3 perl - The Perl 5 language interpreter
7 B<perl> S<[ B<-sTtuUWX> ]>
8 S<[ B<-hv> ] [ B<-V>[:I<configvar>] ]>
9 S<[ B<-cw> ] [ B<-d>[B<t>][:I<debugger>] ] [ B<-D>[I<number/list>] ]>
10 S<[ B<-pna> ] [ B<-F>I<pattern> ] [ B<-l>[I<octal>] ] [ B<-0>[I<octal/hexadecimal>] ]>
11 S<[ B<-I>I<dir> ] [ B<-m>[B<->]I<module> ] [ B<-M>[B<->]I<'module...'> ] [ B<-f> ]>
12 S<[ B<-C [I<number/list>] >]>
15 S<[ B<-i>[I<extension>] ]>
16 S<[ [B<-e>|B<-E>] I<'command'> ] [ B<--> ] [ I<programfile> ] [ I<argument> ]...>
18 For more information on these options, you can run C<perldoc perlrun>.
22 The F<perldoc> program gives you access to all the documentation that comes
23 with Perl. You can get more documentation, tutorials and community support
24 online at L<http://www.perl.org/>.
26 If you're new to Perl, you should start by running C<perldoc perlintro>,
27 which is a general intro for beginners and provides some background to help
28 you navigate the rest of Perl's extensive documentation. Run C<perldoc
29 perldoc> to learn more things you can do with F<perldoc>.
31 For ease of access, the Perl manual has been split up into several sections.
35 # This section is parsed by Porting/pod_lib.pl for use by pod/buildtoc etc
37 flag =g perluniprops perlmodlib perlapi perlintern
39 flag =ro perlcn perljp perlko perltw
42 path perlfaq.* cpan/perlfaq/lib/
43 path perlglossary cpan/perlfaq/lib/
44 path perlxs(?:tut|typemap)? dist/ExtUtils-ParseXS/lib/
45 path perldoc cpan/Pod-Perldoc/
47 aux a2p c2ph h2ph h2xs perlbug pl2pm pod2html pod2man s2p splain xsubpp
53 perl Perl overview (this section)
54 perlintro Perl introduction for beginners
55 perlrun Perl execution and options
56 perltoc Perl documentation table of contents
60 perlreftut Perl references short introduction
61 perldsc Perl data structures intro
62 perllol Perl data structures: arrays of arrays
64 perlrequick Perl regular expressions quick start
65 perlretut Perl regular expressions tutorial
67 perlootut Perl OO tutorial for beginners
69 perlperf Perl Performance and Optimization Techniques
71 perlstyle Perl style guide
73 perlcheat Perl cheat sheet
74 perltrap Perl traps for the unwary
75 perldebtut Perl debugging tutorial
77 perlfaq Perl frequently asked questions
78 perlfaq1 General Questions About Perl
79 perlfaq2 Obtaining and Learning about Perl
80 perlfaq3 Programming Tools
81 perlfaq4 Data Manipulation
82 perlfaq5 Files and Formats
84 perlfaq7 Perl Language Issues
85 perlfaq8 System Interaction
88 =head2 Reference Manual
91 perldata Perl data structures
92 perlop Perl operators and precedence
93 perlsub Perl subroutines
94 perlfunc Perl built-in functions
95 perlopentut Perl open() tutorial
96 perlpacktut Perl pack() and unpack() tutorial
97 perlpod Perl plain old documentation
98 perlpodspec Perl plain old documentation format specification
99 perlpodstyle Perl POD style guide
100 perldiag Perl diagnostic messages
101 perllexwarn Perl warnings and their control
102 perldebug Perl debugging
103 perlvar Perl predefined variables
104 perlre Perl regular expressions, the rest of the story
105 perlrebackslash Perl regular expression backslash sequences
106 perlrecharclass Perl regular expression character classes
107 perlreref Perl regular expressions quick reference
108 perlref Perl references, the rest of the story
109 perlform Perl formats
111 perltie Perl objects hidden behind simple variables
112 perldbmfilter Perl DBM filters
114 perlipc Perl interprocess communication
115 perlfork Perl fork() information
116 perlnumber Perl number semantics
118 perlthrtut Perl threads tutorial
120 perlport Perl portability guide
121 perllocale Perl locale support
122 perluniintro Perl Unicode introduction
123 perlunicode Perl Unicode support
124 perlunifaq Perl Unicode FAQ
125 perluniprops Index of Unicode properties in Perl
126 perlunitut Perl Unicode tutorial
127 perlebcdic Considerations for running Perl on EBCDIC platforms
129 perlsec Perl security
131 perlmod Perl modules: how they work
132 perlmodlib Perl modules: how to write and use
133 perlmodstyle Perl modules: how to write modules with style
134 perlmodinstall Perl modules: how to install from CPAN
135 perlnewmod Perl modules: preparing a new module for distribution
136 perlpragma Perl modules: writing a user pragma
138 perlutil utilities packaged with the Perl distribution
140 perlfilter Perl source filters
142 perldtrace Perl's support for DTrace
144 perlglossary Perl Glossary
146 =head2 Internals and C Language Interface
148 perlembed Perl ways to embed perl in your C or C++ application
149 perldebguts Perl debugging guts and tips
