Perl version 5.10.0 documentation - perl NAME perl - Practical Extraction and Report Language SYNOPSIS perl [ -sTtuUWX ] [ -hv ] [ -V[:configvar] ] [ -cw ] [ -d[t][:debugger] ] [ -D[number/list] ] [ -pna ] [ -F pattern ] [ -l[octal] ] [ -0[octal/hexadecimal] ] [ -Idir ] [ -m[-]module ] [ -M[-]'module...' ] [ -f ] [ -C [ number/list] ] [ -P ] [ -S ] [ -x[dir] ] [ -i[extension] ] [ -e 'command' ] [ -- ] [ programfile ] [ argument ]... If you're new to Perl, you should start with perlintro, which is a general intro for beginners and provides some background to help younavigate the rest of Perl's extensive documentation. For ease of access, the Perl manual has been split up into several sections. Overview perlPerl overview (this section) perlintroPerl introduction for beginners perltocPerl documentation table of contents Tutorials perlreftutPerl references short introduction perldscPerl data structures intro perllolPerl data structures: arrays of arrays perlrequick Perl regular expressions quick start perlretutPerl regular expressions tutorial perlbootPerl OO tutorial for beginners perltootPerl OO tutorial, part 1 perltoocPerl OO tutorial, part 2 perlbotPerl OO tricks and examples perlstylePerl style guide perlcheatPerl cheat sheet perltrapPerl traps for the unwary perldebtutPerl debugging tutorial perlfaqPerl frequently asked questions perlfaq1General Questions About Perl perlfaq2Obtaining and Learning about Perl perlfaq3Programming Tools perlfaq4Data Manipulation perlfaq5Files and Formats perlfaq6Regexes perlfaq7Perl Language Issues perlfaq8System Interaction perlfaq9Networking Reference Manual perlsynPerl syntax perldataPerl data structures perlopPerl operators and precedence perlsubPerl subroutines http://perldoc.perl.org Page 1 Perl version 5.10.0 documentation - perl perlfuncPerl built-in functions perlopentutPerl open() tutorial perlpacktutPerl pack() and unpack() tutorial perlpodPerl plain old documentation perlpodspec Perl plain old documentation format specification perlrunPerl execution and options perldiagPerl diagnostic messages perllexwarn Perl warnings and their control perldebugPerl debugging perlvarPerl predefined variables perlrePerl regular expressions, the rest of the story perlrebackslashPerl regular expression backslash sequences perlrecharclassPerl regular expression character classes perlrerefPerl regular expressions quick reference perlrefPerl references, the rest of the story perlformPerl formats perlobjPerl objects perltiePerl objects hidden behind simple variables perldbmfilterPerl DBM filters perlipcPerl interprocess communication perlforkPerl fork() information perlnumberPerl number semantics perlthrtutPerl threads tutorial perlothrtutOld Perl threads tutorial perlportPerl portability guide perllocalePerl locale support perluniintroPerl Unicode introduction perlunicode Perl Unicode support perlunifaqPerl Unicode FAQ perlunitutPerl Unicode tutorial perlebcdicConsiderations for running Perl on EBCDIC platforms perlsecPerl security perlmodPerl modules: how they work perlmodlibPerl modules: how to write and use perlmodstylePerl modules: how to write modules with style perlmodinstallPerl modules: how to install from CPAN perlnewmodPerl modules: preparing a new module for distribution perlpragmaPerl modules: writing a user pragma perlutilutilities packaged with the Perl distribution perlcompile Perl compiler suite intro perlfilterPerl source filters perlglossaryPerl Glossary http://perldoc.perl.org Page 2 Perl version 5.10.0 documentation - perl Internals and C Language Interface perlembedPerl ways to embed perl in your C or C++ application perldebguts Perl debugging guts and tips perlxstutPerl XS tutorial perlxsPerl XS application programming interface perlclibInternal replacements for standard C library functions perlgutsPerl internal functions for those doing extensions perlcallPerl calling conventions from C perlreapiPerl regular expression plugin interface perlregutsPerl regular expression engine internals perlapiPerl API listing (autogenerated) perlinternPerl internal functions (autogenerated) perliolC API for Perl's implementation of IO in Layers perlapioPerl internal IO abstraction interface perlhackPerl hackers guide Miscellaneous perlbookPerl book information perlcommunityPerl community information perltodoPerl things to do perldocLook up Perl documentation in Pod format perlhistPerl history records perldeltaPerl changes since previous version perl595deltaPerl changes in version 5.9.5 perl594deltaPerl changes in version 5.9.4 perl593deltaPerl changes in version 5.9.3 perl592deltaPerl changes in version 5.9.2 perl591deltaPerl changes in version 5.9.1 perl590deltaPerl changes in version 5.9.0 perl588deltaPerl changes in version 5.8.8 perl587deltaPerl changes in version 5.8.7 