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Updated: July 2017
 
 

perl(1)

Name

perl - Practical Extraction and Report Language

Synopsis

perl [-sTuU] [-hv] [-V [: configvar]] [-cw] 
     [-d [: debugger]] [-D [number/list]] [-pna] 
     [-F pattern] [-l [octal]] [-0 [octal]] [-I dir] 
     [-m [-] module] [-M [-] 'module...'] [-P] [-S] 
     [-x [dir]] [-i [extension]] [-e 'command'] [-–] 
     [programfile] [argument]...

Description

For ease of access, the Perl manual has been split up into the following sections.

OVERVIEW

perl                Perl overview (this section)
perlintro           Perl introduction for beginners
perltoc             Perl documentation table of contents

TUTORIALS

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
perlboot            Perl OO tutorial for beginners
perltoot            Perl OO tutorial, part 1
perltooc            Perl OO tutorial, part 2
perlbot             Perl OO tricks and examples
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

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
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
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
perlothrtut         Old Perl threads tutorial
perlport            Perl portability guide
perllocale          Perl locale support
perluniintro        Perl Unicode introduction
perlunicode         Perl Unicode support
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
perlutil            utilities packaged with the Perl distribution
perlcompile         Perl compiler suite intro
perlfilter          Perl source filters

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
perlclib            Internal replacements for standard C library functions
perlguts            Perl internal functions for those doing extensions
perlcall            Perl calling conventions from C
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

MISCELLANEOUS

perlbook            Perl book information
perltodo            Perl things to do
perldoc             Look up Perl documentation in Pod format
perlhist            Perl history records
perldelta           Perl changes since previous version
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
perl573delta        Perl changes in version 5.7.3
perl572delta        Perl changes in version 5.7.2
perl571delta        Perl changes in version 5.7.1
perl570delta        Perl changes in version 5.7.0
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
perlartistic        Perl Artistic License
perlgpl             GNU General Public License

LANGUAGE-SPECIFIC

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)

PLATFORM-SPECIFIC

perlsolaris         Perl notes for Solaris

Platform-Specific

If you're new to Perl, you should start with perlintro, which is a general intro for beginners and provides some background to help you navigate the rest of Perl's extensive documentation. For ease of access, the Perl manual has been split up into several sections.

The manpages listed above are installed in the /usr/perl5/man/ directory.

Extensive additional documentation for Perl modules is available. This additional documentation is in the /usr/perl5/man directory. Some of this additional documentation is distributed standard with Perl, but you'll also find documentation for any customer-installed third-party modules there.

You can view Perl's documentation with man(1) by including /usr/perl5/man in the MANPATH environment variable. Notice that running catman(1M) on the Perl manual pages is not supported. For other Solaris-specific details, see the NOTES section below.

You can also use the supplied /usr/perl5/bin/perldoc script to view Perl information.

If something strange has gone wrong with your program and you're not sure where you should look for help, try the –w switch first. It will often point out exactly where the trouble is.

Perl is a language optimized for scanning arbitrary text files, extracting information from those text files, and printing reports based on that information. It's also a good language for many system 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 best features of C, sed, awk, and sh, so people familiar with those languages should have little difficulty with it. (Language historians will also note some vestiges of 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 can also deal with binary data, and can make dbm files look like hashes. Setuid Perl scripts are safer than C programs through a dataflow tracing mechanism that prevents many stupid security holes.

If you have a problem that would ordinarily use sed or awk or sh, but it exceeds their capabilities or must run a little faster, and you don't want to write the silly thing in C, then Perl may be for you. There are also translators to turn your sed and awk scripts into Perl scripts.

But wait, there's more...

Begun in 1993 (see perlhist), Perl version 5 is nearly a complete rewrite that provides the following additional benefits:

  • Modularity and reusability using innumerable modules Described in perlmod, perlmodlib, and perlmodinstall.

  • Embeddable and extensible Described in perlembed, perlxstut, perlxs, perlcall, perlguts, and xsubpp.

