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 c2ph 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 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 perlunicook Perl Unicode cookbook
125 perlunifaq Perl Unicode FAQ
126 perluniprops Index of Unicode properties in Perl
127 perlunitut Perl Unicode tutorial
128 perlebcdic Considerations for running Perl on EBCDIC platforms
130 perlsec Perl security
132 perlmod Perl modules: how they work
133 perlmodlib Perl modules: how to write and use
134 perlmodstyle Perl modules: how to write modules with style
135 perlmodinstall Perl modules: how to install from CPAN
136 perlnewmod Perl modules: preparing a new module for distribution
137 perlpragma Perl modules: writing a user pragma
139 perlutil utilities packaged with the Perl distribution
141 perlfilter Perl source filters
143 perldtrace Perl's support for DTrace
145 perlglossary Perl Glossary
147 =head2 Internals and C Language Interface
149 perlembed Perl ways to embed perl in your C or C++ application
150 perldebguts Perl debugging guts and tips
151 perlxstut Perl XS tutorial
152 perlxs Perl XS application programming interface
153 perlxstypemap Perl XS C/Perl type conversion tools
154 perlclib Internal replacements for standard C library functions
155 perlguts Perl internal functions for those doing extensions
156 perlcall Perl calling conventions from C
157 perlmroapi Perl method resolution plugin interface
158 perlreapi Perl regular expression plugin interface
159 perlreguts Perl regular expression engine internals
161 perlapi Perl API listing (autogenerated)
162 perlintern Perl internal functions (autogenerated)
163 perliol C API for Perl's implementation of IO in Layers
164 perlapio Perl internal IO abstraction interface
166 perlhack Perl hackers guide
167 perlsource Guide to the Perl source tree
168 perlinterp Overview of the Perl interpreter source and how it works
169 perlhacktut Walk through the creation of a simple C code patch
170 perlhacktips Tips for Perl core C code hacking
171 perlpolicy Perl development policies
172 perlgit Using git with the Perl repository
176 perlbook Perl book information
177 perlcommunity Perl community information
179 perldoc Look up Perl documentation in Pod format
181 perlhist Perl history records
182 perldelta Perl changes since previous version
183 perl5258delta Perl changes in version 5.25.8
184 perl5257delta Perl changes in version 5.25.7
185 perl5256delta Perl changes in version 5.25.6
186 perl5255delta Perl changes in version 5.25.5
187 perl5254delta Perl changes in version 5.25.4
188 perl5253delta Perl changes in version 5.25.3
189 perl5252delta Perl changes in version 5.25.2
190 perl5251delta Perl changes in version 5.25.1
191 perl5250delta Perl changes in version 5.25.0
192 perl5240delta Perl changes in version 5.24.0
193 perl5222delta Perl changes in version 5.22.2
194 perl5221delta Perl changes in version 5.22.1
195 perl5220delta Perl changes in version 5.22.0
196 perl5203delta Perl changes in version 5.20.3
197 perl5202delta Perl changes in version 5.20.2
198 perl5201delta Perl changes in version 5.20.1
199 perl5200delta Perl changes in version 5.20.0
200 perl5184delta Perl changes in version 5.18.4
201 perl5182delta Perl changes in version 5.18.2
202 perl5181delta Perl changes in version 5.18.1
203 perl5180delta Perl changes in version 5.18.0
204 perl5163delta Perl changes in version 5.16.3
205 perl5162delta Perl changes in version 5.16.2
206 perl5161delta Perl changes in version 5.16.1
207 perl5160delta Perl changes in version 5.16.0
208 perl5144delta Perl changes in version 5.14.4
209 perl5143delta Perl changes in version 5.14.3
