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 perldocstyle Perl style guide for core docs
100 perlpodstyle Perl POD style guide
101 perldiag Perl diagnostic messages
102 perldeprecation Perl deprecations
103 perllexwarn Perl warnings and their control
104 perldebug Perl debugging
105 perlvar Perl predefined variables
106 perlre Perl regular expressions, the rest of the story
107 perlrebackslash Perl regular expression backslash sequences
108 perlrecharclass Perl regular expression character classes
109 perlreref Perl regular expressions quick reference
110 perlref Perl references, the rest of the story
111 perlform Perl formats
113 perltie Perl objects hidden behind simple variables
114 perldbmfilter Perl DBM filters
116 perlipc Perl interprocess communication
117 perlfork Perl fork() information
118 perlnumber Perl number semantics
120 perlthrtut Perl threads tutorial
122 perlport Perl portability guide
123 perllocale Perl locale support
124 perluniintro Perl Unicode introduction
125 perlunicode Perl Unicode support
126 perlunicook Perl Unicode cookbook
127 perlunifaq Perl Unicode FAQ
128 perluniprops Index of Unicode properties in Perl
129 perlunitut Perl Unicode tutorial
130 perlebcdic Considerations for running Perl on EBCDIC platforms
132 perlsec Perl security
133 perlsecpolicy Perl security report handling policy
135 perlmod Perl modules: how they work
136 perlmodlib Perl modules: how to write and use
137 perlmodstyle Perl modules: how to write modules with style
138 perlmodinstall Perl modules: how to install from CPAN
139 perlnewmod Perl modules: preparing a new module for distribution
140 perlpragma Perl modules: writing a user pragma
142 perlutil utilities packaged with the Perl distribution
144 perlfilter Perl source filters
146 perldtrace Perl's support for DTrace
148 perlglossary Perl Glossary
150 =head2 Internals and C Language Interface
152 perlembed Perl ways to embed perl in your C or C++ application
153 perldebguts Perl debugging guts and tips
154 perlxstut Perl XS tutorial
155 perlxs Perl XS application programming interface
156 perlxstypemap Perl XS C/Perl type conversion tools
157 perlclib Internal replacements for standard C library functions
158 perlguts Perl internal functions for those doing extensions
159 perlcall Perl calling conventions from C
160 perlmroapi Perl method resolution plugin interface
161 perlreapi Perl regular expression plugin interface
162 perlreguts Perl regular expression engine internals
164 perlapi Perl API listing (autogenerated)
165 perlintern Perl internal functions (autogenerated)
166 perliol C API for Perl's implementation of IO in Layers
167 perlapio Perl internal IO abstraction interface
169 perlhack Perl hackers guide
170 perlsource Guide to the Perl source tree
171 perlinterp Overview of the Perl interpreter source and how it works
172 perlhacktut Walk through the creation of a simple C code patch
173 perlhacktips Tips for Perl core C code hacking
174 perlpolicy Perl development policies
175 perlgov Perl Rules of Governance
176 perlgit Using git with the Perl repository
180 perlhist Perl history records
181 perldelta Perl changes since previous version
182 perl5358delta Perl changes in version 5.35.8
183 perl5357delta Perl changes in version 5.35.7
184 perl5356delta Perl changes in version 5.35.6
185 perl5355delta Perl changes in version 5.35.5
186 perl5354delta Perl changes in version 5.35.4
187 perl5353delta Perl changes in version 5.35.3
188 perl5352delta Perl changes in version 5.35.2
189 perl5351delta Perl changes in version 5.35.1
190 perl5350delta Perl changes in version 5.35.0
191 perl5340delta Perl changes in version 5.34.0
192 perl5321delta Perl changes in version 5.32.1
193 perl5320delta Perl changes in version 5.32.0
194 perl5303delta Perl changes in version 5.30.3
195 perl5302delta Perl changes in version 5.30.2
196 perl5301delta Perl changes in version 5.30.1
197 perl5300delta Perl changes in version 5.30.0
198 perl5283delta Perl changes in version 5.28.3
199 perl5282delta Perl changes in version 5.28.2
200 perl5281delta Perl changes in version 5.28.1
201 perl5280delta Perl changes in version 5.28.0
202 perl5263delta Perl changes in version 5.26.3
