perl - The Perl 5 language interpreter
perl[-sTtuUWX ][-hv ] [-V[:configvar] ][-cw ] [-d[t][:debugger] ] [-D[number/list] ][-pna ] [-Fpattern ] [-l[octal] ] [-0[octal/hexadecimal] ][-Idir ] [-m[-]module ] [-M[-]'module...' ] [-f ][-C [number/list]][-S ][-x[dir] ][-i[extension] ][ [-e|-E]'command' ] [-- ] [programfile ] [argument ]...
For more information on these options, you can runperldoc perlrun.
Theperldoc program gives you access to all the documentation that comes with Perl. You can get more documentation, tutorials and community support online athttps://www.perl.org/.
If you're new to Perl, you should start by runningperldoc perlintro, which is a general intro for beginners and provides some background to help you navigate the rest of Perl's extensive documentation. Runperldoc perldoc to learn more things you can do withperldoc.
For ease of access, the Perl manual has been split up into several sections.
perl Perl overview (this section)perlintro Perl introduction for beginnersperlrun Perl execution and optionsperltoc Perl documentation table of contentsperlreftut Perl references short introductionperldsc Perl data structures introperllol Perl data structures: arrays of arraysperlrequick Perl regular expressions quick startperlretut Perl regular expressions tutorialperlootut Perl OO tutorial for beginnersperlperf Perl Performance and Optimization Techniquesperlstyle Perl style guideperlcheat Perl cheat sheetperltrap Perl traps for the unwaryperldebtut Perl debugging tutorialperlfaq Perl frequently asked questionsperlfaq1 General Questions About Perlperlfaq2 Obtaining and Learning about Perlperlfaq3 Programming Toolsperlfaq4 Data Manipulationperlfaq5 Files and Formatsperlfaq6 Regexesperlfaq7 Perl Language Issuesperlfaq8 System Interactionperlfaq9 Networkingperlsyn Perl syntax: declarations, statements, commentsperldata Perl data structuresperlop Perl expressions: operators, precedence, string literalsperlsub Perl subroutinesperlfunc Perl built-in functionsperlopentut Perl open() tutorialperlpacktut Perl pack() and unpack() tutorialperlpod Perl plain old documentationperlpodspec Perl plain old documentation format specificationperldocstyle Perl style guide for core docsperlpodstyle Perl POD style guideperldiag Perl diagnostic messagesperldeprecation Perl deprecationsperllexwarn Perl warnings and their controlperldebug Perl debuggingperlvar Perl predefined variablesperlre Perl regular expressions, the rest of the storyperlrebackslash Perl regular expression backslash sequencesperlrecharclass Perl regular expression character classesperlreref Perl regular expressions quick referenceperlref Perl references, the rest of the storyperlform Perl formatsperlobj Perl objectsperltie Perl objects hidden behind simple variablesperldbmfilter Perl DBM filtersperlclass Perl class syntaxperlipc Perl interprocess communicationperlfork Perl fork() informationperlnumber Perl number semanticsperlthrtut Perl threads tutorialperlport Perl portability guideperllocale Perl locale supportperluniintro Perl Unicode introductionperlunicode Perl Unicode supportperlunicook Perl Unicode cookbookperlunifaq Perl Unicode FAQperluniprops Index of Unicode properties in Perlperlunitut Perl Unicode tutorialperlebcdic Considerations for running Perl on EBCDIC platformsperlsec Perl securityperlsecpolicy Perl security report handling policyperlmod Perl modules: how they workperlmodlib Perl modules: how to write and useperlmodstyle Perl modules: how to write modules with styleperlmodinstall Perl modules: how to install from CPANperlnewmod Perl modules: preparing a new module for distributionperlpragma Perl modules: writing a user pragmaperlutil utilities packaged with the Perl distributionperlfilter Perl source filtersperldtrace Perl's support for DTraceperlglossary Perl Glossaryperlembed Perl ways to embed perl in your C or C++ applicationperldebguts Perl debugging guts and tipsperlxstut Perl XS tutorialperlxs Perl XS application programming interfaceperlxstypemap Perl XS C/Perl type conversion toolsperlclib Interacting with standard C library functionsperlguts Perl internal functions for those doing extensionsperlcall Perl calling conventions from Cperlmroapi Perl method resolution plugin interfaceperlreapi Perl regular expression plugin interfaceperlreguts Perl regular expression engine internalsperlclassguts Internals of class syntaxperlapi Perl API listing (autogenerated)perlintern Perl internal functions (autogenerated)perliol C API for Perl's implementation of