-from=\fP\fIfilename\fP +Treat each non-empty line of the file as the data for an \fB--include\fP +option. What constitutes a newline for this purpose is the operating system's +default. The \fB--newline\fP option has no effect on this option. This option +may be given any number of times; all the files are read. +.TP +\fB--include-dir\fP=\fIpattern\fP +If any \fB--include-dir\fP patterns are specified, the only directories that +are processed are those that match one of the patterns (and do not match an +\fB--exclude-dir\fP pattern). This applies to all directories, whether listed +on the command line, obtained from \fB--file-list\fP, or by scanning a parent +directory. The pattern is a PCRE2 regular expression, and is matched against the +final component of the directory name, not the entire path. The \fB-F\fP, +\fB-w\fP, and \fB-x\fP options do not apply to this pattern. The option may be +given any number of times. If a directory matches both \fB--include-dir\fP and +\fB--exclude-dir\fP, it is excluded. There is no short form for this option. +.TP +\fB-L\fP, \fB--files-without-match\fP +Instead of outputting lines from the files, just output the names of the files +that do not contain any lines that would have been output. Each file name is +output once, on a separate line. +.TP +\fB-l\fP, \fB--files-with-matches\fP +Instead of outputting lines from the files, just output the names of the files +containing lines that would have been output. Each file name is output +once, on a separate line. Searching normally stops as soon as a matching line +is found in a file. However, if the \fB-c\fP (count) option is also used, +matching continues in order to obtain the correct count, and those files that +have at least one match are listed along with their counts. Using this option +with \fB-c\fP is a way of suppressing the listing of files with no matches. +.TP +\fB--label\fP=\fIname\fP +This option supplies a name to be used for the standard input when file names +are being output. If not supplied, "(standard input)" is used. There is no +short form for this option. +.TP +\fB--line-buffered\fP +When this option is given, input is read and processed line by line, and the +output is flushed after each write. By default, input is read in large chunks, +unless \fBpcre2grep\fP can determine that it is reading from a terminal (which +is currently possible only in Unix-like environments). Output to terminal is +normally automatically flushed by the operating system. This option can be +useful when the input or output is attached to a pipe and you do not want +\fBpcre2grep\fP to buffer up large amounts of data. However, its use will affect +performance, and the \fB-M\fP (multiline) option ceases to work. +.TP +\fB--line-offsets\fP +Instead of showing lines or parts of lines that match, show each match as a +line number, the offset from the start of the line, and a length. The line +number is terminated by a colon (as usual; see the \fB-n\fP option), and the +offset and length are separated by a comma. In this mode, no context is shown. +That is, the \fB-A\fP, \fB-B\fP, and \fB-C\fP options are ignored. If there is +more than one match in a line, each of them is shown separately. This option is +mutually exclusive with \fB--file-offsets\fP and \fB--only-matching\fP. +.TP +\fB--locale\fP=\fIlocale-name\fP +This option specifies a locale to be used for pattern matching. It overrides +the value in the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variables. If no +locale is specified, the PCRE2 library's default (usually the "C" locale) is +used. There is no short form for this option. +.TP +\fB--match-limit\fP=\fInumber\fP +Processing some regular expression patterns can require a very large amount of +memory, leading in some cases to a program crash if not enough is available. +Other patterns may take a very long time to search for all possible matching +strings. The \fBpcre2_exec()\fP function that is called by \fBpcre2grep\fP to do +the matching has two parameters that can limit the resources that it uses. +.sp +The \fB--match-limit\fP option provides a means of limiting resource usage +when processing patterns that are not going to match, but which have a very +large number of possibilities in their search trees. The classic example is a +pattern that uses nested unlimited repeats. Internally, PCRE2 uses a function +called \fBmatch()\fP which it calls repeatedly (sometimes recursively). The +limit set by \fB--match-limit\fP is imposed on the number of times this +function is called during a match, which has the effect of limiting the amount +of backtracking that can take place. +.sp +The \fB--recursion-limit\fP option is similar to \fB--match-limit\fP, but +instead of limiting the total number of times that \fBmatch()\fP is called, it +limits the depth of recursive calls, which in turn limits the amount of memory +that can be used. The recursion depth is a smaller number than the total number +of calls, because not all calls to \fBmatch()\fP are recursive. This limit is +of use only if it is set smaller than \fB--match-limit\fP. +.sp +There are no short forms for these options. The default settings are specified +when the PCRE2 library is compiled, with the default default being 10 million. +.TP +\fB-M\fP, \fB--multiline\fP +Allow patterns to match more than one line. When this option is given, patterns +may usefully contain literal newline characters and internal occurrences of ^ +and $ characters. The output for a successful match may consist of more than +one line, the last of which is the one in which the match ended. If the matched +string ends with a newline sequence the output ends at the end of that line. +.sp +When this option is set, the PCRE2 library is called in "multiline" mode. +There is a limit to the number of lines that can be matched, imposed by the way +that \fBpcre2grep\fP buffers the input file as it scans it. However, +\fBpcre2grep\fP ensures that at least 8K characters or the rest of the document +(whichever is the shorter) are available for forward matching, and similarly +the previous 8K characters (or all the previous characters, if fewer than 8K) +are guaranteed to be available for lookbehind assertions. This option does not +work when input is read line by line (see \fP--line-buffered\fP.) +.TP +\fB-N\fP \fInewline-type\fP, \fB--newline\fP=\fInewline-type\fP +The PCRE2 library supports five different conventions for indicating +the ends of lines. They are the single-character sequences CR (carriage return) +and LF (linefeed), the two-character sequence CRLF, an "anycrlf" convention, +which recognizes