| perl - Practical Extraction and Report Language |
perl - Practical Extraction and Report Language
perl [ -sTuU ] [ -hv ] [ -V[:configvar] ] [ -cw ] [ -d[:debugger] ] [ -D[number/list] ] [ -pna ] [ -Fpattern ] [ -l[octal] ] [ -0[octal] ] [ -Idir ] [ -m[-]module ] [ -M[-]'module...' ] [ -P ] [ -S ] [ -x[dir] ] [ -i[extension] ] [ -e 'command' ] [ -- ] [ programfile ] [ argument ]...
If you're new to Perl, you should start with the perlintro manpage, 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.
perl Perl overview (this section)
file://D:/temp/Perl/html/lib/Pod/perlintro.pod:">perlintro Perl introduction for beginners
file://D:/temp/Perl/html/lib/Pod/perltoc.pod:">perltoc Perl documentation table of contents
file://D:/temp/Perl/html/lib/Pod/perlreftut.pod:">perlreftut Perl references short introduction
file://D:/temp/Perl/html/lib/Pod/perldsc.pod:">perldsc Perl data structures intro
file://D:/temp/Perl/html/lib/Pod/perllol.pod:">perllol Perl data structures: arrays of arrays
file://D:/temp/Perl/html/lib/Pod/perlrequick.pod:">perlrequick Perl regular expressions quick start
file://D:/temp/Perl/html/lib/Pod/perlretut.pod:">perlretut Perl regular expressions tutorial
file://D:/temp/Perl/html/lib/Pod/perlboot.pod:">perlboot Perl OO tutorial for beginners
file://D:/temp/Perl/html/lib/Pod/perltoot.pod:">perltoot Perl OO tutorial, part 1
file://D:/temp/Perl/html/lib/Pod/perltooc.pod:">perltooc Perl OO tutorial, part 2
file://D:/temp/Perl/html/lib/Pod/perlbot.pod:">perlbot Perl OO tricks and examples
file://D:/temp/Perl/html/lib/Pod/perlstyle.pod:">perlstyle Perl style guide
file://D:/temp/Perl/html/lib/Pod/perltrap.pod:">perltrap Perl traps for the unwary
file://D:/temp/Perl/html/lib/Pod/perldebtut.pod:">perldebtut Perl debugging tutorial
file://D:/temp/Perl/html/lib/Pod/perlfaq.pod:">perlfaq Perl frequently asked questions
file://D:/temp/Perl/html/lib/Pod/perlfaq1.pod:">perlfaq1 General Questions About Perl
file://D:/temp/Perl/html/lib/Pod/perlfaq2.pod:">perlfaq2 Obtaining and Learning about Perl
file://D:/temp/Perl/html/lib/Pod/perlfaq3.pod:">perlfaq3 Programming Tools
file://D:/temp/Perl/html/lib/Pod/perlfaq4.pod:">perlfaq4 Data Manipulation
file://D:/temp/Perl/html/lib/Pod/perlfaq5.pod:">perlfaq5 Files and Formats
file://D:/temp/Perl/html/lib/Pod/perlfaq6.pod:">perlfaq6 Regexes
file://D:/temp/Perl/html/lib/Pod/perlfaq7.pod:">perlfaq7 Perl Language Issues
file://D:/temp/Perl/html/lib/Pod/perlfaq8.pod:">perlfaq8 System Interaction
file://D:/temp/Perl/html/lib/Pod/perlfaq9.pod:">perlfaq9 Networking
file://D:/temp/Perl/html/lib/Pod/perlsyn.pod:">perlsyn Perl syntax
file://D:/temp/Perl/html/lib/Pod/perldata.pod:">perldata Perl data structures
file://D:/temp/Perl/html/lib/Pod/perlop.pod:">perlop Perl operators and precedence
file://D:/temp/Perl/html/lib/Pod/perlsub.pod:">perlsub Perl subroutines
file://D:/temp/Perl/html/lib/Pod/perlfunc.pod:">perlfunc Perl built-in functions
file://D:/temp/Perl/html/lib/Pod/perlopentut.pod:">perlopentut Perl open() tutorial
file://D:/temp/Perl/html/lib/Pod/perlpacktut.pod:">perlpacktut Perl pack() and unpack() tutorial
file://D:/temp/Perl/html/lib/Pod/perlpod.pod:site/lib/perlpod.pod:">perlpod Perl plain old documentation
file://D:/temp/Perl/html/lib/Pod/perlpodspec.pod:site/lib/perlpodspec.pod:">perlpodspec Perl plain old documentation format specification
file://D:/temp/Perl/html/lib/Pod/perlrun.pod:">perlrun Perl execution and options
file://D:/temp/Perl/html/lib/Pod/perldiag.pod:">perldiag Perl diagnostic messages
