3 perl - Practical Extraction and Report Language
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 If you're new to Perl, you should start with L<perlintro>, which is a
19 general intro for beginners and provides some background to help you
20 navigate the rest of Perl's extensive documentation.
22 For ease of access, the Perl manual has been split up into several sections.
26 perl Perl overview (this section)
27 perlintro Perl introduction for beginners
28 perltoc Perl documentation table of contents
32 perlreftut Perl references short introduction
33 perldsc Perl data structures intro
34 perllol Perl data structures: arrays of arrays
36 perlrequick Perl regular expressions quick start
37 perlretut Perl regular expressions tutorial
39 perlboot Perl OO tutorial for beginners
40 perltoot Perl OO tutorial, part 1
41 perltooc Perl OO tutorial, part 2
42 perlbot Perl OO tricks and examples
44 perlperf Perl Performance and Optimization Techniques
46 perlstyle Perl style guide
48 perlcheat Perl cheat sheet
49 perltrap Perl traps for the unwary
50 perldebtut Perl debugging tutorial
52 perlfaq Perl frequently asked questions
53 perlfaq1 General Questions About Perl
54 perlfaq2 Obtaining and Learning about Perl
55 perlfaq3 Programming Tools
56 perlfaq4 Data Manipulation
57 perlfaq5 Files and Formats
59 perlfaq7 Perl Language Issues
60 perlfaq8 System Interaction
63 =head2 Reference Manual
66 perldata Perl data structures
67 perlop Perl operators and precedence
68 perlsub Perl subroutines
69 perlfunc Perl built-in functions
70 perlopentut Perl open() tutorial
71 perlpacktut Perl pack() and unpack() tutorial
72 perlpod Perl plain old documentation
73 perlpodspec Perl plain old documentation format specification
74 perlrun Perl execution and options
75 perldiag Perl diagnostic messages
76 perllexwarn Perl warnings and their control
77 perldebug Perl debugging
78 perlvar Perl predefined variables
79 perlre Perl regular expressions, the rest of the story
80 perlrebackslash Perl regular expression backslash sequences
81 perlrecharclass Perl regular expression character classes
82 perlreref Perl regular expressions quick reference
83 perlref Perl references, the rest of the story
86 perltie Perl objects hidden behind simple variables
87 perldbmfilter Perl DBM filters
89 perlipc Perl interprocess communication
90 perlfork Perl fork() information
91 perlnumber Perl number semantics
93 perlthrtut Perl threads tutorial
95 perlport Perl portability guide
96 perllocale Perl locale support
97 perluniintro Perl Unicode introduction
98 perlunicode Perl Unicode support
99 perlunifaq Perl Unicode FAQ
100 perlunitut Perl Unicode tutorial
101 perlebcdic Considerations for running Perl on EBCDIC platforms
103 perlsec Perl security
105 perlmod Perl modules: how they work
106 perlmodlib Perl modules: how to write and use
107 perlmodstyle Perl modules: how to write modules with style
108 perlmodinstall Perl modules: how to install from CPAN
109 perlnewmod Perl modules: preparing a new module for distribution
110 perlpragma Perl modules: writing a user pragma
112 perlutil utilities packaged with the Perl distribution
114 perlcompile Perl compiler suite intro
116 perlfilter Perl source filters
118 perlglossary Perl Glossary
120 =head2 Internals and C Language Interface
122 perlembed Perl ways to embed perl in your C or C++ application
123 perldebguts Perl debugging guts and tips
124 perlxstut Perl XS tutorial
125 perlxs Perl XS application programming interface
126 perlclib Internal replacements for standard C library functions
127 perlguts Perl internal functions for those doing extensions
128 perlcall Perl calling conventions from C
129 perlmroapi Perl method resolution plugin interface
130 perlreapi Perl regular expression plugin interface
131 perlreguts Perl regular expression engine internals
133 perlapi Perl API listing (autogenerated)
134 perlintern Perl internal functions (autogenerated)
135 perliol C API for Perl's implementation of IO in Layers
136 perlapio Perl internal IO abstraction interface
138 perlhack Perl hackers guide
139 perlpolicy Perl development policies
140 perlrepository Perl source repository
144 perlbook Perl book information
145 perlcommunity Perl community information
146 perltodo Perl things to do
148 perldoc Look up Perl documentation in Pod format
150 perlhist Perl history records
151 perldelta Perl changes since previous version
