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<https://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 h2ph h2xs perlbug pl2pm pod2html pod2man 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 perldeprecation Perl deprecations
102 perllexwarn Perl warnings and their control
103 perldebug Perl debugging
104 perlvar Perl predefined variables
105 perlre Perl regular expressions, the rest of the story
106 perlrebackslash Perl regular expression backslash sequences
107 perlrecharclass Perl regular expression character classes
108 perlreref Perl regular expressions quick reference
109 perlref Perl references, the rest of the story
110 perlform Perl formats
112 perltie Perl objects hidden behind simple variables
113 perldbmfilter Perl DBM filters
115 perlipc Perl interprocess communication
116 perlfork Perl fork() information
117 perlnumber Perl number semantics
119 perlthrtut Perl threads tutorial
121 perlport Perl portability guide
122 perllocale Perl locale support
123 perluniintro Perl Unicode introduction
124 perlunicode Perl Unicode support
125 perlunicook Perl Unicode cookbook
126 perlunifaq Perl Unicode FAQ
127 perluniprops Index of Unicode properties in Perl
128 perlunitut Perl Unicode tutorial
129 perlebcdic Considerations for running Perl on EBCDIC platforms
131 perlsec Perl security
133 perlmod Perl modules: how they work
134 perlmodlib Perl modules: how to write and use
135 perlmodstyle Perl modules: how to write modules with style
136 perlmodinstall Perl modules: how to install from CPAN
137 perlnewmod Perl modules: preparing a new module for distribution
138 perlpragma Perl modules: writing a user pragma
140 perlutil utilities packaged with the Perl distribution
142 perlfilter Perl source filters
144 perldtrace Perl's support for DTrace
146 perlglossary Perl Glossary
148 =head2 Internals and C Language Interface
150 perlembed Perl ways to embed perl in your C or C++ application
151 perldebguts Perl debugging guts and tips
152 perlxstut Perl XS tutorial
153 perlxs Perl XS application programming interface
154 perlxstypemap Perl XS C/Perl type conversion tools
155 perlclib Internal replacements for standard C library functions
156 perlguts Perl internal functions for those doing extensions
157 perlcall Perl calling conventions from C
158 perlmroapi Perl method resolution plugin interface
159 perlreapi Perl regular expression plugin interface
160 perlreguts Perl regular expression engine internals
162 perlapi Perl API listing (autogenerated)
163 perlintern Perl internal functions (autogenerated)
164 perliol C API for Perl's implementation of IO in Layers
165 perlapio Perl internal IO abstraction interface
167 perlhack Perl hackers guide
168 perlsource Guide to the Perl source tree
169 perlinterp Overview of the Perl interpreter source and how it works
170 perlhacktut Walk through the creation of a simple C code patch
171 perlhacktips Tips for Perl core C code hacking
172 perlpolicy Perl development policies
173 perlgit Using git with the Perl repository
177 perlbook Perl book information
178 perlcommunity Perl community information
180 perldoc Look up Perl documentation in Pod format
182 perlhist Perl history records
183 perldelta Perl changes since previous version
184 perl5330delta Perl changes in version 5.33.0
185 perl5320delta Perl changes in version 5.32.0
186 perl5303delta Perl changes in version 5.30.3
187 perl5302delta Perl changes in version 5.30.2
188 perl5301delta Perl changes in version 5.30.1
189 perl5300delta Perl changes in version 5.30.0
190 perl5283delta Perl changes in version 5.28.3
191 perl5282delta Perl changes in version 5.28.2
192 perl5281delta Perl changes in version 5.28.1
193 perl5280delta Perl changes in version 5.28.0
194 perl5263delta Perl changes in version 5.26.3
195 perl5262delta Perl changes in version 5.26.2
196 perl5261delta Perl changes in version 5.26.1
197 perl5260delta Perl changes in version 5.26.0
198 perl5244delta Perl changes in version 5.24.4
199 perl5243delta Perl changes in version 5.24.3
200 perl5242delta Perl changes in version 5.24.2
201 perl5241delta Perl changes in version 5.24.1
