| =head1 NAME |
| |
| perl - The Perl 5 language interpreter |
| |
| =head1 SYNOPSIS |
| |
| B<perl> S<[ B<-sTtuUWX> ]> |
| S<[ B<-hv> ] [ B<-V>[:I<configvar>] ]> |
| S<[ B<-cw> ] [ B<-d>[B<t>][:I<debugger>] ] [ B<-D>[I<number/list>] ]> |
| S<[ B<-pna> ] [ B<-F>I<pattern> ] [ B<-l>[I<octal>] ] [ B<-0>[I<octal/hexadecimal>] ]> |
| S<[ B<-I>I<dir> ] [ B<-m>[B<->]I<module> ] [ B<-M>[B<->]I<'module...'> ] [ B<-f> ]> |
| S<[ B<-C [I<number/list>] >]> |
| S<[ B<-S> ]> |
| S<[ B<-x>[I<dir>] ]> |
| S<[ B<-i>[I<extension>] ]> |
| S<[ [B<-e>|B<-E>] I<'command'> ] [ B<--> ] [ I<programfile> ] [ I<argument> ]...> |
| |
| =head1 GETTING HELP |
| |
| The F<perldoc> program gives you access to all the documentation that comes |
| with Perl. You can get more documentation, tutorials and community support |
| online at L<http://www.perl.org/>. |
| |
| If you're new to Perl, you should start by running C<perldoc perlintro>, |
| which is a general intro for beginners and provides some background to help |
| you navigate the rest of Perl's extensive documentation. Run C<perldoc |
| perldoc> to learn more things you can do with F<perldoc>. |
| |
| For ease of access, the Perl manual has been split up into several sections. |
| |
| =begin buildtoc |
| |
| # This section is parsed by Porting/pod_lib.pl for use by pod/buildtoc etc |
| |
| flag =g perluniprops perlmodlib perlapi perlintern |
| flag =go perltoc |
| flag =ro perlcn perljp perlko perltw |
| flag = perlvms |
| |
| path perlfaq.* cpan/perlfaq/lib/ |
| path perlglossary cpan/perlfaq/lib/ |
| path perlxs(?:tut|typemap)? dist/ExtUtils-ParseXS/lib/ |
| path perldoc cpan/Pod-Perldoc/lib/ |
| |
| aux a2p c2ph h2ph h2xs perlbug pl2pm pod2html pod2man s2p splain xsubpp |
| |
| =end buildtoc |
| |
| =head2 Overview |
| |
| perl Perl overview (this section) |
| perlintro Perl introduction for beginners |
| perltoc Perl documentation table of contents |
| |
| =head2 Tutorials |
| |
| perlreftut Perl references short introduction |
| perldsc Perl data structures intro |
| perllol Perl data structures: arrays of arrays |
| |
| perlrequick Perl regular expressions quick start |
| perlretut Perl regular expressions tutorial |
| |
| perlootut Perl OO tutorial for beginners |
| |
| perlperf Perl Performance and Optimization Techniques |
| |
| perlstyle Perl style guide |
| |
| perlcheat Perl cheat sheet |
| perltrap Perl traps for the unwary |
| perldebtut Perl debugging tutorial |
| |
| perlfaq Perl frequently asked questions |
| perlfaq1 General Questions About Perl |
| perlfaq2 Obtaining and Learning about Perl |
| perlfaq3 Programming Tools |
| perlfaq4 Data Manipulation |
| perlfaq5 Files and Formats |
| perlfaq6 Regexes |
| perlfaq7 Perl Language Issues |
| perlfaq8 System Interaction |
| perlfaq9 Networking |
| |
| =head2 Reference Manual |
| |
| perlsyn Perl syntax |
| perldata Perl data structures |
| perlop Perl operators and precedence |
| perlsub Perl subroutines |
| perlfunc Perl built-in functions |
| perlopentut Perl open() tutorial |
| perlpacktut Perl pack() and unpack() tutorial |
| perlpod Perl plain old documentation |
| perlpodspec Perl plain old documentation format specification |
| perlpodstyle Perl POD style guide |
| perlrun Perl execution and options |
| perldiag Perl diagnostic messages |
| perllexwarn Perl warnings and their control |
| perldebug Perl debugging |
| perlvar Perl predefined variables |
| perlre Perl regular expressions, the rest of the story |
| perlrebackslash Perl regular expression backslash sequences |
| perlrecharclass Perl regular expression character classes |
| perlreref Perl regular expressions quick reference |
| perlref Perl references, the rest of the story |
| perlform Perl formats |
| perlobj Perl objects |
| perltie Perl objects hidden behind simple variables |
| perldbmfilter Perl DBM filters |
| |
| perlipc Perl interprocess communication |
| perlfork Perl fork() information |
| perlnumber Perl number semantics |
| |
| perlthrtut Perl threads tutorial |
| |
| perlport Perl portability guide |
| perllocale Perl locale support |