210 perl5142delta Perl changes in version 5.14.2
211 perl5141delta Perl changes in version 5.14.1
212 perl5140delta Perl changes in version 5.14.0
213 perl5125delta Perl changes in version 5.12.5
214 perl5124delta Perl changes in version 5.12.4
215 perl5123delta Perl changes in version 5.12.3
216 perl5122delta Perl changes in version 5.12.2
217 perl5121delta Perl changes in version 5.12.1
218 perl5120delta Perl changes in version 5.12.0
219 perl5101delta Perl changes in version 5.10.1
220 perl5100delta Perl changes in version 5.10.0
221 perl589delta Perl changes in version 5.8.9
222 perl588delta Perl changes in version 5.8.8
223 perl587delta Perl changes in version 5.8.7
224 perl586delta Perl changes in version 5.8.6
225 perl585delta Perl changes in version 5.8.5
226 perl584delta Perl changes in version 5.8.4
227 perl583delta Perl changes in version 5.8.3
228 perl582delta Perl changes in version 5.8.2
229 perl581delta Perl changes in version 5.8.1
230 perl58delta Perl changes in version 5.8.0
231 perl561delta Perl changes in version 5.6.1
232 perl56delta Perl changes in version 5.6
233 perl5005delta Perl changes in version 5.005
234 perl5004delta Perl changes in version 5.004
236 perlexperiment A listing of experimental features in Perl
238 perlartistic Perl Artistic License
239 perlgpl GNU General Public License
241 =head2 Language-Specific
243 =for buildtoc flag +r
245 perlcn Perl for Simplified Chinese (in EUC-CN)
246 perljp Perl for Japanese (in EUC-JP)
247 perlko Perl for Korean (in EUC-KR)
248 perltw Perl for Traditional Chinese (in Big5)
250 =head2 Platform-Specific
252 perlaix Perl notes for AIX
253 perlamiga Perl notes for AmigaOS
254 perlandroid Perl notes for Android
255 perlbs2000 Perl notes for POSIX-BC BS2000
256 perlce Perl notes for WinCE
257 perlcygwin Perl notes for Cygwin
258 perldos Perl notes for DOS
259 perlfreebsd Perl notes for FreeBSD
260 perlhaiku Perl notes for Haiku
261 perlhpux Perl notes for HP-UX
262 perlhurd Perl notes for Hurd
263 perlirix Perl notes for Irix
264 perllinux Perl notes for Linux
265 perlmacos Perl notes for Mac OS (Classic)
266 perlmacosx Perl notes for Mac OS X
267 perlnetware Perl notes for NetWare
268 perlopenbsd Perl notes for OpenBSD
269 perlos2 Perl notes for OS/2
270 perlos390 Perl notes for OS/390
271 perlos400 Perl notes for OS/400
272 perlplan9 Perl notes for Plan 9
273 perlqnx Perl notes for QNX
274 perlriscos Perl notes for RISC OS
275 perlsolaris Perl notes for Solaris
276 perlsymbian Perl notes for Symbian
277 perlsynology Perl notes for Synology
278 perltru64 Perl notes for Tru64
279 perlvms Perl notes for VMS
280 perlvos Perl notes for Stratus VOS
281 perlwin32 Perl notes for Windows
283 =for buildtoc flag -r
285 =head2 Stubs for Deleted Documents
294 =for buildtoc __END__
296 On a Unix-like system, these documentation files will usually also be
297 available as manpages for use with the F<man> program.
299 Some documentation is not available as man pages, so if a
300 cross-reference is not found by man, try it with L<perldoc>. Perldoc can
301 also take you directly to documentation for functions (with the B<-f>
302 switch). See C<perldoc --help> (or C<perldoc perldoc> or C<man perldoc>)
303 for other helpful options L<perldoc> has to offer.
305 In general, if something strange has gone wrong with your program and you're
306 not sure where you should look for help, try making your code comply with
307 B<use strict> and B<use warnings>. These will often point out exactly
308 where the trouble is.
312 Perl officially stands for Practical Extraction and Report Language,
313 except when it doesn't.