any of the preceding three types, and an "any" convention, in +which any Unicode line ending sequence is assumed to end a line. The Unicode +sequences are the three just mentioned, plus VT (vertical tab, U+000B), FF +(form feed, U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and +PS (paragraph separator, U+2029). +.sp +When the PCRE2 library is built, a default line-ending sequence is specified. +This is normally the standard sequence for the operating system. Unless +otherwise specified by this option, \fBpcre2grep\fP uses the library's default. +The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This +makes it possible to use \fBpcre2grep\fP to scan files that have come from other +environments without having to modify their line endings. If the data that is +being scanned does not agree with the convention set by this option, +\fBpcre2grep\fP may behave in strange ways. Note that this option does not +apply to files specified by the \fB-f\fP, \fB--exclude-from\fP, or +\fB--include-from\fP options, which are expected to use the operating system's +standard newline sequence. +.TP +\fB-n\fP, \fB--line-number\fP +Precede each output line by its line number in the file, followed by a colon +for matching lines or a hyphen for context lines. If the filename is also being +output, it precedes the line number. This option is forced if +\fB--line-offsets\fP is used. +.TP +\fB--no-jit\fP +If the PCRE2 library is built with support for just-in-time compiling (which +speeds up matching), \fBpcre2grep\fP automatically makes use of this, unless it +was explicitly disabled at build time. This option can be used to disable the +use of JIT at run time. It is provided for testing and working round problems. +It should never be needed in normal use. +.TP +\fB-o\fP, \fB--only-matching\fP +Show only the part of the line that matched a pattern instead of the whole +line. In this mode, no context is shown. That is, the \fB-A\fP, \fB-B\fP, and +\fB-C\fP options are ignored. If there is more than one match in a line, each +of them is shown separately. If \fB-o\fP is combined with \fB-v\fP (invert the +sense of the match to find non-matching lines), no output is generated, but the +return code is set appropriately. If the matched portion of the line is empty, +nothing is output unless the file name or line number are being printed, in +which case they are shown on an otherwise empty line. This option is mutually +exclusive with \fB--file-offsets\fP and \fB--line-offsets\fP. +.TP +\fB-o\fP\fInumber\fP, \fB--only-matching\fP=\fInumber\fP +Show only the part of the line that matched the capturing parentheses of the +given number. Up to 32 capturing parentheses are supported, and -o0 is +equivalent to \fB-o\fP without a number. Because these options can be given +without an argument (see above), if an argument is present, it must be given in +the same shell item, for example, -o3 or --only-matching=2. The comments given +for the non-argument case above also apply to this case. If the specified +capturing parentheses do not exist in the pattern, or were not set in the +match, nothing is output unless the file name or line number are being printed. +.sp +If this option is given multiple times, multiple substrings are output, in the +order the options are given. For example, -o3 -o1 -o3 causes the substrings +matched by capturing parentheses 3 and 1 and then 3 again to be output. By +default, there is no separator (but see the next option). +.TP +\fB--om-separator\fP=\fItext\fP +Specify a separating string for multiple occurrences of \fB-o\fP. The default +is an empty string. Separating strings are never coloured. +.TP +\fB-q\fP, \fB--quiet\fP +Work quietly, that is, display nothing except error messages. The exit +status indicates whether or not any matches were found. +.TP +\fB-r\fP, \fB--recursive\fP +If any given path is a directory, recursively scan the files it contains, +taking note of any \fB--include\fP and \fB--exclude\fP settings. By default, a +directory is read as a normal file; in some operating systems this gives an +immediate end-of-file. This option is a shorthand for setting the \fB-d\fP +option to "recurse". +.TP +\fB--recursion-limit\fP=\fInumber\fP +See \fB--match-limit\fP above. +.TP +\fB-s\fP, \fB--no-messages\fP +Suppress error messages about non-existent or unreadable files. Such files are +quietly skipped. However, the return code is still 2, even if matches were +found in other files. +.TP +\fB-u\fP, \fB--utf-8\fP +Operate in UTF-8 mode. This option is available only if PCRE2 has been compiled +with UTF-8 support. All patterns (including those for any \fB--exclude\fP and +\fB--include\fP options) and all subject lines that are scanned must be valid +strings of UTF-8 characters. +.TP +\fB-V\fP, \fB--version\fP +Write the version numbers of \fBpcre2grep\fP and the PCRE2 library to the +standard output and then exit. Anything else on the command line is +ignored. +.TP +\fB-v\fP, \fB--invert-match\fP +Invert the sense of the match, so that lines which do \fInot\fP match any of +the patterns are the ones that are found. +.TP +\fB-w\fP, \fB--word-regex\fP, \fB--word-regexp\fP +Force the patterns to match only whole words. This is equivalent to having \eb +at the start and end of the pattern. This option applies only to the patterns +that are matched against the contents of files; it does not apply to patterns +specified by any of the \fB--include\fP or \fB--exclude\fP options. +.TP +\fB-x\fP, \fB--line-regex\fP, \fB--line-regexp\fP +Force the patterns to be anchored (each must start matching at the beginning of +a line) and in addition, require them to match entire lines. This is equivalent +to having ^ and $ characters at the start and end of each alternative branch in +every pattern. This option applies only to the patterns that are matched +against the contents of files; it does not apply to patterns specified by any +of the \fB--include\fP or \fB--exclude\fP options. +. +. +.SH "ENVIRONMENT VARIABLES" +.rs +.sp +The environment variables \fBLC_ALL\fP and \fBLC_CTYPE\fP are examined, in that +order, for a locale. The first one that is set is used. This can be overridden +by the \fB--locale\fP option. If no locale is set, the PCRE2 library's default +(usually the "C" locale) is used. +. +. +.SH "NEWLINES" +.rs +.sp +The \fB-N\fP (\fB--newline\fP) option allows \fBpcre2grep\fP to scan files with +different newline conventions from the default. Any parts of the input files +that are written to the standard output are copied identically, with whatever +newline sequences they have in the input. However, the setting of