152 perl5112delta Perl changes in version 5.11.2
153 perl5111delta Perl changes in version 5.11.1
154 perl5110delta Perl changes in version 5.11.0
155 perl5101delta Perl changes in version 5.10.1
156 perl5100delta Perl changes in version 5.10.0
157 perl595delta Perl changes in version 5.9.5
158 perl594delta Perl changes in version 5.9.4
159 perl593delta Perl changes in version 5.9.3
160 perl592delta Perl changes in version 5.9.2
161 perl591delta Perl changes in version 5.9.1
162 perl590delta Perl changes in version 5.9.0
163 perl589delta Perl changes in version 5.8.9
164 perl588delta Perl changes in version 5.8.8
165 perl587delta Perl changes in version 5.8.7
166 perl586delta Perl changes in version 5.8.6
167 perl585delta Perl changes in version 5.8.5
168 perl584delta Perl changes in version 5.8.4
169 perl583delta Perl changes in version 5.8.3
170 perl582delta Perl changes in version 5.8.2
171 perl581delta Perl changes in version 5.8.1
172 perl58delta Perl changes in version 5.8.0
173 perl573delta Perl changes in version 5.7.3
174 perl572delta Perl changes in version 5.7.2
175 perl571delta Perl changes in version 5.7.1
176 perl570delta Perl changes in version 5.7.0
177 perl561delta Perl changes in version 5.6.1
178 perl56delta Perl changes in version 5.6
179 perl5005delta Perl changes in version 5.005
180 perl5004delta Perl changes in version 5.004
182 perlartistic Perl Artistic License
183 perlgpl GNU General Public License
185 =head2 Language-Specific
187 perlcn Perl for Simplified Chinese (in EUC-CN)
188 perljp Perl for Japanese (in EUC-JP)
189 perlko Perl for Korean (in EUC-KR)
190 perltw Perl for Traditional Chinese (in Big5)
192 =head2 Platform-Specific
194 perlaix Perl notes for AIX
195 perlamiga Perl notes for AmigaOS
196 perlapollo Perl notes for Apollo DomainOS
197 perlbeos Perl notes for BeOS
198 perlbs2000 Perl notes for POSIX-BC BS2000
199 perlce Perl notes for WinCE
200 perlcygwin Perl notes for Cygwin
201 perldgux Perl notes for DG/UX
202 perldos Perl notes for DOS
203 perlepoc Perl notes for EPOC
204 perlfreebsd Perl notes for FreeBSD
205 perlhaiku Perl notes for Haiku
206 perlhpux Perl notes for HP-UX
207 perlhurd Perl notes for Hurd
208 perlirix Perl notes for Irix
209 perllinux Perl notes for Linux
210 perlmacos Perl notes for Mac OS (Classic)
211 perlmacosx Perl notes for Mac OS X
212 perlmpeix Perl notes for MPE/iX
213 perlnetware Perl notes for NetWare
214 perlopenbsd Perl notes for OpenBSD
215 perlos2 Perl notes for OS/2
216 perlos390 Perl notes for OS/390
217 perlos400 Perl notes for OS/400
218 perlplan9 Perl notes for Plan 9
219 perlqnx Perl notes for QNX
220 perlriscos Perl notes for RISC OS
221 perlsolaris Perl notes for Solaris
222 perlsymbian Perl notes for Symbian
223 perltru64 Perl notes for Tru64
224 perluts Perl notes for UTS
225 perlvmesa Perl notes for VM/ESA
226 perlvms Perl notes for VMS
227 perlvos Perl notes for Stratus VOS
228 perlwin32 Perl notes for Windows
231 By default, the manpages listed above are installed in the
232 F</usr/local/man/> directory.
234 Extensive additional documentation for Perl modules is available. The
235 default configuration for perl will place this additional documentation
236 in the F</usr/local/lib/perl5/man> directory (or else in the F<man>
237 subdirectory of the Perl library directory). Some of this additional
238 documentation is distributed standard with Perl, but you'll also find
239 documentation for third-party modules there.
241 You should be able to view Perl's documentation with your man(1)
242 program by including the proper directories in the appropriate start-up
243 files, or in the MANPATH environment variable. To find out where the
244 configuration has installed the manpages, type:
248 If the directories have a common stem, such as F</usr/local/man/man1>
249 and F</usr/local/man/man3>, you need only to add that stem
250 (F</usr/local/man>) to your man(1) configuration files or your MANPATH
251 environment variable. If they do not share a stem, you'll have to add
254 If that doesn't work for some reason, you can still use the
255 supplied F<perldoc> script to view module information. You might
256 also look into getting a replacement man program.
258 If something strange has gone wrong with your program and you're not
259 sure where you should look for help, try the B<-w> switch first. It
260 will often point out exactly where the trouble is.