| perluniintro Perl Unicode introduction |
| perlunicode Perl Unicode support |
| perlunifaq Perl Unicode FAQ |
| perluniprops Index of Unicode Version 6.0.0 properties in Perl |
| perlunitut Perl Unicode tutorial |
| perlebcdic Considerations for running Perl on EBCDIC platforms |
| |
| perlsec Perl security |
| |
| perlmod Perl modules: how they work |
| perlmodlib Perl modules: how to write and use |
| perlmodstyle Perl modules: how to write modules with style |
| perlmodinstall Perl modules: how to install from CPAN |
| perlnewmod Perl modules: preparing a new module for distribution |
| perlpragma Perl modules: writing a user pragma |
| |
| perlutil utilities packaged with the Perl distribution |
| |
| perlfilter Perl source filters |
| |
| perldtrace Perl's support for DTrace |
| |
| perlglossary Perl Glossary |
| |
| =head2 Internals and C Language Interface |
| |
| perlembed Perl ways to embed perl in your C or C++ application |
| perldebguts Perl debugging guts and tips |
| perlxstut Perl XS tutorial |
| perlxs Perl XS application programming interface |
| perlxstypemap Perl XS C/Perl type conversion tools |
| perlclib Internal replacements for standard C library functions |
| perlguts Perl internal functions for those doing extensions |
| perlcall Perl calling conventions from C |
| perlmroapi Perl method resolution plugin interface |
| perlreapi Perl regular expression plugin interface |
| perlreguts Perl regular expression engine internals |
| |
| perlapi Perl API listing (autogenerated) |
| perlintern Perl internal functions (autogenerated) |
| perliol C API for Perl's implementation of IO in Layers |
| perlapio Perl internal IO abstraction interface |
| |
| perlhack Perl hackers guide |
| perlsource Guide to the Perl source tree |
| perlinterp Overview of the Perl interpreter source and how it works |
| perlhacktut Walk through the creation of a simple C code patch |
| perlhacktips Tips for Perl core C code hacking |
| perlpolicy Perl development policies |
| perlgit Using git with the Perl repository |
| |
| =head2 Miscellaneous |
| |
| perlbook Perl book information |
| perlcommunity Perl community information |
| |
| perldoc Look up Perl documentation in Pod format |
| |
| perlhist Perl history records |
| perldelta Perl changes since previous version |
| perl5161delta Perl changes in version 5.16.1 |
| perl5160delta Perl changes in version 5.16.0 |
| perl5160delta Perl changes in version 5.16.0 |
| perl5143delta Perl changes in version 5.14.3 |
| perl5142delta Perl changes in version 5.14.2 |
| perl5141delta Perl changes in version 5.14.1 |
| perl5140delta Perl changes in version 5.14.0 |
| perl5124delta Perl changes in version 5.12.4 |
| perl5123delta Perl changes in version 5.12.3 |
| perl5122delta Perl changes in version 5.12.2 |
| perl5121delta Perl changes in version 5.12.1 |
| perl5120delta Perl changes in version 5.12.0 |
| perl5101delta Perl changes in version 5.10.1 |
| perl5100delta Perl changes in version 5.10.0 |
| perl589delta Perl changes in version 5.8.9 |
| perl588delta Perl changes in version 5.8.8 |
| perl587delta Perl changes in version 5.8.7 |
| perl586delta Perl changes in version 5.8.6 |
| perl585delta Perl changes in version 5.8.5 |
| perl584delta Perl changes in version 5.8.4 |
| perl583delta Perl changes in version 5.8.3 |
| perl582delta Perl changes in version 5.8.2 |
| perl581delta Perl changes in version 5.8.1 |
| perl58delta Perl changes in version 5.8.0 |
| perl561delta Perl changes in version 5.6.1 |
| perl56delta Perl changes in version 5.6 |
| perl5005delta Perl changes in version 5.005 |
| perl5004delta Perl changes in version 5.004 |
| |
| perlexperiment A listing of experimental features in Perl |
| |
| perlartistic Perl Artistic License |
| perlgpl GNU General Public License |
| |
| =head2 Language-Specific |
| |
| =for buildtoc flag +r |
| |
| perlcn Perl for Simplified Chinese (in EUC-CN) |
| perljp Perl for Japanese (in EUC-JP) |
| perlko Perl for Korean (in EUC-KR) |
| perltw Perl for Traditional Chinese (in Big5) |
| |
| =head2 Platform-Specific |