203 perl5262delta Perl changes in version 5.26.2
204 perl5261delta Perl changes in version 5.26.1
205 perl5260delta Perl changes in version 5.26.0
206 perl5244delta Perl changes in version 5.24.4
207 perl5243delta Perl changes in version 5.24.3
208 perl5242delta Perl changes in version 5.24.2
209 perl5241delta Perl changes in version 5.24.1
210 perl5240delta Perl changes in version 5.24.0
211 perl5224delta Perl changes in version 5.22.4
212 perl5223delta Perl changes in version 5.22.3
213 perl5222delta Perl changes in version 5.22.2
214 perl5221delta Perl changes in version 5.22.1
215 perl5220delta Perl changes in version 5.22.0
216 perl5203delta Perl changes in version 5.20.3
217 perl5202delta Perl changes in version 5.20.2
218 perl5201delta Perl changes in version 5.20.1
219 perl5200delta Perl changes in version 5.20.0
220 perl5184delta Perl changes in version 5.18.4
221 perl5182delta Perl changes in version 5.18.2
222 perl5181delta Perl changes in version 5.18.1
223 perl5180delta Perl changes in version 5.18.0
224 perl5163delta Perl changes in version 5.16.3
225 perl5162delta Perl changes in version 5.16.2
226 perl5161delta Perl changes in version 5.16.1
227 perl5160delta Perl changes in version 5.16.0
228 perl5144delta Perl changes in version 5.14.4
229 perl5143delta Perl changes in version 5.14.3
230 perl5142delta Perl changes in version 5.14.2
231 perl5141delta Perl changes in version 5.14.1
232 perl5140delta Perl changes in version 5.14.0
233 perl5125delta Perl changes in version 5.12.5
234 perl5124delta Perl changes in version 5.12.4
235 perl5123delta Perl changes in version 5.12.3
236 perl5122delta Perl changes in version 5.12.2
237 perl5121delta Perl changes in version 5.12.1
238 perl5120delta Perl changes in version 5.12.0
239 perl5101delta Perl changes in version 5.10.1
240 perl5100delta Perl changes in version 5.10.0
241 perl589delta Perl changes in version 5.8.9
242 perl588delta Perl changes in version 5.8.8
243 perl587delta Perl changes in version 5.8.7
244 perl586delta Perl changes in version 5.8.6
245 perl585delta Perl changes in version 5.8.5
246 perl584delta Perl changes in version 5.8.4
247 perl583delta Perl changes in version 5.8.3
248 perl582delta Perl changes in version 5.8.2
249 perl581delta Perl changes in version 5.8.1
250 perl58delta Perl changes in version 5.8.0
251 perl561delta Perl changes in version 5.6.1
252 perl56delta Perl changes in version 5.6
253 perl5005delta Perl changes in version 5.005
254 perl5004delta Perl changes in version 5.004
258 perlbook Perl book information
259 perlcommunity Perl community information
261 perldoc Look up Perl documentation in Pod format
263 perlexperiment A listing of experimental features in Perl
265 perlartistic Perl Artistic License
266 perlgpl GNU General Public License
268 =head2 Language-Specific
270 =for buildtoc flag +r
272 perlcn Perl for Simplified Chinese (in UTF-8)
273 perljp Perl for Japanese (in EUC-JP)
274 perlko Perl for Korean (in EUC-KR)
275 perltw Perl for Traditional Chinese (in Big5)
277 =head2 Platform-Specific
279 perlaix Perl notes for AIX
280 perlamiga Perl notes for AmigaOS
281 perlandroid Perl notes for Android
282 perlbs2000 Perl notes for POSIX-BC BS2000
283 perlcygwin Perl notes for Cygwin
284 perlfreebsd Perl notes for FreeBSD
285 perlhaiku Perl notes for Haiku
286 perlhpux Perl notes for HP-UX
287 perlhurd Perl notes for Hurd
288 perlirix Perl notes for Irix
289 perllinux Perl notes for Linux
290 perlmacos Perl notes for Mac OS (Classic)
291 perlmacosx Perl notes for Mac OS X
292 perlopenbsd Perl notes for OpenBSD
293 perlos2 Perl notes for OS/2
294 perlos390 Perl notes for OS/390
295 perlos400 Perl notes for OS/400
296 perlplan9 Perl notes for Plan 9
297 perlqnx Perl notes for QNX
298 perlriscos Perl notes for RISC OS
299 perlsolaris Perl notes for Solaris
300 perlsynology Perl notes for Synology
301 perltru64 Perl notes for Tru64
302 perlvms Perl notes for VMS
303 perlvos Perl notes for Stratus VOS
304 perlwin32 Perl notes for Windows
306 =for buildtoc flag -r
308 =head2 Stubs for Deleted Documents
317 =for buildtoc __END__
319 On a Unix-like system, these documentation files will usually also be
320 available as manpages for use with the F<man> program.