315 Perl was originally a language optimized for scanning arbitrary
316 text files, extracting information from those text files, and printing
317 reports based on that information. It quickly became a good language
318 for many system management tasks. Over the years, Perl has grown into
319 a general-purpose programming language. It's widely used for everything
320 from quick "one-liners" to full-scale application development.
322 The language is intended to be practical (easy to use, efficient,
323 complete) rather than beautiful (tiny, elegant, minimal). It combines
324 (in the author's opinion, anyway) some of the best features of B<sed>,
325 B<awk>, and B<sh>, making it familiar and easy to use for Unix users to
326 whip up quick solutions to annoying problems. Its general-purpose
327 programming facilities support procedural, functional, and
328 object-oriented programming paradigms, making Perl a comfortable
329 language for the long haul on major projects, whatever your bent.
331 Perl's roots in text processing haven't been forgotten over the years.
332 It still boasts some of the most powerful regular expressions to be
333 found anywhere, and its support for Unicode text is world-class. It
334 handles all kinds of structured text, too, through an extensive
335 collection of extensions. Those libraries, collected in the CPAN,
336 provide ready-made solutions to an astounding array of problems. When
337 they haven't set the standard themselves, they steal from the best
338 -- just like Perl itself.
342 Perl is available for most operating systems, including virtually
343 all Unix-like platforms. See L<perlport/"Supported Platforms">
352 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
354 If your Perl success stories and testimonials may be of help to others
355 who wish to advocate the use of Perl in their applications,
356 or if you wish to simply express your gratitude to Larry and the
357 Perl developers, please write to perl-thanks@perl.org .
361 "@INC" locations of perl libraries
363 "@INC" above is a reference to the built-in variable of the same name;
364 see L<perlvar> for more information.
368 http://www.perl.org/ the Perl homepage
369 http://www.perl.com/ Perl articles (O'Reilly)
370 http://www.cpan.org/ the Comprehensive Perl Archive
371 http://www.pm.org/ the Perl Mongers
375 Using the C<use strict> pragma ensures that all variables are properly
376 declared and prevents other misuses of legacy Perl features.
378 The C<use warnings> pragma produces some lovely diagnostics. One can
379 also use the B<-w> flag, but its use is normally discouraged, because
380 it gets applied to all executed Perl code, including that not under
383 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
384 diagnostics> pragma automatically turns Perl's normally terse warnings
385 and errors into these longer forms.
387 Compilation errors will tell you the line number of the error, with an
388 indication of the next token or token type that was to be examined.
389 (In a script passed to Perl via B<-e> switches, each
390 B<-e> is counted as one line.)
392 Setuid scripts have additional constraints that can produce error
393 messages such as "Insecure dependency". See L<perlsec>.
395 Did we mention that you should definitely consider using the B<use warnings>
400 The behavior implied by the B<use warnings> pragma is not mandatory.
402 Perl is at the mercy of your machine's definitions of various
403 operations such as type casting, atof(), and floating-point
404 output with sprintf().
406 If your stdio requires a seek or eof between reads and writes on a
407 particular stream, so does Perl. (This doesn't apply to sysread()
410 While none of the built-in data types have any arbitrary size limits
411 (apart from memory size), there are still a few arbitrary limits: a
412 given variable name may not be longer than 251 characters. Line numbers
413 displayed by diagnostics are internally stored as short integers,
414 so they are limited to a maximum of 65535 (higher numbers usually being
415 affected by wraparound).
417 You may mail your bug reports (be sure to include full configuration
418 information as output by the myconfig program in the perl source
419 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
420 in compiling perl, the L<perlbug> script in the F<utils/> subdirectory
421 can be used to help mail in a bug report.
423 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
424 don't tell anyone I said that.
428 The Perl motto is "There's more than one way to do it." Divining
429 how many more is left as an exercise to the reader.
431 The three principal virtues of a programmer are Laziness,
432 Impatience, and Hubris. See the Camel Book for why.