| |
| perlaix Perl notes for AIX |
| perlamiga Perl notes for AmigaOS |
| perlbeos Perl notes for BeOS |
| perlbs2000 Perl notes for POSIX-BC BS2000 |
| perlce Perl notes for WinCE |
| perlcygwin Perl notes for Cygwin |
| perldgux Perl notes for DG/UX |
| perldos Perl notes for DOS |
| perlepoc Perl notes for EPOC |
| perlfreebsd Perl notes for FreeBSD |
| perlhaiku Perl notes for Haiku |
| perlhpux Perl notes for HP-UX |
| perlhurd Perl notes for Hurd |
| perlirix Perl notes for Irix |
| perllinux Perl notes for Linux |
| perlmacos Perl notes for Mac OS (Classic) |
| perlmacosx Perl notes for Mac OS X |
| perlmpeix Perl notes for MPE/iX |
| perlnetware Perl notes for NetWare |
| perlopenbsd Perl notes for OpenBSD |
| perlos2 Perl notes for OS/2 |
| perlos390 Perl notes for OS/390 |
| perlos400 Perl notes for OS/400 |
| perlplan9 Perl notes for Plan 9 |
| perlqnx Perl notes for QNX |
| perlriscos Perl notes for RISC OS |
| perlsolaris Perl notes for Solaris |
| perlsymbian Perl notes for Symbian |
| perltru64 Perl notes for Tru64 |
| perluts Perl notes for UTS |
| perlvmesa Perl notes for VM/ESA |
| perlvms Perl notes for VMS |
| perlvos Perl notes for Stratus VOS |
| perlwin32 Perl notes for Windows |
| |
| =for buildtoc flag -r |
| |
| =head2 Stubs for Deleted Documents |
| |
| perlboot |
| perlbot |
| perltodo |
| perltooc |
| perltoot |
| |
| =for buildtoc __END__ |
| |
| On a Unix-like system, these documentation files will usually also be |
| available as manpages for use with the F<man> program. |
| |
| In general, if something strange has gone wrong with your program and you're |
| not sure where you should look for help, try the B<-w> switch first. It will |
| often point out exactly where the trouble is. |
| |
| =head1 DESCRIPTION |
| |
| Perl officially stands for Practical Extraction and Report Language, |
| except when it doesn't. |
| |
| Perl was originally a language optimized for scanning arbitrary |
| text files, extracting information from those text files, and printing |
| reports based on that information. It quickly became a good language |
| for many system management tasks. Over the years, Perl has grown into |
| a general-purpose programming language. It's widely used for everything |
| from quick "one-liners" to full-scale application development. |
| |
| 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 best |
| features of C, B<sed>, B<awk>, and B<sh>, so people familiar with |
| those languages should have little difficulty with it. (Language |
| historians will also note some vestiges of B<csh>, Pascal, and even |
| BASIC-PLUS.) Expression syntax corresponds closely to C |
| expression syntax. Unlike most Unix utilities, Perl does not |
| arbitrarily 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 of |
| unlimited depth. And the tables used by hashes (sometimes called |
| "associative arrays") grow as necessary to prevent degraded |
| performance. Perl can use sophisticated pattern matching techniques to |
| scan large amounts of data quickly. Although optimized for |
| scanning text, Perl also has many excellent tools for slicing |
| and dicing binary data. |
| |
| But wait, there's more... |
| |
| Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete |
| rewrite that provides the following additional benefits: |
| |
| =over 4 |
| |
| =item * |
| |
| modularity and reusability using innumerable modules |
| |
| Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>. |
| |
| =item * |
| |
| embeddable and extensible |
| |
| Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlxstypemap>, |
| L<perlcall>, L<perlguts>, and L<xsubpp>. |
| |
| =item * |
| |
| roll-your-own magic variables (including multiple simultaneous DBM |
| implementations) |
| |
| Described in L<perltie> and L<AnyDBM_File>. |
| |
| =item * |
| |
| subroutines can now be overridden, autoloaded, and prototyped |
| |
| Described in L<perlsub>. |
| |
| =item * |
| |
| arbitrarily nested data structures and anonymous functions |
| |
| Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>. |