this option +does not affect the interpretation of files specified by the \fB-f\fP, +\fB--exclude-from\fP, or \fB--include-from\fP options, which are assumed to use +the operating system's standard newline sequence, nor does it affect the way in +which \fBpcre2grep\fP writes informational messages to the standard error and +output streams. For these it uses the string "\en" to indicate newlines, +relying on the C I/O library to convert this to an appropriate sequence. +. +. +.SH "OPTIONS COMPATIBILITY" +.rs +.sp +Many of the short and long forms of \fBpcre2grep\fP's options are the same +as in the GNU \fBgrep\fP program. Any long option of the form +\fB--xxx-regexp\fP (GNU terminology) is also available as \fB--xxx-regex\fP +(PCRE2 terminology). However, the \fB--file-list\fP, \fB--file-offsets\fP, +\fB--include-dir\fP, \fB--line-offsets\fP, \fB--locale\fP, \fB--match-limit\fP, +\fB-M\fP, \fB--multiline\fP, \fB-N\fP, \fB--newline\fP, \fB--om-separator\fP, +\fB--recursion-limit\fP, \fB-u\fP, and \fB--utf-8\fP options are specific to +\fBpcre2grep\fP, as is the use of the \fB--only-matching\fP option with a +capturing parentheses number. +.P +Although most of the common options work the same way, a few are different in +\fBpcre2grep\fP. For example, the \fB--include\fP option's argument is a glob +for GNU \fBgrep\fP, but a regular expression for \fBpcre2grep\fP. If both the +\fB-c\fP and \fB-l\fP options are given, GNU grep lists only file names, +without counts, but \fBpcre2grep\fP gives the counts. +. +. +.SH "OPTIONS WITH DATA" +.rs +.sp +There are four different ways in which an option with data can be specified. +If a short form option is used, the data may follow immediately, or (with one +exception) in the next command line item. For example: +.sp + -f/some/file + -f /some/file +.sp +The exception is the \fB-o\fP option, which may appear with or without data. +Because of this, if data is present, it must follow immediately in the same +item, for example -o3. +.P +If a long form option is used, the data may appear in the same command line +item, separated by an equals character, or (with two exceptions) it may appear +in the next command line item. For example: +.sp + --file=/some/file + --file /some/file +.sp +Note, however, that if you want to supply a file name beginning with ~ as data +in a shell command, and have the shell expand ~ to a home directory, you must +separate the file name from the option, because the shell does not treat ~ +specially unless it is at the start of an item. +.P +The exceptions to the above are the \fB--colour\fP (or \fB--color\fP) and +\fB--only-matching\fP options, for which the data is optional. If one of these +options does have data, it must be given in the first form, using an equals +character. Otherwise \fBpcre2grep\fP will assume that it has no data. +. +. +.SH "MATCHING ERRORS" +.rs +.sp +It is possible to supply a regular expression that takes a very long time to +fail to match certain lines. Such patterns normally involve nested indefinite +repeats, for example: (a+)*\ed when matched against a line of a's with no final +digit. The PCRE2 matching function has a resource limit that causes it to abort +in these circumstances. If this happens, \fBpcre2grep\fP outputs an error +message and the line that caused the problem to the standard error stream. If +there are more than 20 such errors, \fBpcre2grep\fP gives up. +.P +The \fB--match-limit\fP option of \fBpcre2grep\fP can be used to set the overall +resource limit; there is a second option called \fB--recursion-limit\fP that +sets a limit on the amount of memory (usually stack) that is used (see the +discussion of these options above). +. +. +.SH DIAGNOSTICS +.rs +.sp +Exit status is 0 if any matches were found, 1 if no matches were found, and 2 +for syntax errors, overlong lines, non-existent or inaccessible files (even if +matches were found in other files) or too many matching errors. Using the +\fB-s\fP option to suppress error messages about inaccessible files does not +affect the return code. +. +. +.SH "SEE ALSO" +.rs +.sp +\fBpcre2pattern\fP(3), \fBpcre2syntax\fP(3), \fBpcre2test\fP(1). +. +. +.SH AUTHOR +.rs +.sp +.nf +Philip Hazel +University Computing Service +Cambridge CB2 3QH, England. +.fi +. +. +.SH REVISION +.rs +.sp +.nf +Last updated: 28 September 2014 +Copyright (c) 1997-2014 University of Cambridge. +.fi diff --git a/doc/pcre2grep.txt b/doc/pcre2grep.txt new file mode 100644 index 0000000..c4b177c --- /dev/null +++ b/doc/pcre2grep.txt @@ -0,0 +1,741 @@ +PCRE2GREP(1) General Commands Manual PCRE2GREP(1) + + + +NAME + pcre2grep - a grep with Perl-compatible regular expressions. + +SYNOPSIS + pcre2grep [options] [long options] [pattern] [path1 path2 ...] + + +DESCRIPTION + + pcre2grep searches files for character patterns, in the same way as + other grep commands do, but it uses the PCRE2 regular expression + library to support patterns that are compatible with the regular + expressions of Perl 5. See pcre2syntax(3) for a quick-reference summary + of pattern syntax, or pcre2pattern(3) for a full description of the + syntax and semantics of the regular expressions that PCRE2 supports. + + Patterns, whether supplied on the command line or in a separate file, + are given without delimiters. For example: + + pcre2grep Thursday /etc/motd + + If you attempt to use delimiters (for example, by surrounding a pattern + with slashes, as is common in Perl scripts), they are interpreted as + part of the pattern. Quotes can of course be used to delimit patterns + on the command line because they are interpreted by the shell, and + indeed quotes are required if a pattern contains white space or shell + metacharacters. + + The first argument that follows any option settings is treated as the + single pattern to be matched when neither -e nor -f is present. Con- + versely, when one or both of these options are used to specify pat- + terns, all arguments are treated as path names. At least one of -e, -f, + or an argument pattern must be provided. + + If no files are specified, pcre2grep reads the standard input. The + standard input can also be referenced by a name consisting of a single + hyphen. For example: + + pcre2grep some-pattern /file1 - /file3 + + By default, each line that matches a pattern is copied to the standard + output, and if there is more than one file, the file name is output at + the start of each line, followed by a colon. However, there are options + that can change how pcre2grep behaves. In particular, the -M option + makes it possible to search for patterns that span line boundaries. + What defines a line