file://D:/temp/Perl/html/lib/Pod/perllexwarn.pod:">perllexwarn Perl warnings and their control
file://D:/temp/Perl/html/lib/Pod/perldebug.pod:">perldebug Perl debugging
file://D:/temp/Perl/html/lib/Pod/perlvar.pod:">perlvar Perl predefined variables
file://D:/temp/Perl/html/lib/Pod/perlre.pod:">perlre Perl regular expressions, the rest of the story
file://D:/temp/Perl/html/lib/Pod/perlref.pod:">perlref Perl references, the rest of the story
file://D:/temp/Perl/html/lib/Pod/perlform.pod:">perlform Perl formats
file://D:/temp/Perl/html/lib/Pod/perlobj.pod:">perlobj Perl objects
file://D:/temp/Perl/html/lib/Pod/perltie.pod:">perltie Perl objects hidden behind simple variables
file://D:/temp/Perl/html/lib/Pod/perldbmfilter.pod:">perldbmfilter Perl DBM filters
file://D:/temp/Perl/html/lib/Pod/perlipc.pod:">perlipc Perl interprocess communication
file://D:/temp/Perl/html/lib/Pod/perlfork.pod:">perlfork Perl fork() information
file://D:/temp/Perl/html/lib/Pod/perlnumber.pod:">perlnumber Perl number semantics
file://D:/temp/Perl/html/lib/Pod/perlthrtut.pod:">perlthrtut Perl threads tutorial
file://D:/temp/Perl/html/lib/Pod/perlothrtut.pod:">perlothrtut Old Perl threads tutorial
file://D:/temp/Perl/html/lib/Pod/perlport.pod:">perlport Perl portability guide
file://D:/temp/Perl/html/lib/Pod/perllocale.pod:">perllocale Perl locale support
file://D:/temp/Perl/html/lib/Pod/perluniintro.pod:">perluniintro Perl Unicode introduction
file://D:/temp/Perl/html/lib/Pod/perlunicode.pod:">perlunicode Perl Unicode support
file://D:/temp/Perl/html/lib/Pod/perlebcdic.pod:">perlebcdic Considerations for running Perl on EBCDIC platforms
file://D:/temp/Perl/html/lib/Pod/perlsec.pod:">perlsec Perl security
file://D:/temp/Perl/html/lib/Pod/perlmod.pod:">perlmod Perl modules: how they work
file://D:/temp/Perl/html/lib/Pod/perlmodlib.pod:">perlmodlib Perl modules: how to write and use
file://D:/temp/Perl/html/lib/Pod/perlmodstyle.pod:">perlmodstyle Perl modules: how to write modules with style
file://D:/temp/Perl/html/lib/Pod/perlmodinstall.pod:">perlmodinstall Perl modules: how to install from CPAN
file://D:/temp/Perl/html/lib/Pod/perlnewmod.pod:">perlnewmod Perl modules: preparing a new module for distribution
file://D:/temp/Perl/html/lib/Pod/perlutil.pod:">perlutil utilities packaged with the Perl distribution
file://D:/temp/Perl/html/lib/Pod/perlcompile.pod:">perlcompile Perl compiler suite intro
file://D:/temp/Perl/html/lib/Pod/perlfilter.pod:">perlfilter Perl source filters
file://D:/temp/Perl/html/lib/Pod/perlembed.pod:">perlembed Perl ways to embed perl in your C or C++ application
file://D:/temp/Perl/html/lib/Pod/perldebguts.pod:">perldebguts Perl debugging guts and tips
file://D:/temp/Perl/html/lib/Pod/perlxstut.pod:">perlxstut Perl XS tutorial
file://D:/temp/Perl/html/lib/Pod/perlxs.pod:">perlxs Perl XS application programming interface
file://D:/temp/Perl/html/lib/Pod/perlclib.pod:">perlclib Internal replacements for standard C library functions
file://D:/temp/Perl/html/lib/Pod/perlguts.pod:">perlguts Perl internal functions for those doing extensions
file://D:/temp/Perl/html/lib/Pod/perlcall.pod:">perlcall Perl calling conventions from C
file://D:/temp/Perl/html/lib/Pod/perlapi.pod:">perlapi Perl API listing (autogenerated)
file://D:/temp/Perl/html/lib/Pod/perlintern.pod:">perlintern Perl internal functions (autogenerated)
file://D:/temp/Perl/html/lib/Pod/perliol.pod:">perliol C API for Perl's implementation of IO in Layers