| |
| =item * |
| |
| object-oriented programming |
| |
| Described in L<perlobj> and L<perlootut>. |
| |
| =item * |
| |
| support for light-weight processes (threads) |
| |
| Described in L<perlthrtut> and L<threads>. |
| |
| =item * |
| |
| support for Unicode, internationalization, and localization |
| |
| Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>. |
| |
| =item * |
| |
| lexical scoping |
| |
| Described in L<perlsub>. |
| |
| =item * |
| |
| regular expression enhancements |
| |
| Described in L<perlre>, with additional examples in L<perlop>. |
| |
| =item * |
| |
| enhanced debugger and interactive Perl environment, |
| with integrated editor support |
| |
| Described in L<perldebtut>, L<perldebug> and L<perldebguts>. |
| |
| =item * |
| |
| POSIX 1003.1 compliant library |
| |
| Described in L<POSIX>. |
| |
| =back |
| |
| Okay, that's I<definitely> enough hype. |
| |
| =head1 AVAILABILITY |
| |
| Perl is available for most operating systems, including virtually |
| all Unix-like platforms. See L<perlport/"Supported Platforms"> |
| for a listing. |
| |
| =head1 ENVIRONMENT |
| |
| See L<perlrun>. |
| |
| =head1 AUTHOR |
| |
| Larry Wall <larry@wall.org>, with the help of oodles of other folks. |
| |
| If your Perl success stories and testimonials may be of help to others |
| who wish to advocate the use of Perl in their applications, |
| or if you wish to simply express your gratitude to Larry and the |
| Perl developers, please write to perl-thanks@perl.org . |
| |
| =head1 FILES |
| |
| "@INC" locations of perl libraries |
| |
| =head1 SEE ALSO |
| |
| http://www.perl.org/ the Perl homepage |
| http://www.perl.com/ Perl articles (O'Reilly) |
| http://www.cpan.org/ the Comprehensive Perl Archive |
| http://www.pm.org/ the Perl Mongers |
| |
| =head1 DIAGNOSTICS |
| |
| The C<use warnings> pragma (and the B<-w> switch) produces some |
| lovely diagnostics. |
| |
| See L<perldiag> for explanations of all Perl's diagnostics. The C<use |
| diagnostics> pragma automatically turns Perl's normally terse warnings |
| and errors into these longer forms. |
| |
| Compilation errors will tell you the line number of the error, with an |
| indication of the next token or token type that was to be examined. |
| (In a script passed to Perl via B<-e> switches, each |
| B<-e> is counted as one line.) |
| |
| Setuid scripts have additional constraints that can produce error |
| messages such as "Insecure dependency". See L<perlsec>. |
| |
| Did we mention that you should definitely consider using the B<-w> |
| switch? |
| |
| =head1 BUGS |
| |
| The B<-w> switch is not mandatory. |
| |
| Perl is at the mercy of your machine's definitions of various |
| operations such as type casting, atof(), and floating-point |
| output with sprintf(). |
| |
| If your stdio requires a seek or eof between reads and writes on a |
| particular stream, so does Perl. (This doesn't apply to sysread() |
| and syswrite().) |
| |
| While none of the built-in data types have any arbitrary size limits |
| (apart from memory size), there are still a few arbitrary limits: a |
| given variable name may not be longer than 251 characters. Line numbers |
| displayed by diagnostics are internally stored as short integers, |
| so they are limited to a maximum of 65535 (higher numbers usually being |
| affected by wraparound). |
| |
| You may mail your bug reports (be sure to include full configuration |
| information as output by the myconfig program in the perl source |
| tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded |
| in compiling perl, the L<perlbug> script in the F<utils/> subdirectory |
| can be used to help mail in a bug report. |
| |
| Perl actually stands for Pathologically Eclectic Rubbish Lister, but |
| don't tell anyone I said that. |
| |
| =head1 NOTES |
| |
| The Perl motto is "There's more than one way to do it." Divining |
| how many more is left as an exercise to the reader. |
| |
| The three principal virtues of a programmer are Laziness, |
| Impatience, and Hubris. See the Camel Book for why. |
| |