boundary is controlled by the -N (--newline) + option. + + The amount of memory used for buffering files that are being scanned is + controlled by a parameter that can be set by the --buffer-size option. + The default value for this parameter is specified when pcre2grep is + built, with the default default being 20K. A block of memory three + times this size is used (to allow for buffering "before" and "after" + lines). An error occurs if a line overflows the buffer. + + Patterns can be no longer than 8K or BUFSIZ bytes, whichever is the + greater. BUFSIZ is defined in . When there is more than one + pattern (specified by the use of -e and/or -f), each pattern is applied + to each line in the order in which they are defined, except that all + the -e patterns are tried before the -f patterns. + + By default, as soon as one pattern matches a line, no further patterns + are considered. However, if --colour (or --color) is used to colour the + matching substrings, or if --only-matching, --file-offsets, or --line- + offsets is used to output only the part of the line that matched + (either shown literally, or as an offset), scanning resumes immediately + following the match, so that further matches on the same line can be + found. If there are multiple patterns, they are all tried on the + remainder of the line, but patterns that follow the one that matched + are not tried on the earlier part of the line. + + This behaviour means that the order in which multiple patterns are + specified can affect the output when one of the above options is used. + This is no longer the same behaviour as GNU grep, which now manages to + display earlier matches for later patterns (as long as there is no + overlap). + + Patterns that can match an empty string are accepted, but empty string + matches are never recognized. An example is the pattern + "(super)?(man)?", in which all components are optional. This pattern + finds all occurrences of both "super" and "man"; the output differs + from matching with "super|man" when only the matching substrings are + being shown. + + If the LC_ALL or LC_CTYPE environment variable is set, pcre2grep uses + the value to set a locale when calling the PCRE2 library. The --locale + option can be used to override this. + + +SUPPORT FOR COMPRESSED FILES + + It is possible to compile pcre2grep so that it uses libz or libbz2 to + read files whose names end in .gz or .bz2, respectively. You can find + out whether your binary has support for one or both of these file types + by running it with the --help option. If the appropriate support is not + present, files are treated as plain text. The standard input is always + so treated. + + +BINARY FILES + + By default, a file that contains a binary zero byte within the first + 1024 bytes is identified as a binary file, and is processed specially. + (GNU grep also identifies binary files in this manner.) See the + --binary-files option for a means of changing the way binary files are + handled. + + +OPTIONS + + The order in which some of the options appear can affect the output. + For example, both the -h and -l options affect the printing of file + names. Whichever comes later in the command line will be the one that + takes effect. Similarly, except where noted below, if an option is + given twice, the later setting is used. Numerical values for options + may be followed by K or M, to signify multiplication by 1024 or + 1024*1024 respectively. + + -- This terminates the list of options. It is useful if the next + item on the command line starts with a hyphen but is not an + option. This allows for the processing of patterns and file- + names that start with hyphens. + + -A number, --after-context=number + Output number lines of context after each matching line. If + filenames and/or line numbers are being output, a hyphen sep- + arator is used instead of a colon for the context lines. A + line containing "--" is output between each group of lines, + unless they are in fact contiguous in the input file. The + value of number is expected to be relatively small. However, + pcre2grep guarantees to have up to 8K of following text + available for context output. + + -a, --text + Treat binary files as text. This is equivalent to --binary- + files=text. + + -B number, --before-context=number + Output number lines of context before each matching line. If + filenames and/or line numbers are being output, a hyphen sep- + arator is used instead of a colon for the context lines. A + line containing "--" is output between each group of lines, + unless they are in fact contiguous in the input file. The + value of number is expected to be relatively small. However, + pcre2grep guarantees to have up to 8K of preceding text + available for context output. + + --binary-files=word + Specify how binary files are to be processed. If the word is + "binary" (the default), pattern matching is performed on + binary files, but the only output is "Binary file + matches" when a match succeeds. If the word is "text", which + is equivalent to the -a or --text option, binary files are + processed in the same way as any other file. In this case, + when a match succeeds, the output may be binary garbage, + which can have nasty effects if sent to a terminal. If the + word is "without-match", which is equivalent to the -I + option, binary files are not processed at all; they are + assumed not to be of interest. + + --buffer-size=number + Set the parameter that controls how much memory is used for + buffering files that are being scanned. + + -C number, --context=number + Output number lines of context both before and after each + matching line. This is equivalent to setting both -A and -B + to the same value. + + -c, --count + Do not output individual lines from the files that are being + scanned; instead output the number of lines that would other- + wise have been shown. If no lines are selected, the number + zero is output. If several files are are being scanned, a + count is output for each of them. However, if the --files- + with-matches option is also used, only those files whose + counts are greater than zero are listed. When -c is used, the + -A, -B, and -C options are ignored. + + --colour, --color + If this option is given without any data, it is equivalent to + "--colour=auto". If data is required, it must be given in + the same shell item, separated by an equals sign. + + --colour=value, --color=value + This option specifies under what circumstances the parts of a + line that matched a pattern should be coloured in the output. + By default, the output is not coloured. The value (which is + optional, see above) may be "never", "always", or "auto". In + the latter case, colouring happens only if the standard out- + put is connected to a terminal. More resources are used when + colouring is enabled, because pcre2grep has to search for all + possible matches in a line, not just one, in order to colour + them all. + + The colour that is used can be specified by setting the envi- + ronment variable PCRE2GREP_COLOUR or PCRE2GREP_COLOR. The + value of this variable should be a string of two numbers, + separated by a semicolon. They are copied directly into the + control string for setting colour on a terminal, so it is + your responsibility to ensure that they make sense. If nei- + ther of the environment variables is set, the default is + "1;31", which gives red. + + -D action, --devices=action + If an input path is not a regular file or a directory, + "action" specifies how it is to be processed. Valid values + are "read" (the default) or "skip" (silently skip the path). + + -d action, --directories=action + If an input path is a directory, "action" specifies how it is + to be processed. Valid values are "read" (the default in + non-Windows environments, for compatibility with GNU grep), + "recurse" (equivalent to the -r option), or "skip" (silently + skip the path, the default in Windows environments). In the + "read" case, directories are read as if they were ordinary + files. In some operating systems the effect of reading a + directory like this is an immediate end-of-file; in others it + may provoke an error. + + -e pattern, --regex=pattern, --regexp=pattern + Specify a pattern to be matched. This option can be used mul- + tiple times in order to specify several patterns. It can also + be used as a way of specifying a single pattern that starts + with a hyphen. When -e is used, no argument pattern is taken + from the command line; all arguments are treated as file + names. There is no limit to the number of patterns. They are + applied to each line in the order in which they are defined + until one matches. + + If -f is used with -e, the command line patterns are matched + first, followed by the patterns from the file(s), independent + of the order in which these options are specified. Note that + multiple use of -e is not the same as a single pattern with + alternatives. For example, X|Y finds the first character in a + line that is X or Y, whereas if the two patterns are given + separately, with X first, pcre2grep finds X if it is present, + even if it follows Y in the line. It finds Y only if there is + no X in the line. This matters only if you are using -o or + --colo(u)r to show the part(s) of the line that matched. + + --exclude=pattern + Files (but not directories) whose names match the pattern are + skipped without being processed. This applies to all files, + whether listed on the command line, obtained from --file- + list, or by scanning a directory. The pattern is a PCRE2 reg- + ular expression, and is matched against the final component + of the file name, not the entire path. The -F, -w, and -x + options do not apply to this pattern. The option may be given + any number of times in order to specify multiple patterns. If + a file name matches both an --include and an --exclude pat- + tern, it is excluded. There is no short form for this option. + + --exclude-from=filename + Treat each non-empty line of the file as the data for an + --exclude option. What constitutes a newline when reading the + file is the operating system's default. The --newline option + has no effect on this option. This option may be given more + than once in order to specify a number of files to read. + + --exclude-dir=pattern + Directories whose names match the pattern are skipped without + being processed, whatever the setting of the --recursive + option. This applies to all directories, whether listed on + the command line, obtained from --file-list, or by scanning a + parent directory. The pattern is a PCRE2 regular expression, + and is matched against the final component of the directory + name, not the entire path. The -F, -w, and -x options do not + apply to this pattern. The option may be given any number of + times in order to specify more than one pattern. If a direc- + tory matches both --include-dir and --exclude-dir, it is + excluded. There is no short form for this option. + + -F, --fixed-strings + Interpret each data-matching pattern as a list of fixed + strings, separated by newlines, instead of as a regular + expression. What constitutes a newline for this purpose is + controlled by the --newline option. The -w (match as a word) + and -x (match whole line) options can be used with -F. They + apply to each of the fixed strings. A line is selected if any + of the fixed strings are found in it (subject to -w or -x, if + present). This option applies only to the patterns that are + matched against the contents of files; it does not apply to + patterns specified by any of the --include or --exclude + options. + + -f filename, --file=filename + Read patterns from the file, one per line, and match them + against each line of input. What constitutes a newline when + reading the file is the operating system's default. The + --newline option has no effect on this option. Trailing white + space is removed from each line, and blank lines are ignored. + An empty file contains no patterns and therefore matches + nothing. See also the comments about multiple patterns versus + a single pattern with alternatives in the description of -e + above. + + If this option is given more than once, all the specified + files are read. A data line is output if any of the patterns + match it. A filename can be given as "-" to refer to the + standard input. When -f is used, patterns specified on the + command line using -e may also be present; they are tested + before the file's patterns. However, no other pattern is + taken from the command line; all arguments are treated as the + names of paths to be searched. + + --file-list=filename + Read a list of files and/or directories that are to be + scanned from the given file, one per line. Trailing white + space is removed from each line, and blank lines are ignored. + These paths are processed before any that are listed on the + command line. The filename can be given as "-" to refer to + the standard input. If --file and --file-list are both spec- + ified as "-", patterns are read first. This is useful only + when the standard input is a terminal, from which further + lines (the list of files) can be read after an end-of-file + indication. If this option is given more than once, all the + specified files are read. + + --file-offsets + Instead of showing lines or parts of lines that match, show + each match as an offset from the start of the file and a + length, separated by a comma. In this mode, no context is + shown. That is, the -A, -B, and -C options are ignored. If + there is more than one match in a line, each of them is shown + separately. This option is mutually exclusive with --line- + offsets and --only-matching. + + -H, --with-filename + Force the inclusion of the filename at the start of output + lines when searching a single file. By default, the filename + is not shown in this case. For matching lines, the filename + is followed by a colon; for context lines, a hyphen separator + is used. If a line number is also being output, it follows + the file name. + + -h, --no-filename + Suppress the output filenames when searching multiple files. + By default, filenames are shown when multiple files are + searched. For matching lines, the filename is followed by a + colon; for context lines, a hyphen separator is used. If a + line number is also being output, it follows the file name. + + --help Output a help message, giving brief details of the command + options and file type support, and then exit. Anything else + on the command line is ignored. + + -I Treat binary files as never matching. This is equivalent to + --binary-files=without-match. + + -i, --ignore-case + Ignore upper/lower case distinctions during comparisons. + + --include=pattern + If any --include patterns are specified, the only files that + are processed are those that match one of the patterns (and + do not match an --exclude pattern). This option does not + affect directories, but it applies to all files, whether + listed on the command line, obtained from --file-list, or by + scanning a directory. The pattern is a PCRE2 regular expres- + sion, and is matched against the final component of the file + name, not the entire path. The -F, -w, and -x options do not + apply to this pattern. The option may be given any number of + times. If a file name matches both an --include and an + --exclude pattern, it is excluded. There is no short form + for this option. + + --include-from=filename + Treat each non-empty line of the file as the data for an + --include option. What constitutes a newline for this purpose + is the operating system's default. The --newline option has + no effect on this option. This option may be given any number + of times; all the files are read. + + --include-dir=pattern + If any --include-dir patterns are specified, the only direc- + tories that are processed are those that match one of the + patterns (and do not match an --exclude-dir pattern). This + applies to all directories, whether listed on the command + line, obtained from --file-list, or by scanning a parent + directory. The pattern is a PCRE2 regular expression, and is + matched against the final component of the directory name, + not the entire path. The -F, -w, and -x options do not apply + to this pattern. The option may be given any number of times. + If a directory matches both --include-dir and --exclude-dir, + it is excluded. There is no short form for this option. + + -L, --files-without-match + Instead of outputting lines from the files, just output the + names of the files that do not contain any lines that would + have been output. Each file name is output once, on a sepa- + rate line. + + -l, --files-with-matches + Instead of outputting lines from the files, just output the + names of the files containing lines that would have been out- + put. Each file name is output once, on a separate line. + Searching normally stops as soon as a matching line is found + in a file. However, if the -c (count) option is also used, + matching continues in order to obtain the correct count, and + those files that have at least one match are listed along + with their counts. Using this option with -c is a way of sup- + pressing the listing of files with no matches. + + --label=name + This option supplies a name to be used for the standard input + when file names are being output. If not supplied, "(standard + input)" is used. There is no short form for this option. + + --line-buffered + When this option is given, input is read and processed line + by line, and the output is flushed after each write. By + default, input is read in large chunks, unless pcre2grep can + determine that it is reading from a terminal (which is cur- + rently possible only in Unix-like environments). Output to + terminal is normally automatically flushed by the operating + system. This option can be useful when the input or output is + attached to a pipe and you do not want pcre2grep to buffer up + large amounts of data. However, its use will affect perfor- + mance, and the -M (multiline) option ceases to work. + + --line-offsets + Instead of showing lines or parts of lines that match, show + each match as a line number, the offset from the start of the + line, and a length. The line number is terminated by a colon + (as usual; see the -n option), and the offset and length are + separated by a comma. In this mode, no context is shown. + That is, the -A, -B, and -C options are ignored. If there is + more than one match in a line, each of them is shown sepa- + rately. This option is mutually exclusive with --file-offsets + and --only-matching. + + --locale=locale-name + This option specifies a locale to be used for pattern match- + ing. It overrides the value in the LC_ALL or LC_CTYPE envi- + ronment variables. If no locale is specified, the PCRE2 + library's default (usually the "C" locale) is used. There is + no short form for this option. + + --match-limit=number + Processing some regular expression patterns can require a + very large amount of memory, leading in some cases to a pro- + gram crash if not enough is available. Other patterns may + take a very long time to search for all possible matching + strings. The pcre2_exec() function that is called by + pcre2grep to do the matching has two parameters that can + limit the resources that it uses. + + The --match-limit option provides a means of limiting + resource usage when processing patterns that are not going to + match, but which have a very large number of possibilities in + their search trees. The classic example is a pattern that + uses nested unlimited repeats. Internally, PCRE2 uses a func- + tion called match() which it calls repeatedly (sometimes + recursively). The limit set by --match-limit is imposed on + the number of times this function is called during a match, + which has the effect of limiting the amount of