202 perl5240delta Perl changes in version 5.24.0
203 perl5224delta Perl changes in version 5.22.4
204 perl5223delta Perl changes in version 5.22.3
205 perl5222delta Perl changes in version 5.22.2
206 perl5221delta Perl changes in version 5.22.1
207 perl5220delta Perl changes in version 5.22.0
208 perl5203delta Perl changes in version 5.20.3
209 perl5202delta Perl changes in version 5.20.2
210 perl5201delta Perl changes in version 5.20.1
211 perl5200delta Perl changes in version 5.20.0
212 perl5184delta Perl changes in version 5.18.4
213 perl5182delta Perl changes in version 5.18.2
214 perl5181delta Perl changes in version 5.18.1
215 perl5180delta Perl changes in version 5.18.0
216 perl5163delta Perl changes in version 5.16.3
217 perl5162delta Perl changes in version 5.16.2
218 perl5161delta Perl changes in version 5.16.1
219 perl5160delta Perl changes in version 5.16.0
220 perl5144delta Perl changes in version 5.14.4
221 perl5143delta Perl changes in version 5.14.3
222 perl5142delta Perl changes in version 5.14.2
223 perl5141delta Perl changes in version 5.14.1
224 perl5140delta Perl changes in version 5.14.0
225 perl5125delta Perl changes in version 5.12.5
226 perl5124delta Perl changes in version 5.12.4
227 perl5123delta Perl changes in version 5.12.3
228 perl5122delta Perl changes in version 5.12.2
229 perl5121delta Perl changes in version 5.12.1
230 perl5120delta Perl changes in version 5.12.0
231 perl5101delta Perl changes in version 5.10.1
232 perl5100delta Perl changes in version 5.10.0
233 perl589delta Perl changes in version 5.8.9
234 perl588delta Perl changes in version 5.8.8
235 perl587delta Perl changes in version 5.8.7
236 perl586delta Perl changes in version 5.8.6
237 perl585delta Perl changes in version 5.8.5
238 perl584delta Perl changes in version 5.8.4
239 perl583delta Perl changes in version 5.8.3
240 perl582delta Perl changes in version 5.8.2
241 perl581delta Perl changes in version 5.8.1
242 perl58delta Perl changes in version 5.8.0
243 perl561delta Perl changes in version 5.6.1
244 perl56delta Perl changes in version 5.6
245 perl5005delta Perl changes in version 5.005
246 perl5004delta Perl changes in version 5.004
248 perlexperiment A listing of experimental features in Perl
250 perlartistic Perl Artistic License
251 perlgpl GNU General Public License
253 =head2 Language-Specific
255 =for buildtoc flag +r
257 perlcn Perl for Simplified Chinese (in UTF-8)
258 perljp Perl for Japanese (in EUC-JP)
259 perlko Perl for Korean (in EUC-KR)
260 perltw Perl for Traditional Chinese (in Big5)
262 =head2 Platform-Specific
264 perlaix Perl notes for AIX
265 perlamiga Perl notes for AmigaOS
266 perlandroid Perl notes for Android
267 perlbs2000 Perl notes for POSIX-BC BS2000
268 perlcygwin Perl notes for Cygwin
269 perldos Perl notes for DOS
270 perlfreebsd Perl notes for FreeBSD
271 perlhaiku Perl notes for Haiku
272 perlhpux Perl notes for HP-UX
273 perlhurd Perl notes for Hurd
274 perlirix Perl notes for Irix
275 perllinux Perl notes for Linux
276 perlmacos Perl notes for Mac OS (Classic)
277 perlmacosx Perl notes for Mac OS X
278 perlnetware Perl notes for NetWare
279 perlopenbsd Perl notes for OpenBSD
280 perlos2 Perl notes for OS/2
281 perlos390 Perl notes for OS/390
282 perlos400 Perl notes for OS/400
283 perlplan9 Perl notes for Plan 9
284 perlqnx Perl notes for QNX
285 perlriscos Perl notes for RISC OS
286 perlsolaris Perl notes for Solaris
287 perlsynology Perl notes for Synology
288 perltru64 Perl notes for Tru64
289 perlvms Perl notes for VMS
290 perlvos Perl notes for Stratus VOS
291 perlwin32 Perl notes for Windows
293 =for buildtoc flag -r
295 =head2 Stubs for Deleted Documents
304 =for buildtoc __END__
306 On a Unix-like system, these documentation files will usually also be
307 available as manpages for use with the F<man> program.
309 Some documentation is not available as man pages, so if a
310 cross-reference is not found by man, try it with L<perldoc>. Perldoc can
311 also take you directly to documentation for functions (with the B<-f>
312 switch). See C<perldoc --help> (or C<perldoc perldoc> or C<man perldoc>)
313 for other helpful options L<perldoc> has to offer.