IO in Layersperlapio Perl internal IO abstraction interfaceperlhack Perl hackers guideperlsource Guide to the Perl source treeperlinterp Overview of the Perl interpreter source and how it worksperlhacktut Walk through the creation of a simple C code patchperlhacktips Tips for Perl core C code hackingperlpolicy Perl development policiesperlgov Perl Rules of Governanceperlgit Using git with the Perl repositoryperlhist Perl history recordsperldelta Perl changes since previous versionperl5416delta Perl changes in version 5.41.6perl5415delta Perl changes in version 5.41.5perl5414delta Perl changes in version 5.41.4perl5413delta Perl changes in version 5.41.3perl5412delta Perl changes in version 5.41.2perl5411delta Perl changes in version 5.41.1perl5410delta Perl changes in version 5.41.0perl5400delta Perl changes in version 5.40.0perl5382delta Perl changes in version 5.38.2perl5381delta Perl changes in version 5.38.1perl5380delta Perl changes in version 5.38.0perl5363delta Perl changes in version 5.36.3perl5362delta Perl changes in version 5.36.2perl5361delta Perl changes in version 5.36.1perl5360delta Perl changes in version 5.36.0perl5343delta Perl changes in version 5.34.3perl5342delta Perl changes in version 5.34.2perl5341delta Perl changes in version 5.34.1perl5340delta Perl changes in version 5.34.0perl5321delta Perl changes in version 5.32.1perl5320delta Perl changes in version 5.32.0perl5303delta Perl changes in version 5.30.3perl5302delta Perl changes in version 5.30.2perl5301delta Perl changes in version 5.30.1perl5300delta Perl changes in version 5.30.0perl5283delta Perl changes in version 5.28.3perl5282delta Perl changes in version 5.28.2perl5281delta Perl changes in version 5.28.1perl5280delta Perl changes in version 5.28.0perl5263delta Perl changes in version 5.26.3perl5262delta Perl changes in version 5.26.2perl5261delta Perl changes in version 5.26.1perl5260delta Perl changes in version 5.26.0perl5244delta Perl changes in version 5.24.4perl5243delta Perl changes in version 5.24.3perl5242delta Perl changes in version 5.24.2perl5241delta Perl changes in version 5.24.1perl5240delta Perl changes in version 5.24.0perl5224delta Perl changes in version 5.22.4perl5223delta Perl changes in version 5.22.3perl5222delta Perl changes in version 5.22.2perl5221delta Perl changes in version 5.22.1perl5220delta Perl changes in version 5.22.0perl5203delta Perl changes in version 5.20.3perl5202delta Perl changes in version 5.20.2perl5201delta Perl changes in version 5.20.1perl5200delta Perl changes in version 5.20.0perl5184delta Perl changes in version 5.18.4perl5182delta Perl changes in version 5.18.2perl5181delta Perl changes in version 5.18.1perl5180delta Perl changes in version 5.18.0perl5163delta Perl changes in version 5.16.3perl5162delta Perl changes in version 5.16.2perl5161delta Perl changes in version 5.16.1perl5160delta Perl changes in version 5.16.0perl5144delta Perl changes in version 5.14.4perl5143delta Perl changes in version 5.14.3perl5142delta Perl changes in version 5.14.2perl5141delta Perl changes in version 5.14.1perl5140delta Perl changes in version 5.14.0perl5125delta Perl changes in version 5.12.5perl5124delta Perl changes in version 5.12.4perl5123delta Perl changes in version 5.12.3perl5122delta Perl changes in version 5.12.2perl5121delta Perl changes in version 5.12.1perl5120delta Perl changes in version 5.12.0perl5101delta Perl changes in version 5.10.1perl5100delta Perl changes in version 5.10.0perl589delta Perl changes in version 5.8.9perl588delta Perl changes in version 5.8.8perl587delta Perl changes in version 5.8.7perl586delta Perl changes in version 5.8.6perl585delta Perl changes in version 5.8.5perl584delta Perl changes in version 5.8.4perl583delta Perl changes in version 5.8.3perl582delta Perl changes in version 5.8.2perl581delta Perl changes in version 5.8.1perl58delta Perl changes in version 5.8.0perl561delta Perl changes in version 5.6.1perl56delta Perl changes in version 5.6perl5005delta Perl changes in version 5.005perl5004delta Perl changes in version 5.004perlbook Perl book informationperlcommunity Perl community informationperldoc Look up Perl documentation in Pod formatperlexperiment A listing of experimental features in Perlperlartistic Perl Artistic Licenseperlgpl GNU General Public Licenseperlcn Perl for Simplified Chinese (in UTF-8)perljp Perl for Japanese (in EUC-JP)perlko Perl for Korean (in EUC-KR)perltw Perl for Traditional Chinese (in Big5)perlaix Perl notes for AIXperlamiga Perl notes