backtracking + that can take place. + + The --recursion-limit option is similar to --match-limit, but + instead of limiting the total number of times that match() is + called, it limits the depth of recursive calls, which in turn + limits the amount of memory that can be used. The recursion + depth is a smaller number than the total number of calls, + because not all calls to match() are recursive. This limit is + of use only if it is set smaller than --match-limit. + + There are no short forms for these options. The default set- + tings are specified when the PCRE2 library is compiled, with + the default default being 10 million. + + -M, --multiline + Allow patterns to match more than one line. When this option + is given, patterns may usefully contain literal newline char- + acters and internal occurrences of ^ and $ characters. The + output for a successful match may consist of more than one + line, the last of which is the one in which the match ended. + If the matched string ends with a newline sequence the output + ends at the end of that line. + + When this option is set, the PCRE2 library is called in "mul- + tiline" mode. There is a limit to the number of lines that + can be matched, imposed by the way that pcre2grep buffers the + input file as it scans it. However, pcre2grep ensures that at + least 8K characters or the rest of the document (whichever is + the shorter) are available for forward matching, and simi- + larly the previous 8K characters (or all the previous charac- + ters, if fewer than 8K) are guaranteed to be available for + lookbehind assertions. This option does not work when input + is read line by line (see --line-buffered.) + + -N newline-type, --newline=newline-type + The PCRE2 library supports five different conventions for + indicating the ends of lines. They are the single-character + sequences CR (carriage return) and LF (linefeed), the two- + character sequence CRLF, an "anycrlf" convention, which rec- + ognizes any of the preceding three types, and an "any" con- + vention, in which any Unicode line ending sequence is assumed + to end a line. The Unicode sequences are the three just men- + tioned, plus VT (vertical tab, U+000B), FF (form feed, + U+000C), NEL (next line, U+0085), LS (line separator, + U+2028), and PS (paragraph separator, U+2029). + + When the PCRE2 library is built, a default line-ending + sequence is specified. This is normally the standard + sequence for the operating system. Unless otherwise specified + by this option, pcre2grep uses the library's default. The + possible values for this option are CR, LF, CRLF, ANYCRLF, or + ANY. This makes it possible to use pcre2grep to scan files + that have come from other environments without having to mod- + ify their line endings. If the data that is being scanned + does not agree with the convention set by this option, + pcre2grep may behave in strange ways. Note that this option + does not apply to files specified by the -f, --exclude-from, + or --include-from options, which are expected to use the + operating system's standard newline sequence. + + -n, --line-number + Precede each output line by its line number in the file, fol- + lowed by a colon for matching lines or a hyphen for context + lines. If the filename is also being output, it precedes the + line number. This option is forced if --line-offsets is used. + + --no-jit If the PCRE2 library is built with support for just-in-time + compiling (which speeds up matching), pcre2grep automatically + makes use of this, unless it was explicitly disabled at build + time. This option can be used to disable the use of JIT at + run time. It is provided for testing and working round prob- + lems. It should never be needed in normal use. + + -o, --only-matching + Show only the part of the line that matched a pattern instead + of the whole line. In this mode, no context is shown. That + is, the -A, -B, and -C options are ignored. If there is more + than one match in a line, each of them is shown separately. + If -o is combined with -v (invert the sense of the match to + find non-matching lines), no output is generated, but the + return code is set appropriately. If the matched portion of + the line is empty, nothing is output unless the file name or + line number are being printed, in which case they are shown + on an otherwise empty line. This option is mutually exclusive + with --file-offsets and --line-offsets. + + -onumber, --only-matching=number + Show only the part of the line that matched the capturing + parentheses of the given number. Up to 32 capturing parenthe- + ses are supported, and -o0 is equivalent to -o without a num- + ber. Because these options can be given without an argument + (see above), if an argument is present, it must be given in + the same shell item, for example, -o3 or --only-matching=2. + The comments given for the non-argument case above also apply + to this case. If the specified capturing parentheses do not + exist in the pattern, or were not set in the match, nothing + is output unless the file name or line number are being + printed. + + If this option is given multiple times, multiple substrings + are output, in the order the options are given. For example, + -o3 -o1 -o3 causes the substrings matched by capturing paren- + theses 3 and 1 and then 3 again to be output. By default, + there is no separator (but see the next option). + + --om-separator=text + Specify a separating string for multiple occurrences of -o. + The default is an empty string. Separating strings are never + coloured. + + -q, --quiet + Work quietly, that is, display nothing except error messages. + The exit status indicates whether or not any matches were + found. + + -r, --recursive + If any given path is a directory, recursively scan the files + it contains, taking note of any --include and --exclude set- + tings. By default, a directory is read as a normal file; in + some operating systems this gives an immediate end-of-file. + This option is a shorthand for setting the -d option to + "recurse". + + --recursion-limit=number + See --match-limit above. + + -s, --no-messages + Suppress error messages about non-existent or unreadable + files. Such files are quietly skipped. However, the return + code is still 2, even if matches were found in other files. + + -u, --utf-8 + Operate in UTF-8 mode. This option is available only if PCRE2 + has been compiled with UTF-8 support. All patterns (including + those for any --exclude and --include options) and all sub- + ject lines that are scanned must be valid strings of UTF-8 + characters. + + -V, --version + Write the version numbers of