150 perlxstut Perl XS tutorial
151 perlxs Perl XS application programming interface
152 perlxstypemap Perl XS C/Perl type conversion tools
153 perlclib Internal replacements for standard C library functions
154 perlguts Perl internal functions for those doing extensions
155 perlcall Perl calling conventions from C
156 perlmroapi Perl method resolution plugin interface
157 perlreapi Perl regular expression plugin interface
158 perlreguts Perl regular expression engine internals
160 perlapi Perl API listing (autogenerated)
161 perlintern Perl internal functions (autogenerated)
162 perliol C API for Perl's implementation of IO in Layers
163 perlapio Perl internal IO abstraction interface
165 perlhack Perl hackers guide
166 perlsource Guide to the Perl source tree
167 perlinterp Overview of the Perl interpreter source and how it works
168 perlhacktut Walk through the creation of a simple C code patch
169 perlhacktips Tips for Perl core C code hacking
170 perlpolicy Perl development policies
171 perlgit Using git with the Perl repository
175 perlbook Perl book information
176 perlcommunity Perl community information
178 perldoc Look up Perl documentation in Pod format
180 perlhist Perl history records
181 perldelta Perl changes since previous version
182 perl5192delta Perl changes in version 5.19.2
183 perl5191delta Perl changes in version 5.19.1
184 perl5190delta Perl changes in version 5.19.0
185 perl5180delta Perl changes in version 5.18.0
186 perl5161delta Perl changes in version 5.16.1
187 perl5162delta Perl changes in version 5.16.2
188 perl5163delta Perl changes in version 5.16.3
189 perl5160delta Perl changes in version 5.16.0
190 perl5144delta Perl changes in version 5.14.4
191 perl5143delta Perl changes in version 5.14.3
192 perl5142delta Perl changes in version 5.14.2
193 perl5141delta Perl changes in version 5.14.1
194 perl5140delta Perl changes in version 5.14.0
195 perl5125delta Perl changes in version 5.12.5
196 perl5124delta Perl changes in version 5.12.4
197 perl5123delta Perl changes in version 5.12.3
198 perl5122delta Perl changes in version 5.12.2
199 perl5121delta Perl changes in version 5.12.1
200 perl5120delta Perl changes in version 5.12.0
201 perl5101delta Perl changes in version 5.10.1
202 perl5100delta Perl changes in version 5.10.0
203 perl589delta Perl changes in version 5.8.9
204 perl588delta Perl changes in version 5.8.8
205 perl587delta Perl changes in version 5.8.7
206 perl586delta Perl changes in version 5.8.6
207 perl585delta Perl changes in version 5.8.5
208 perl584delta Perl changes in version 5.8.4
209 perl583delta Perl changes in version 5.8.3
210 perl582delta Perl changes in version 5.8.2
211 perl581delta Perl changes in version 5.8.1
212 perl58delta Perl changes in version 5.8.0
213 perl561delta Perl changes in version 5.6.1
214 perl56delta Perl changes in version 5.6
215 perl5005delta Perl changes in version 5.005
216 perl5004delta Perl changes in version 5.004
218 perlexperiment A listing of experimental features in Perl
220 perlartistic Perl Artistic License
221 perlgpl GNU General Public License
223 =head2 Language-Specific
225 =for buildtoc flag +r
227 perlcn Perl for Simplified Chinese (in EUC-CN)
228 perljp Perl for Japanese (in EUC-JP)
229 perlko Perl for Korean (in EUC-KR)
230 perltw Perl for Traditional Chinese (in Big5)
232 =head2 Platform-Specific
234 perlaix Perl notes for AIX
235 perlamiga Perl notes for AmigaOS
236 perlbs2000 Perl notes for POSIX-BC BS2000
237 perlce Perl notes for WinCE
238 perlcygwin Perl notes for Cygwin
239 perldos Perl notes for DOS
240 perlfreebsd Perl notes for FreeBSD
241 perlhaiku Perl notes for Haiku
242 perlhpux Perl notes for HP-UX
243 perlhurd Perl notes for Hurd
244 perlirix Perl notes for Irix
245 perllinux Perl notes for Linux
246 perlmacos Perl notes for Mac OS (Classic)
247 perlmacosx Perl notes for Mac OS X
248 perlnetware Perl notes for NetWare
249 perlopenbsd Perl notes for OpenBSD
250 perlos2 Perl notes for OS/2
251 perlos390 Perl notes for OS/390
252 perlos400 Perl notes for OS/400
253 perlplan9 Perl notes for Plan 9
254 perlqnx Perl notes for QNX
255 perlriscos Perl notes for RISC OS
256 perlsolaris Perl notes for Solaris
257 perlsymbian Perl notes for Symbian
258 perltru64 Perl notes for Tru64
259 perlvms Perl notes for VMS
260 perlvos Perl notes for Stratus VOS
261 perlwin32 Perl notes for Windows
263 =for buildtoc flag -r
265 =head2 Stubs for Deleted Documents
273 =for buildtoc __END__
275 On a Unix-like system, these documentation files will usually also be
276 available as manpages for use with the F<man> program.