  • Roll-your-own magic variables (including multiple simultaneous DBM implementations). Described in perltie and AnyDBM_File.

  • Subroutines can now be overridden, autoloaded, and prototyped. Described in perlsub.

  • Arbitrarily nested data structures and anonymous functions. Described in perlreftut, perlref, perldsc, and perllol.

  • Object-oriented programming. Described in perlobj, perlboot, perltoot, perltooc, and perlbot.

  • Support for light-weight processes (threads). Described in perlthrtut and threads.

  • Support for Unicode, internationalization, and localization Described in perluniintro, perllocale and Locale::Maketext.

  • Lexical scoping. Described in perlsub.

  • Regular expression enhancements. Described in perlre, with additional examples in perlop.

  • Enhanced debugger and interactive Perl environment, with integrated editor support. Described in perldebtut, perldebug and perldebguts.

  • POSIX 1003.1 compliant library Described in POSIX.

Okay, that's definitely enough hype.

Environment Variables

The Perl shipped with Solaris is installed under /usr/perl5 rather than the default /usr/local location. This is so that it can coexist with a customer-installed Perl in the default /usr/local location.

Any additional modules that you choose to install will be placed in the /usr/perl5/site_perl/5.8.4 directory. The /usr/perl5/vendor_perl directory is reserved for SMI-provided modules.

Notice that the Perl utility scripts such as perldoc and perlbug are in the /usr/perl5/bin directory, so if you wish to use them you need to include /usr/perl5/bin in your PATH environment variable.

See also the perlrun mapage.

AUTHOR

Larry Wall, 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 .

Files

"@INC"

Locations of Perl libraries

Attributes

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Availability
runtime/perl-584, runtime/perl-584/extra, runtime/perl-584/manual, SUNWpl5u, SUNWpl5v SUNWpl5p, SUNWpl5m
See below.
Interface Stability
See below.

Perl is available for most operating systems, including virtually all Unix-like platforms. See "Supported Platforms" in perlport for a listing.

The Script interface, the XSUB interface, and the Directory layout are Committed. The Binary interface is Uncommitted.

See Also

a2p

awk to perl translator

s2p

sed to perl translator

http://www.perl.com

Perl home page

http://www.perl.com/CPAN

The Comprehensive Perl Archive

http://www.perl.org

Perl Mongers (Perl user groups)

Diagnostics

The `use warnings' pragma (and the –w switch) produce some lovely diagnostics.

See perldiag for explanations of all Perl's diagnostics. The `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 –e switches, each –e is counted as one line.)

Setuid scripts have additional constraints that can produce error messages such as "Insecure dependency". See perlsec.

Did we mention that you should definitely consider using the –w switch?

Notes

Perl 5.8.4 has been built to be largefile-aware and to use 64–bit integers, although the interpreter itself is a 32–bit application (LP32). To view detailed configuration information, use perl –V and perlbug –dv.

If you wish to build and install add-on modules from CPAN using gcc, you can do so using the /usr/perl5/5.8.4/bin/perlgcc script – see perlgcc(1) for details.

If you wish to build and install your own version of Perl, you should NOT remove the 5.8.4 version of perl under /usr/perl5, as it is required by several system utilities. The Perl package names are as follows:

SUNWperl584core    Perl 5.8.4 (Core files)
SUNWperl584usr     Perl 5.8.4 (Non-core files)
SUNWperl584man     Perl 5.8.4 (Manual pages)

Solaris 10 also ships with the 5.6.1 version of Perl that was included in Solaris 9. If you are upgrading your system and wish to continue to use Perl 5.6.1 as the default Perl version you should refer to the perlsolaris manpage for details of how to do this. Note that you should upgrade your installation to use Perl 5.8.4 as soon as is practicable, as Perl 5.6.1 may be removed in a future release.

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.

Bugs

The –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 `perl –V') to perlbug@perl.org . If you've succeeded in compiling perl, the perlbug script in the 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.