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 perl5352delta Perl changes in version 5.35.2
183 perl5351delta Perl changes in version 5.35.1
184 perl5350delta Perl changes in version 5.35.0
185 perl5340delta Perl changes in version 5.34.0
186 perl5321delta Perl changes in version 5.32.1
187 perl5320delta Perl changes in version 5.32.0
188 perl5303delta Perl changes in version 5.30.3
189 perl5302delta Perl changes in version 5.30.2
190 perl5301delta Perl changes in version 5.30.1
191 perl5300delta Perl changes in version 5.30.0
192 perl5283delta Perl changes in version 5.28.3
193 perl5282delta Perl changes in version 5.28.2
194 perl5281delta Perl changes in version 5.28.1
195 perl5280delta Perl changes in version 5.28.0
196 perl5263delta Perl changes in version 5.26.3
197 perl5262delta Perl changes in version 5.26.2
198 perl5261delta Perl changes in version 5.26.1
199 perl5260delta Perl changes in version 5.26.0
200 perl5244delta Perl changes in version 5.24.4
201 perl5243delta Perl changes in version 5.24.3
202 perl5242delta Perl changes in version 5.24.2
203 perl5241delta Perl changes in version 5.24.1
204 perl5240delta Perl changes in version 5.24.0
205 perl5224delta Perl changes in version 5.22.4
206 perl5223delta Perl changes in version 5.22.3
207 perl5222delta Perl changes in version 5.22.2
208 perl5221delta Perl changes in version 5.22.1
209 perl5220delta Perl changes in version 5.22.0
210 perl5203delta Perl changes in version 5.20.3
211 perl5202delta Perl changes in version 5.20.2
212 perl5201delta Perl changes in version 5.20.1
213 perl5200delta Perl changes in version 5.20.0
214 perl5184delta Perl changes in version 5.18.4
215 perl5182delta Perl changes in version 5.18.2
216 perl5181delta Perl changes in version 5.18.1
217 perl5180delta Perl changes in version 5.18.0
218 perl5163delta Perl changes in version 5.16.3
219 perl5162delta Perl changes in version 5.16.2
220 perl5161delta Perl changes in version 5.16.1
221 perl5160delta Perl changes in version 5.16.0
222 perl5144delta Perl changes in version 5.14.4
223 perl5143delta Perl changes in version 5.14.3
224 perl5142delta Perl changes in version 5.14.2
225 perl5141delta Perl changes in version 5.14.1
226 perl5140delta Perl changes in version 5.14.0
227 perl5125delta Perl changes in version 5.12.5
228 perl5124delta Perl changes in version 5.12.4
229 perl5123delta Perl changes in version 5.12.3
230 perl5122delta Perl changes in version 5.12.2
231 perl5121delta Perl changes in version 5.12.1
232 perl5120delta Perl changes in version 5.12.0
233 perl5101delta Perl changes in version 5.10.1
234 perl5100delta Perl changes in version 5.10.0
235 perl589delta Perl changes in version 5.8.9
236 perl588delta Perl changes in version 5.8.8
237 perl587delta Perl changes in version 5.8.7
238 perl586delta Perl changes in version 5.8.6
239 perl585delta Perl changes in version 5.8.5
240 perl584delta Perl changes in version 5.8.4
241 perl583delta Perl changes in version 5.8.3
242 perl582delta Perl changes in version 5.8.2
243 perl581delta Perl changes in version 5.8.1
244 perl58delta Perl changes in version 5.8.0
245 perl561delta Perl changes in version 5.6.1
246 perl56delta Perl changes in version 5.6
247 perl5005delta Perl changes in version 5.005
248 perl5004delta Perl changes in version 5.004
252 perlbook Perl book information
253 perlcommunity Perl community information
255 perldoc Look up Perl documentation in Pod format
257 perlexperiment A listing of experimental features in Perl
259 perlartistic Perl Artistic License
260 perlgpl GNU General Public License
262 =head2 Language-Specific
264 =for buildtoc flag +r
266 perlcn Perl for Simplified Chinese (in UTF-8)
267 perljp Perl for Japanese (in EUC-JP)
268 perlko Perl for Korean (in EUC-KR)
269 perltw Perl for Traditional Chinese (in Big5)
271 =head2 Platform-Specific
273 perlaix Perl notes for AIX
274 perlamiga Perl notes for AmigaOS
275 perlandroid Perl notes for Android
276 perlbs2000 Perl notes for POSIX-BC BS2000
277 perlcygwin Perl notes for Cygwin
278 perldos Perl notes for DOS
279 perlfreebsd Perl notes for FreeBSD
280 perlhaiku Perl notes for Haiku
281 perlhpux Perl notes for HP-UX
282 perlhurd Perl notes for Hurd
283 perlirix Perl notes for Irix
284 perllinux Perl notes for Linux
285 perlmacos Perl notes for Mac OS (Classic)
286 perlmacosx Perl notes for Mac OS X
287 perlnetware Perl notes for NetWare
288 perlopenbsd Perl notes for OpenBSD
289 perlos2 Perl notes for OS/2
290 perlos390 Perl notes for OS/390
291 perlos400 Perl notes for OS/400
292 perlplan9 Perl notes for Plan 9
293 perlqnx Perl notes for QNX
294 perlriscos Perl notes for RISC OS
295 perlsolaris Perl notes for Solaris
296 perlsynology Perl notes for Synology
297 perltru64 Perl notes for Tru64
298 perlvms Perl notes for VMS
299 perlvos Perl notes for Stratus VOS
300 perlwin32 Perl notes for Windows
302 =for buildtoc flag -r
304 =head2 Stubs for Deleted Documents
313 =for buildtoc __END__
315 On a Unix-like system, these documentation files will usually also be
316 available as manpages for use with the F<man> program.