278 Some documentation is not available as man pages, so if a
279 cross-reference is not found by man, try it with L<perldoc>. Perldoc can
280 also take you directly to documentation for functions (with the B<-f>
281 switch). See C<perldoc --help> (or C<perldoc perldoc> or C<man perldoc>)
282 for other helpful options L<perldoc> has to offer.
284 In general, if something strange has gone wrong with your program and you're
285 not sure where you should look for help, try making your code comply with
286 B<use strict> and B<use warnings>. These will often point out exactly
287 where the trouble is.
291 Perl officially stands for Practical Extraction and Report Language,
292 except when it doesn't.
294 Perl was originally a language optimized for scanning arbitrary
295 text files, extracting information from those text files, and printing
296 reports based on that information. It quickly became a good language
297 for many system management tasks. Over the years, Perl has grown into
298 a general-purpose programming language. It's widely used for everything
299 from quick "one-liners" to full-scale application development.
301 The language is intended to be practical (easy to use, efficient,
302 complete) rather than beautiful (tiny, elegant, minimal). It combines
303 (in the author's opinion, anyway) some of the best features of B<sed>,
304 B<awk>, and B<sh>, making it familiar and easy to use for Unix users to
305 whip up quick solutions to annoying problems. Its general-purpose
306 programming facilities support procedural, functional, and
307 object-oriented programming paradigms, making Perl a comfortable
308 language for the long haul on major projects, whatever your bent.
310 Perl's roots in text processing haven't been forgotten over the years.
311 It still boasts some of the most powerful regular expressions to be
312 found anywhere, and its support for Unicode text is world-class. It
313 handles all kinds of structured text, too, through an extensive
314 collection of extensions. Those libraries, collected in the CPAN,
315 provide ready-made solutions to an astounding array of problems. When
316 they haven't set the standard themselves, they steal from the best
317 -- just like Perl itself.
321 Perl is available for most operating systems, including virtually
322 all Unix-like platforms. See L<perlport/"Supported Platforms">
331 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
333 If your Perl success stories and testimonials may be of help to others
334 who wish to advocate the use of Perl in their applications,
335 or if you wish to simply express your gratitude to Larry and the
336 Perl developers, please write to perl-thanks@perl.org .
340 "@INC" locations of perl libraries
344 http://www.perl.org/ the Perl homepage
345 http://www.perl.com/ Perl articles (O'Reilly)
346 http://www.cpan.org/ the Comprehensive Perl Archive
347 http://www.pm.org/ the Perl Mongers
351 Using the C<use strict> pragma ensures that all variables are properly
352 declared and prevents other misuses of legacy Perl features.
354 The C<use warnings> pragma produces some lovely diagnostics. One can
355 also use the B<-w> flag, but its use is normally discouraged, because
356 it gets applied to all executed Perl code, including that not under
359 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
360 diagnostics> pragma automatically turns Perl's normally terse warnings
361 and errors into these longer forms.
363 Compilation errors will tell you the line number of the error, with an
364 indication of the next token or token type that was to be examined.
365 (In a script passed to Perl via B<-e> switches, each
366 B<-e> is counted as one line.)
368 Setuid scripts have additional constraints that can produce error
369 messages such as "Insecure dependency". See L<perlsec>.
371 Did we mention that you should definitely consider using the B<use warnings>
376 The behavior implied by the B<use warnings> pragma is not mandatory.
378 Perl is at the mercy of your machine's definitions of various
379 operations such as type casting, atof(), and floating-point
380 output with sprintf().
382 If your stdio requires a seek or eof between reads and writes on a
383 particular stream, so does Perl. (This doesn't apply to sysread()
386 While none of the built-in data types have any arbitrary size limits
387 (apart from memory size), there are still a few arbitrary limits: a
388 given variable name may not be longer than 251 characters. Line numbers
389 displayed by diagnostics are internally stored as short integers,
390 so they are limited to a maximum of 65535 (higher numbers usually being
391 affected by wraparound).
393 You may mail your bug reports (be sure to include full configuration
394 information as output by the myconfig program in the perl source
395 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
396 in compiling perl, the L<perlbug> script in the F<utils/> subdirectory
397 can be used to help mail in a bug report.
399 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
400 don't tell anyone I said that.
404 The Perl motto is "There's more than one way to do it." Divining
405 how many more is left as an exercise to the reader.
407 The three principal virtues of a programmer are Laziness,
408 Impatience, and Hubris. See the Camel Book for why.