file://D:/temp/Perl/html/lib/Pod/perlapio.pod:">perlapio Perl internal IO abstraction interface
file://D:/temp/Perl/html/lib/Pod/perlhack.pod:">perlhack Perl hackers guide
file://D:/temp/Perl/html/lib/Pod/perlbook.pod:">perlbook Perl book information
file://D:/temp/Perl/html/lib/Pod/perltodo.pod:">perltodo Perl things to do
file://D:/temp/Perl/html/lib/Pod/perlhist.pod:">perlhist Perl history records
file://D:/temp/Perl/html/lib/Pod/perldelta.pod:">perldelta Perl changes since previous version
file://D:/temp/Perl/html/lib/Pod/perl572delta.pod:">perl572delta Perl changes in version 5.7.2
file://D:/temp/Perl/html/lib/Pod/perl571delta.pod:">perl571delta Perl changes in version 5.7.1
file://D:/temp/Perl/html/lib/Pod/perl570delta.pod:">perl570delta Perl changes in version 5.7.0
file://D:/temp/Perl/html/lib/Pod/perl561delta.pod:">perl561delta Perl changes in version 5.6.1
file://D:/temp/Perl/html/lib/Pod/perl56delta.pod:">perl56delta Perl changes in version 5.6
file://D:/temp/Perl/html/lib/Pod/perl5005delta.pod:">perl5005delta Perl changes in version 5.005
file://D:/temp/Perl/html/lib/Pod/perl5004delta.pod:">perl5004delta Perl changes in version 5.004
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)
file://D:/temp/Perl/html/lib/Pod/perlaix.pod:">perlaix Perl notes for AIX
file://D:/temp/Perl/html/lib/Pod/perlamiga.pod:">perlamiga Perl notes for AmigaOS
file://D:/temp/Perl/html/lib/Pod/perlapollo.pod:">perlapollo Perl notes for Apollo DomainOS
file://D:/temp/Perl/html/lib/Pod/perlbeos.pod:">perlbeos Perl notes for BeOS
file://D:/temp/Perl/html/lib/Pod/perlbs2000.pod:">perlbs2000 Perl notes for POSIX-BC BS2000
file://D:/temp/Perl/html/lib/Pod/perlce.pod:">perlce Perl notes for WinCE
file://D:/temp/Perl/html/lib/Pod/perlcygwin.pod:">perlcygwin Perl notes for Cygwin
file://D:/temp/Perl/html/lib/Pod/perldgux.pod:">perldgux Perl notes for DG/UX
file://D:/temp/Perl/html/lib/Pod/perldos.pod:">perldos Perl notes for DOS
file://D:/temp/Perl/html/lib/Pod/perlepoc.pod:">perlepoc Perl notes for EPOC
file://D:/temp/Perl/html/lib/Pod/perlfreebsd.pod:">perlfreebsd Perl notes for FreeBSD
file://D:/temp/Perl/html/lib/Pod/perlhpux.pod:">perlhpux Perl notes for HP-UX
file://D:/temp/Perl/html/lib/Pod/perlhurd.pod:">perlhurd Perl notes for Hurd
file://D:/temp/Perl/html/lib/Pod/perlirix.pod:">perlirix Perl notes for Irix
file://D:/temp/Perl/html/lib/Pod/perlmachten.pod:">perlmachten Perl notes for Power MachTen
file://D:/temp/Perl/html/lib/Pod/perlmacos.pod:">perlmacos Perl notes for Mac OS (Classic)
file://D:/temp/Perl/html/lib/Pod/perlmint.pod:">perlmint Perl notes for MiNT
file://D:/temp/Perl/html/lib/Pod/perlmpeix.pod:">perlmpeix Perl notes for MPE/iX
file://D:/temp/Perl/html/lib/Pod/perlnetware.pod:">perlnetware Perl notes for NetWare
file://D:/temp/Perl/html/lib/Pod/perlos2.pod:">perlos2 Perl notes for OS/2
file://D:/temp/Perl/html/lib/Pod/perlos390.pod:">perlos390 Perl notes for OS/390
file://D:/temp/Perl/html/lib/Pod/perlplan9.pod:">perlplan9 Perl notes for Plan 9
file://D:/temp/Perl/html/lib/Pod/perlqnx.pod:">perlqnx Perl notes for QNX
file://D:/temp/Perl/html/lib/Pod/perlsolaris.pod:">perlsolaris Perl notes for Solaris
file://D:/temp/Perl/html/lib/Pod/perltru64.pod:">perltru64 Perl notes for Tru64
file://D:/temp/Perl/html/lib/Pod/perluts.pod:">perluts Perl notes for UTS
file://D:/temp/Perl/html/lib/Pod/perlvmesa.pod:">perlvmesa Perl notes for VM/ESA
file://D:/temp/Perl/html/lib/Pod/perlvms.pod:">perlvms Perl notes for VMS
