S<[ B<-i>[I<extension>] ]>
S<[ [B<-e>|B<-E>] I<'command'> ] [ B<--> ] [ I<programfile> ] [ I<argument> ]...>
+For more information on these options, you can run C<perldoc perlrun>.
+
=head1 GETTING HELP
The F<perldoc> program gives you access to all the documentation that comes
flag =ro perlcn perljp perlko perltw
flag = perlvms
-path perlfaq.* cpan/perlfaq/lib/
-path perlglossary cpan/perlfaq/lib/
-path perlxs(?:tut)? dist/ExtUtils-ParseXS/lib/
-path perldoc cpan/Pod-Perldoc/lib/
+path perlfaq.* cpan/perlfaq/lib/
+path perlglossary cpan/perlfaq/lib/
+path perlxs(?:tut|typemap)? dist/ExtUtils-ParseXS/lib/
+path perldoc cpan/Pod-Perldoc/
-aux a2p c2ph h2ph h2xs perlbug pl2pm pod2html pod2man s2p splain xsubpp
+aux c2ph h2ph h2xs perlbug pl2pm pod2html pod2man splain xsubpp
=end buildtoc
perl Perl overview (this section)
perlintro Perl introduction for beginners
+ perlrun Perl execution and options
perltoc Perl documentation table of contents
=head2 Tutorials
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
perllocale Perl locale support
perluniintro Perl Unicode introduction
perlunicode Perl Unicode support
+ perlunicook Perl Unicode cookbook
perlunifaq Perl Unicode FAQ
- perluniprops Index of Unicode Version 6.0.0 properties in Perl
+ perluniprops Index of Unicode properties in Perl
perlunitut Perl Unicode tutorial
perlebcdic Considerations for running Perl on EBCDIC platforms
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
perlbook Perl book information
perlcommunity Perl community information
- perltodo Perl things to do
perldoc Look up Perl documentation in Pod format
perlhist Perl history records
perldelta Perl changes since previous version
- perl5157delta Perl changes in version 5.15.7
- perl5156delta Perl changes in version 5.15.6
- perl5155delta Perl changes in version 5.15.5
- perl5154delta Perl changes in version 5.15.4
- perl5153delta Perl changes in version 5.15.3
- perl5152delta Perl changes in version 5.15.2
- perl5151delta Perl changes in version 5.15.1
- perl5150delta Perl changes in version 5.15.0
+ perl5218delta Perl changes in version 5.21.8
+ perl5217delta Perl changes in version 5.21.7
+ perl5216delta Perl changes in version 5.21.6
+ perl5215delta Perl changes in version 5.21.5
+ perl5214delta Perl changes in version 5.21.4
+ perl5213delta Perl changes in version 5.21.3
+ perl5212delta Perl changes in version 5.21.2
+ perl5211delta Perl changes in version 5.21.1
+ perl5210delta Perl changes in version 5.21.0
+ perl5202delta Perl changes in version 5.20.2
+ perl5201delta Perl changes in version 5.20.1
+ perl5200delta Perl changes in version 5.20.0
+ perl5184delta Perl changes in version 5.18.4
+ perl5182delta Perl changes in version 5.18.2
+ perl5181delta Perl changes in version 5.18.1
+ perl5180delta Perl changes in version 5.18.0
+ perl5163delta Perl changes in version 5.16.3
+ perl5162delta Perl changes in version 5.16.2
+ perl5161delta Perl changes in version 5.16.1
+ perl5160delta Perl changes in version 5.16.0
+ perl5144delta Perl changes in version 5.14.4
+ 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
+ perl5125delta Perl changes in version 5.12.5
perl5124delta Perl changes in version 5.12.4
perl5123delta Perl changes in version 5.12.3
perl5122delta Perl changes in version 5.12.2
perlaix Perl notes for AIX
perlamiga Perl notes for AmigaOS
- perlbeos Perl notes for BeOS
+ perlandroid Perl notes for Android
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
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
perlriscos Perl notes for RISC OS
perlsolaris Perl notes for Solaris
perlsymbian Perl notes for Symbian
+ perlsynology Perl notes for Synology
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
perlboot
perlbot
+ perlrepository
+ perltodo
perltooc
perltoot
On a Unix-like system, these documentation files will usually also be
available as manpages for use with the F<man> program.
+Some documentation is not available as man pages, so if a
+cross-reference is not found by man, try it with L<perldoc>. Perldoc can
+also take you directly to documentation for functions (with the B<-f>
+switch). See C<perldoc --help> (or C<perldoc perldoc> or C<man perldoc>)
+for other helpful options L<perldoc> 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 the B<-w> switch first. It will
-often point out exactly where the trouble is.
+not sure where you should look for help, try making your code comply with
+B<use strict> and B<use warnings>. These will often point out exactly
+where the trouble is.
=head1 DESCRIPTION
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<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.
+complete) rather than beautiful (tiny, elegant, minimal). It combines
+(in the author's opinion, anyway) some of the best features of B<sed>,
+B<awk>, and B<sh>, 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.
=head1 AVAILABILITY
=head1 DIAGNOSTICS
-The C<use warnings> pragma (and the B<-w> switch) produces some
-lovely diagnostics.
+Using the C<use strict> pragma ensures that all variables are properly
+declared and prevents other misuses of legacy Perl features.
+
+The C<use warnings> pragma produces some lovely diagnostics. One can
+also use the B<-w> flag, but its use is normally discouraged, because
+it gets applied to all executed Perl code, including that not under
+your control.
See L<perldiag> for explanations of all Perl's diagnostics. The C<use
diagnostics> pragma automatically turns Perl's normally terse warnings
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?
+Did we mention that you should definitely consider using the B<use warnings>
+pragma?
=head1 BUGS
-The B<-w> switch is not mandatory.
+The behavior implied by the B<use warnings> 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
https://perl5.git.perl.org / perl5.git / blobdiff