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