318 Some documentation is not available as man pages, so if a
319 cross-reference is not found by man, try it with L<perldoc>. Perldoc can
320 also take you directly to documentation for functions (with the B<-f>
321 switch). See C<perldoc --help> (or C<perldoc perldoc> or C<man perldoc>)
322 for other helpful options L<perldoc> has to offer.
324 In general, if something strange has gone wrong with your program and you're
325 not sure where you should look for help, try making your code comply with
326 B<use strict> and B<use warnings>. These will often point out exactly
327 where the trouble is.
331 Perl officially stands for Practical Extraction and Report Language,
332 except when it doesn't.
334 Perl was originally a language optimized for scanning arbitrary
335 text files, extracting information from those text files, and printing
336 reports based on that information. It quickly became a good language
337 for many system management tasks. Over the years, Perl has grown into
338 a general-purpose programming language. It's widely used for everything
339 from quick "one-liners" to full-scale application development.
341 The language is intended to be practical (easy to use, efficient,
342 complete) rather than beautiful (tiny, elegant, minimal). It combines
343 (in the author's opinion, anyway) some of the best features of B<sed>,
344 B<awk>, and B<sh>, making it familiar and easy to use for Unix users to
345 whip up quick solutions to annoying problems. Its general-purpose
346 programming facilities support procedural, functional, and
347 object-oriented programming paradigms, making Perl a comfortable
348 language for the long haul on major projects, whatever your bent.
350 Perl's roots in text processing haven't been forgotten over the years.
351 It still boasts some of the most powerful regular expressions to be
352 found anywhere, and its support for Unicode text is world-class. It
353 handles all kinds of structured text, too, through an extensive
354 collection of extensions. Those libraries, collected in the CPAN,
355 provide ready-made solutions to an astounding array of problems. When
356 they haven't set the standard themselves, they steal from the best
357 -- just like Perl itself.
361 Perl is available for most operating systems, including virtually
362 all Unix-like platforms. See L<perlport/"Supported Platforms">
367 See L<perlrun/ENVIRONMENT>.
371 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
373 If your Perl success stories and testimonials may be of help to others
374 who wish to advocate the use of Perl in their applications,
375 or if you wish to simply express your gratitude to Larry and the
376 Perl developers, please write to perl-thanks@perl.org .
380 "@INC" locations of perl libraries
382 "@INC" above is a reference to the built-in variable of the same name;
383 see L<perlvar> for more information.
387 https://www.perl.org/ the Perl homepage
388 https://www.perl.com/ Perl articles
389 https://www.cpan.org/ the Comprehensive Perl Archive
390 https://www.pm.org/ the Perl Mongers
394 Using the C<use strict> pragma ensures that all variables are properly
395 declared and prevents other misuses of legacy Perl features.
397 The C<use warnings> pragma produces some lovely diagnostics. One can
398 also use the B<-w> flag, but its use is normally discouraged, because
399 it gets applied to all executed Perl code, including that not under
402 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
403 diagnostics> pragma automatically turns Perl's normally terse warnings
404 and errors into these longer forms.
406 Compilation errors will tell you the line number of the error, with an
407 indication of the next token or token type that was to be examined.
408 (In a script passed to Perl via B<-e> switches, each
409 B<-e> is counted as one line.)
411 Setuid scripts have additional constraints that can produce error
412 messages such as "Insecure dependency". See L<perlsec>.
414 Did we mention that you should definitely consider using the B<use warnings>
419 The behavior implied by the B<use warnings> pragma is not mandatory.
421 Perl is at the mercy of your machine's definitions of various
422 operations such as type casting, atof(), and floating-point
423 output with sprintf().
425 If your stdio requires a seek or eof between reads and writes on a
426 particular stream, so does Perl. (This doesn't apply to sysread()
429 While none of the built-in data types have any arbitrary size limits
430 (apart from memory size), there are still a few arbitrary limits: a
431 given variable name may not be longer than 251 characters. Line numbers
432 displayed by diagnostics are internally stored as short integers,
433 so they are limited to a maximum of 65535 (higher numbers usually being
434 affected by wraparound).
436 You may submit your bug reports (be sure to include full configuration
437 information as output by the myconfig program in the perl source
438 tree, or by C<perl -V>) to L<https://github.com/Perl/perl5/issues>.
440 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
441 don't tell anyone I said that.
445 The Perl motto is "There's more than one way to do it." Divining
446 how many more is left as an exercise to the reader.
448 The three principal virtues of a programmer are Laziness,
449 Impatience, and Hubris. See the Camel Book for why.