for AmigaOSperlandroid Perl notes for Androidperlbs2000 Perl notes for POSIX-BC BS2000perlcygwin Perl notes for Cygwinperlfreebsd Perl notes for FreeBSDperlhaiku Perl notes for Haikuperlhpux Perl notes for HP-UXperlhurd Perl notes for Hurdperlirix Perl notes for Irixperllinux Perl notes for Linuxperlmacosx Perl notes for Mac OS Xperlopenbsd Perl notes for OpenBSDperlos2 Perl notes for OS/2perlos390 Perl notes for OS/390perlos400 Perl notes for OS/400perlplan9 Perl notes for Plan 9perlqnx Perl notes for QNXperlriscos Perl notes for RISC OSperlsolaris Perl notes for Solarisperlsynology Perl notes for Synologyperltru64 Perl notes for Tru64perlvms Perl notes for VMSperlvos Perl notes for Stratus VOSperlwin32 Perl notes for WindowsperlbootperlbotperlrepositoryperltodoperltoocperltootOn a Unix-like system, these documentation files will usually also be available as manpages for use with theman program.
Some documentation is not available as man pages, so if a cross-reference is not found by man, try it withperldoc. Perldoc can also take you directly to documentation for functions (with the-f switch). Seeperldoc --help (orperldoc perldoc orman perldoc) for other helpful optionsperldoc has to offer.
In general, if something strange has gone wrong with your program and you're not sure where you should look for help, try making your code comply withusestrict andusewarnings. These will often point out exactly where the trouble is.
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). It combines (in the author's opinion, anyway) some of the best features ofsed,awk, andsh, making it familiar and easy to use for Unix users to whip up quick solutions to annoying problems. Its general-purpose programming facilities support procedural, functional, and object-oriented programming paradigms, making Perl a comfortable language for the long haul on major projects, whatever your bent.
Perl's roots in text processing haven't been forgotten over the years. It still boasts some of the most powerful regular expressions to be found anywhere, and its support for Unicode text is world-class. It handles all kinds of structured text, too, through an extensive collection of extensions. Those libraries, collected in the CPAN, provide ready-made solutions to an astounding array of problems. When they haven't set the standard themselves, they steal from the best -- just like Perl itself.
Perl is available for most operating systems, including virtually all Unix-like platforms. See"Supported Platforms" in perlport for a listing.
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 .
"@INC" locations of perl libraries"@INC" above is a reference to the built-in variable of the same name; seeperlvar for more information.
the Perl homepage
Perl articles
the Comprehensive Perl Archive
the Perl Mongers
Using theusestrict pragma ensures that all variables are properly declared and prevents other misuses of legacy Perl features. These are enabled by default within the scope ofuse v5.12 (or higher).
Theusewarnings pragma produces some lovely diagnostics. It is enabled by default when you sayuse v5.35 (or higher). One can also use the-w flag, but its use is normally discouraged, because it gets applied to all executed Perl code, including that not under your control.
Seeperldiag for explanations of all Perl's diagnostics. Theusediagnostics 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-e switches, each-e is counted as one line.)
Setuid scripts have additional constraints that can produce error messages such as "Insecure dependency". Seeperlsec.
Did we mention that you should definitely consider using theusewarnings pragma?
The behavior implied by theusewarnings pragma 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 submit your bug reports (be sure to include full configuration information as output by the myconfig program in the perl source tree, or byperl -V) tohttps://github.com/Perl/perl5/issues.
Perl actually stands for Pathologically Eclectic Rubbish Lister, but don't tell anyone I said that.
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.
Perldoc Browser is maintained by Dan Book (DBOOK). Please contact him via theGitHub issue tracker oremail regarding any issues with the site itself, search, or rendering of documentation.
The Perl documentation is maintained by the Perl 5 Porters in the development of Perl. Please contact them via thePerl issue tracker, themailing list, orIRC to report any issues with the contents or format of the documentation.