perl586deltaPerl changes in version 5.8.6 perl585deltaPerl changes in version 5.8.5 perl584deltaPerl changes in version 5.8.4 perl583deltaPerl changes in version 5.8.3 perl582deltaPerl changes in version 5.8.2 perl581deltaPerl changes in version 5.8.1 perl58delta Perl changes in version 5.8.0 perl573deltaPerl changes in version 5.7.3 perl572deltaPerl changes in version 5.7.2 perl571deltaPerl changes in version 5.7.1 perl570deltaPerl changes in version 5.7.0 perl561deltaPerl changes in version 5.6.1 perl56delta Perl changes in version 5.6 perl5005deltaPerl changes in version 5.005 perl5004deltaPerl changes in version 5.004 perlartisticPerl Artistic License perlgplGNU General Public License http://perldoc.perl.org Page 3 Perl version 5.10.0 documentation - perl Language-Specific perlcnPerl for Simplified Chinese (in EUC-CN) perljpPerl for Japanese (in EUC-JP) perlkoPerl for Korean (in EUC-KR) perltwPerl for Traditional Chinese (in Big5) Platform-Specific perlaixPerl notes for AIX perlamigaPerl notes for AmigaOS perlapolloPerl notes for Apollo DomainOS perlbeosPerl notes for BeOS perlbs2000Perl notes for POSIX-BC BS2000 perlcePerl notes for WinCE perlcygwinPerl notes for Cygwin perldguxPerl notes for DG/UX perldosPerl notes for DOS perlepocPerl notes for EPOC perlfreebsd Perl notes for FreeBSD perlhpuxPerl notes for HP-UX perlhurdPerl notes for Hurd perlirixPerl notes for Irix perllinuxPerl notes for Linux perlmachten Perl notes for Power MachTen perlmacosPerl notes for Mac OS (Classic) perlmacosxPerl notes for Mac OS X perlmintPerl notes for MiNT perlmpeixPerl notes for MPE/iX perlnetware Perl notes for NetWare perlopenbsd Perl notes for OpenBSD perlos2Perl notes for OS/2 perlos390Perl notes for OS/390 perlos400Perl notes for OS/400 perlplan9Perl notes for Plan 9 perlqnxPerl notes for QNX perlriscosPerl notes for RISC OS perlsolaris Perl notes for Solaris perlsymbian Perl notes for Symbian perltru64Perl notes for Tru64 perlutsPerl notes for UTS perlvmesaPerl notes for VM/ESA perlvmsPerl notes for VMS perlvosPerl notes for Stratus VOS perlwin32Perl notes for Windows By default, the manpages listed above are installed in the /usr/local/man/ directory. Extensive additional documentation for Perl modules is available. Thedefault configuration for perl will place this additional documentationin the /usr/local/lib/perl5/man directory (or else in the man subdirectory of the Perl library directory). Some of this additionaldocumentation is distributed standard with Perl, but you'll also finddocumentation for third-party modules there. You should be able to view Perl's documentation with your man(1)program by including the proper directories in the appropriate start-upfiles, or in the MANPATH environment variable. To find out where theconfiguration has installed the manpages, type: perl -V:man.dir http://perldoc.perl.org Page 4 Perl version 5.10.0 documentation - perl If the directories have a common stem, such as /usr/local/man/man1and /usr/local/man/man3, you need only to add that stem(/usr/local/man) to your man(1) configuration files or your MANPATH environment variable. If they do not share a stem, you'll have to addboth stems. If that doesn't work for some reason, you can still use thesupplied perldoc script to view module information. You mightalso look into getting a replacement man program. If something strange has gone wrong with your program and you're notsure where you should look for help, try the -w switch first. Itwill often point out exactly where the trouble is. DESCRIPTION Perl is a language optimized for scanning arbitrarytext files, extracting information from those text files, and printingreports based on that information. It's also a good language for manysystem management tasks. The language is intended to be practical(easy to use, efficient, complete) rather than beautiful (tiny,elegant, minimal). Perl combines (in the author's opinion, anyway) some of the bestfeatures of C, sed, awk, and sh, so people familiar withthose languages should have little difficulty with it. (Languagehistorians will also note some vestiges of csh, Pascal, and evenBASIC-PLUS.) Expression syntax corresponds closely to Cexpression syntax. Unlike most Unix utilities, Perl does notarbitrarily limit the size of your data--if you've got the memory,Perl can slurp in your whole file as a single string. Recursion is ofunlimited depth. And the tables used by hashes (sometimes called"associative arrays") grow as necessary to prevent degradedperformance. Perl can use sophisticated pattern matching techniques toscan large amounts of data quickly. Although optimized forscanning text, Perl can also deal with binary data, and can make dbmfiles look like hashes. Setuid Perl scripts are safer than C programsthrough a dataflow tracing mechanism that