pcre2grep and the PCRE2 library + to the standard output and then exit. Anything else on the + command line is ignored. + + -v, --invert-match + Invert the sense of the match, so that lines which do not + match any of the patterns are the ones that are found. + + -w, --word-regex, --word-regexp + Force the patterns to match only whole words. This is equiva- + lent to having \b at the start and end of the pattern. This + option applies only to the patterns that are matched against + the contents of files; it does not apply to patterns speci- + fied by any of the --include or --exclude options. + + -x, --line-regex, --line-regexp + Force the patterns to be anchored (each must start matching + at the beginning of a line) and in addition, require them to + match entire lines. This is equivalent to having ^ and $ + characters at the start and end of each alternative branch in + every pattern. This option applies only to the patterns that + are matched against the contents of files; it does not apply + to patterns specified by any of the --include or --exclude + options. + + +ENVIRONMENT VARIABLES + + The environment variables LC_ALL and LC_CTYPE are examined, in that + order, for a locale. The first one that is set is used. This can be + overridden by the --locale option. If no locale is set, the PCRE2 + library's default (usually the "C" locale) is used. + + +NEWLINES + + The -N (--newline) option allows pcre2grep to scan files with different + newline conventions from the default. Any parts of the input files that + are written to the standard output are copied identically, with what- + ever newline sequences they have in the input. However, the setting of + this option does not affect the interpretation of files specified by + the -f, --exclude-from, or --include-from options, which are assumed to + use the operating system's standard newline sequence, nor does it + affect the way in which pcre2grep writes informational messages to the + standard error and output streams. For these it uses the string "\n" to + indicate newlines, relying on the C I/O library to convert this to an + appropriate sequence. + + +OPTIONS COMPATIBILITY + + Many of the short and long forms of pcre2grep's options are the same as + in the GNU grep program. Any long option of the form --xxx-regexp (GNU + terminology) is also available as --xxx-regex (PCRE2 terminology). How- + ever, the --file-list, --file-offsets, --include-dir, --line-offsets, + --locale, --match-limit, -M, --multiline, -N, --newline, --om-separa- + tor, --recursion-limit, -u, and --utf-8 options are specific to + pcre2grep, as is the use of the --only-matching option with a capturing + parentheses number. + + Although most of the common options work the same way, a few are dif- + ferent in pcre2grep. For example, the --include option's argument is a + glob for GNU grep, but a regular expression for pcre2grep. If both the + -c and -l options are given, GNU grep lists only file names, without + counts, but pcre2grep gives the counts. + + +OPTIONS WITH DATA + + There are four different ways in which an option with data can be spec- + ified. If a short form option is used, the data may follow immedi- + ately, or (with one exception) in the next command line item. For exam- + ple: + + -f/some/file + -f /some/file + + The exception is the -o option, which may appear with or without data. + Because of this, if data is present, it must follow immediately in the + same item, for example -o3. + + If a long form option is used, the data may appear in the same command + line item, separated by an equals character, or (with two exceptions) + it may appear in the next command line item. For example: + + --file=/some/file + --file /some/file + + Note, however, that if you want to supply a file name beginning with ~ + as data in a shell command, and have the shell expand ~ to a home + directory, you must separate the file name from the option, because the + shell does not treat ~ specially unless it is at the start of an item. + + The exceptions to the above are the --colour (or --color) and --only- + matching options, for which the data is optional. If one of these + options does have data, it must be given in the first form, using an + equals character. Otherwise pcre2grep will assume that it has no data. + + +MATCHING ERRORS + + It is possible to supply a regular expression that takes a very long + time to fail to match certain lines. Such patterns normally involve + nested indefinite repeats, for example: (a+)*\d when matched against a + line of a's with no final digit. The PCRE2 matching function has a + resource limit that causes it to abort in these circumstances. If this + happens, pcre2grep outputs an error message and the line that caused + the problem to the standard error stream. If there are more than 20 + such errors, pcre2grep gives up. + + The --match-limit option of pcre2grep can be used to set the overall + resource limit; there is a second option called --recursion-limit that + sets a limit on the amount of memory (usually stack) that is used (see + the discussion of these options above). + + +DIAGNOSTICS + + Exit status is 0 if any matches were found, 1 if no matches were found, + and 2 for syntax errors, overlong lines, non-existent or inaccessible + files (even if matches were found in other files) or too many matching + errors. Using the -s option to suppress error messages about inaccessi- + ble files does not affect the return code. + + +SEE ALSO + + pcre2pattern(3), pcre2syntax(3), pcre2test(1). + + +AUTHOR + + Philip Hazel + University Computing Service + Cambridge CB2 3QH, England. + + +REVISION + + Last updated: 28 September 2014 + Copyright (c) 1997-2014 University of Cambridge. diff --git a/src/pcre2grep.c b/src/pcre2grep.c index f85f25e..71022ac 100644 --- a/src/pcre2grep.c +++ b/src/pcre2grep.c @@ -2997,7 +2997,7 @@ if (colour_option != NULL && strcmp(colour_option, "never") != 0) } if (do_colour) { - char *cs = getenv("pcre2grep_COLOUR"); + char *cs = getenv("PCRE2GREP_COLOUR"); if (cs == NULL) cs = getenv("PCRE2GREP_COLOR"); if (cs != NULL) colour_string = cs; } diff --git a/src/pcre2test.c b/src/pcre2test.c index 19fadd1..1aa40b4 100644 --- a/src/pcre2test.c +++ b/src/pcre2test.c @@ -5094,9 +5094,9 @@ printf(" 32-bit support\n"); (void)PCRE2_CONFIG(PCRE2_CONFIG_UNICODE, &rc, sizeof(rc)); if (rc != 0) - printf(" UTF support (Unicode version %s)\n", uversion); + printf(" UTF and UCP support (Unicode version %s)\n", uversion); else - printf(" No UTF support\n"); + printf(" No UTF or UCP support\n"); (void)PCRE2_CONFIG(PCRE2_CONFIG_JIT, &rc, sizeof(rc)); if (rc != 0) {