file://D:/temp/Perl/html/lib/Pod/perlvos.pod:">perlvos Perl notes for Stratus VOS
file://D:/temp/Perl/html/lib/Pod/perlwin32.pod:">perlwin32 Perl 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. The default configuration for perl will place this additional documentation in the /usr/local/lib/perl5/man directory (or else in the man subdirectory of the Perl library directory). Some of this additional documentation is distributed standard with Perl, but you'll also find documentation 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-up
files, or in the MANPATH environment variable. To find out where the
configuration has installed the manpages, type:
perl -V:man.dir
If the directories have a common stem, such as /usr/local/man/man1
and /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 add
both stems.
If that doesn't work for some reason, you can still use the supplied perldoc script to view module information. You might also look into getting a replacement man program.
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 the perlhist manpage), Perl version 5 is nearly a complete rewrite that provides the following additional benefits:
Described in the perlmod manpage, the perlmodlib manpage, and the perlmodinstall manpage.
embeddable and extensibleDescribed in the perlembed manpage, the perlxstut manpage, the perlxs manpage, the perlcall manpage, the perlguts manpage, and xsubpp.
roll-your-own magic variables (including multiple simultaneous DBM implementations)Described in the perltie manpage and the AnyDBM_File manpage.
subroutines can now be overridden, autoloaded, and prototypedDescribed in the perlsub manpage.
arbitrarily nested data structures and anonymous functionsDescribed in the perlreftut manpage, the perlref manpage, the perldsc manpage, and the perllol manpage.
object-oriented programmingDescribed in the perlobj manpage, the perlboot manpage, the perltoot manpage, the perltooc manpage, and the perlbot manpage.
support for light-weight processes (threads)Described in the perlthrtut manpage and the threads manpage.
support for Unicode, internationalization, and localizationDescribed in the perluniintro manpage, the perllocale manpage and the Locale::Maketext manpage.
lexical scopingDescribed in the perlsub manpage.
regular expression enhancementsDescribed in the perlre manpage, with additional examples in the perlop manpage.
enhanced debugger and interactive Perl environment, with integrated editor supportDescribed in the perldebtut manpage, the perldebug manpage and the perldebguts manpage.
POSIX 1003.1 compliant libraryDescribed in the POSIX manpage.
Okay, that's definitely enough hype.
Perl is available for most operating systems, including virtually all Unix-like platforms. See Supported Platforms in the perlport manpage for a listing.
See the perlrun manpage.
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
a2p awk to perl translator s2p sed to perl translator
http://www.perl.com/ the Perl Home Page http://www.cpan.org/ the Comprehensive Perl Archive http://www.perl.org/ Perl Mongers (Perl user groups)
The use warnings pragma (and the -w switch) produces some
lovely diagnostics.
See the perldiag manpage 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 the perlsec manpage.
Did we mention that you should definitely consider using the -w switch?
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.
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.
| perl - Practical Extraction and Report Language |