264 Perl is a language optimized for scanning arbitrary
265 text files, extracting information from those text files, and printing
266 reports based on that information. It's also a good language for many
267 system management tasks. The language is intended to be practical
268 (easy to use, efficient, complete) rather than beautiful (tiny,
271 Perl combines (in the author's opinion, anyway) some of the best
272 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
273 those languages should have little difficulty with it. (Language
274 historians will also note some vestiges of B<csh>, Pascal, and even
275 BASIC-PLUS.) Expression syntax corresponds closely to C
276 expression syntax. Unlike most Unix utilities, Perl does not
277 arbitrarily limit the size of your data--if you've got the memory,
278 Perl can slurp in your whole file as a single string. Recursion is of
279 unlimited depth. And the tables used by hashes (sometimes called
280 "associative arrays") grow as necessary to prevent degraded
281 performance. Perl can use sophisticated pattern matching techniques to
282 scan large amounts of data quickly. Although optimized for
283 scanning text, Perl can also deal with binary data, and can make dbm
284 files look like hashes. Setuid Perl scripts are safer than C programs
285 through a dataflow tracing mechanism that prevents many stupid
288 If you have a problem that would ordinarily use B<sed> or B<awk> or
289 B<sh>, but it exceeds their capabilities or must run a little faster,
290 and you don't want to write the silly thing in C, then Perl may be for
291 you. There are also translators to turn your B<sed> and B<awk>
292 scripts into Perl scripts.
294 But wait, there's more...
296 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
297 rewrite that provides the following additional benefits:
303 modularity and reusability using innumerable modules
305 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
309 embeddable and extensible
311 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
312 L<perlguts>, and L<xsubpp>.
316 roll-your-own magic variables (including multiple simultaneous DBM
319 Described in L<perltie> and L<AnyDBM_File>.
323 subroutines can now be overridden, autoloaded, and prototyped
325 Described in L<perlsub>.
329 arbitrarily nested data structures and anonymous functions
331 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
335 object-oriented programming
337 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
342 support for light-weight processes (threads)
344 Described in L<perlthrtut> and L<threads>.
348 support for Unicode, internationalization, and localization
350 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
356 Described in L<perlsub>.
360 regular expression enhancements
362 Described in L<perlre>, with additional examples in L<perlop>.
366 enhanced debugger and interactive Perl environment,
367 with integrated editor support
369 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
373 POSIX 1003.1 compliant library
375 Described in L<POSIX>.
379 Okay, that's I<definitely> enough hype.
383 Perl is available for most operating systems, including virtually
384 all Unix-like platforms. See L<perlport/"Supported Platforms">
393 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
395 If your Perl success stories and testimonials may be of help to others
396 who wish to advocate the use of Perl in their applications,
397 or if you wish to simply express your gratitude to Larry and the
398 Perl developers, please write to perl-thanks@perl.org .
402 "@INC" locations of perl libraries
406 a2p awk to perl translator
407 s2p sed to perl translator
409 http://www.perl.org/ the Perl homepage
410 http://www.perl.com/ Perl articles (O'Reilly)
411 http://www.cpan.org/ the Comprehensive Perl Archive
412 http://www.pm.org/ the Perl Mongers
416 The C<use warnings> pragma (and the B<-w> switch) produces some
419 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
420 diagnostics> pragma automatically turns Perl's normally terse warnings
421 and errors into these longer forms.
423 Compilation errors will tell you the line number of the error, with an
424 indication of the next token or token type that was to be examined.
425 (In a script passed to Perl via B<-e> switches, each
426 B<-e> is counted as one line.)
428 Setuid scripts have additional constraints that can produce error
429 messages such as "Insecure dependency". See L<perlsec>.
431 Did we mention that you should definitely consider using the B<-w>
436 The B<-w> switch is not mandatory.
438 Perl is at the mercy of your machine's definitions of various
439 operations such as type casting, atof(), and floating-point
440 output with sprintf().
442 If your stdio requires a seek or eof between reads and writes on a
443 particular stream, so does Perl. (This doesn't apply to sysread()
446 While none of the built-in data types have any arbitrary size limits
447 (apart from memory size), there are still a few arbitrary limits: a
448 given variable name may not be longer than 251 characters. Line numbers
449 displayed by diagnostics are internally stored as short integers,
450 so they are limited to a maximum of 65535 (higher numbers usually being
451 affected by wraparound).
453 You may mail your bug reports (be sure to include full configuration
454 information as output by the myconfig program in the perl source
455 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
456 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
457 can be used to help mail in a bug report.
459 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
460 don't tell anyone I said that.
464 The Perl motto is "There's more than one way to do it." Divining
465 how many more is left as an exercise to the reader.
467 The three principal virtues of a programmer are Laziness,
468 Impatience, and Hubris. See the Camel Book for why.