315 In general, if something strange has gone wrong with your program and you're
316 not sure where you should look for help, try making your code comply with
317 B<use strict> and B<use warnings>. These will often point out exactly
318 where the trouble is.
322 Perl officially stands for Practical Extraction and Report Language,
323 except when it doesn't.
325 Perl was originally a language optimized for scanning arbitrary
326 text files, extracting information from those text files, and printing
327 reports based on that information. It quickly became a good language
328 for many system management tasks. Over the years, Perl has grown into
329 a general-purpose programming language. It's widely used for everything
330 from quick "one-liners" to full-scale application development.
332 The language is intended to be practical (easy to use, efficient,
333 complete) rather than beautiful (tiny, elegant, minimal). It combines
334 (in the author's opinion, anyway) some of the best features of B<sed>,
335 B<awk>, and B<sh>, making it familiar and easy to use for Unix users to
336 whip up quick solutions to annoying problems. Its general-purpose
337 programming facilities support procedural, functional, and
338 object-oriented programming paradigms, making Perl a comfortable
339 language for the long haul on major projects, whatever your bent.
341 Perl's roots in text processing haven't been forgotten over the years.
342 It still boasts some of the most powerful regular expressions to be
343 found anywhere, and its support for Unicode text is world-class. It
344 handles all kinds of structured text, too, through an extensive
345 collection of extensions. Those libraries, collected in the CPAN,
346 provide ready-made solutions to an astounding array of problems. When
347 they haven't set the standard themselves, they steal from the best
348 -- just like Perl itself.
352 Perl is available for most operating systems, including virtually
353 all Unix-like platforms. See L<perlport/"Supported Platforms">
358 See L<perlrun/ENVIRONMENT>.
362 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
364 If your Perl success stories and testimonials may be of help to others
365 who wish to advocate the use of Perl in their applications,
366 or if you wish to simply express your gratitude to Larry and the
367 Perl developers, please write to perl-thanks@perl.org .
371 "@INC" locations of perl libraries
373 "@INC" above is a reference to the built-in variable of the same name;
374 see L<perlvar> for more information.
378 https://www.perl.org/ the Perl homepage
379 https://www.perl.com/ Perl articles
380 https://www.cpan.org/ the Comprehensive Perl Archive
381 https://www.pm.org/ the Perl Mongers
385 Using the C<use strict> pragma ensures that all variables are properly
386 declared and prevents other misuses of legacy Perl features.
388 The C<use warnings> pragma produces some lovely diagnostics. One can
389 also use the B<-w> flag, but its use is normally discouraged, because
390 it gets applied to all executed Perl code, including that not under
393 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
394 diagnostics> pragma automatically turns Perl's normally terse warnings
395 and errors into these longer forms.
397 Compilation errors will tell you the line number of the error, with an
398 indication of the next token or token type that was to be examined.
399 (In a script passed to Perl via B<-e> switches, each
400 B<-e> is counted as one line.)
402 Setuid scripts have additional constraints that can produce error
403 messages such as "Insecure dependency". See L<perlsec>.
405 Did we mention that you should definitely consider using the B<use warnings>
410 The behavior implied by the B<use warnings> pragma is not mandatory.
412 Perl is at the mercy of your machine's definitions of various
413 operations such as type casting, atof(), and floating-point
414 output with sprintf().
416 If your stdio requires a seek or eof between reads and writes on a
417 particular stream, so does Perl. (This doesn't apply to sysread()
420 While none of the built-in data types have any arbitrary size limits
421 (apart from memory size), there are still a few arbitrary limits: a
422 given variable name may not be longer than 251 characters. Line numbers
423 displayed by diagnostics are internally stored as short integers,
424 so they are limited to a maximum of 65535 (higher numbers usually being
425 affected by wraparound).
427 You may submit your bug reports (be sure to include full configuration
428 information as output by the myconfig program in the perl source
429 tree, or by C<perl -V>) to L<https://github.com/Perl/perl5/issues>.
431 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
432 don't tell anyone I said that.
436 The Perl motto is "There's more than one way to do it." Divining
437 how many more is left as an exercise to the reader.
439 The three principal virtues of a programmer are Laziness,
440 Impatience, and Hubris. See the Camel Book for why.