322 Some documentation is not available as man pages, so if a
323 cross-reference is not found by man, try it with L<perldoc>. Perldoc can
324 also take you directly to documentation for functions (with the B<-f>
325 switch). See C<perldoc --help> (or C<perldoc perldoc> or C<man perldoc>)
326 for other helpful options L<perldoc> has to offer.
328 In general, if something strange has gone wrong with your program and you're
329 not sure where you should look for help, try making your code comply with
330 B<use strict> and B<use warnings>. These will often point out exactly
331 where the trouble is.
335 Perl officially stands for Practical Extraction and Report Language,
336 except when it doesn't.
338 Perl was originally a language optimized for scanning arbitrary
339 text files, extracting information from those text files, and printing
340 reports based on that information. It quickly became a good language
341 for many system management tasks. Over the years, Perl has grown into
342 a general-purpose programming language. It's widely used for everything
343 from quick "one-liners" to full-scale application development.
345 The language is intended to be practical (easy to use, efficient,
346 complete) rather than beautiful (tiny, elegant, minimal). It combines
347 (in the author's opinion, anyway) some of the best features of B<sed>,
348 B<awk>, and B<sh>, making it familiar and easy to use for Unix users to
349 whip up quick solutions to annoying problems. Its general-purpose
350 programming facilities support procedural, functional, and
351 object-oriented programming paradigms, making Perl a comfortable
352 language for the long haul on major projects, whatever your bent.
354 Perl's roots in text processing haven't been forgotten over the years.
355 It still boasts some of the most powerful regular expressions to be
356 found anywhere, and its support for Unicode text is world-class. It
357 handles all kinds of structured text, too, through an extensive
358 collection of extensions. Those libraries, collected in the CPAN,
359 provide ready-made solutions to an astounding array of problems. When
360 they haven't set the standard themselves, they steal from the best
361 -- just like Perl itself.
365 Perl is available for most operating systems, including virtually
366 all Unix-like platforms. See L<perlport/"Supported Platforms">
371 See L<perlrun/ENVIRONMENT>.
375 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
377 If your Perl success stories and testimonials may be of help to others
378 who wish to advocate the use of Perl in their applications,
379 or if you wish to simply express your gratitude to Larry and the
380 Perl developers, please write to perl-thanks@perl.org .
384 "@INC" locations of perl libraries
386 "@INC" above is a reference to the built-in variable of the same name;
387 see L<perlvar> for more information.
391 https://www.perl.org/ the Perl homepage
392 https://www.perl.com/ Perl articles
393 https://www.cpan.org/ the Comprehensive Perl Archive
394 https://www.pm.org/ the Perl Mongers
398 Using the C<use strict> pragma ensures that all variables are properly
399 declared and prevents other misuses of legacy Perl features.
400 These are enabled by default within the scope of
401 C<L<use v5.12|perlfunc/use VERSION>> (or higher).
403 The C<use warnings> pragma produces some lovely diagnostics.
404 It is enabled by default when you say C<use v5.35> (or higher).
405 One can also use the B<-w> flag, but its use is normally discouraged,
406 because it gets applied to all executed Perl code, including that not under
409 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
410 diagnostics> pragma automatically turns Perl's normally terse warnings
411 and errors into these longer forms.
413 Compilation errors will tell you the line number of the error, with an
414 indication of the next token or token type that was to be examined.
415 (In a script passed to Perl via B<-e> switches, each
416 B<-e> is counted as one line.)
418 Setuid scripts have additional constraints that can produce error
419 messages such as "Insecure dependency". See L<perlsec>.
421 Did we mention that you should definitely consider using the B<use warnings>
426 The behavior implied by the B<use warnings> pragma is not mandatory.
428 Perl is at the mercy of your machine's definitions of various
429 operations such as type casting, atof(), and floating-point
430 output with sprintf().
432 If your stdio requires a seek or eof between reads and writes on a
433 particular stream, so does Perl. (This doesn't apply to sysread()
436 While none of the built-in data types have any arbitrary size limits
437 (apart from memory size), there are still a few arbitrary limits: a
438 given variable name may not be longer than 251 characters. Line numbers
439 displayed by diagnostics are internally stored as short integers,
440 so they are limited to a maximum of 65535 (higher numbers usually being
441 affected by wraparound).
443 You may submit your bug reports (be sure to include full configuration
444 information as output by the myconfig program in the perl source
445 tree, or by C<perl -V>) to L<https://github.com/Perl/perl5/issues>.
447 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
448 don't tell anyone I said that.
452 The Perl motto is "There's more than one way to do it." Divining
453 how many more is left as an exercise to the reader.
455 The three principal virtues of a programmer are Laziness,
456 Impatience, and Hubris. See the Camel Book for why.