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
137 perlrepository Perl source repository
141 perlbook Perl book information
142 perlcommunity Perl community information
143 perltodo Perl things to do
145 perldoc Look up Perl documentation in Pod format
147 perlhist Perl history records
148 perldelta Perl changes since previous version
149 perl5100delta Perl changes in version 5.10.0
150 perl595delta Perl changes in version 5.9.5
151 perl594delta Perl changes in version 5.9.4
152 perl593delta Perl changes in version 5.9.3
153 perl592delta Perl changes in version 5.9.2
154 perl591delta Perl changes in version 5.9.1
155 perl590delta Perl changes in version 5.9.0
156 perl588delta Perl changes in version 5.8.8
157 perl587delta Perl changes in version 5.8.7
158 perl586delta Perl changes in version 5.8.6
159 perl585delta Perl changes in version 5.8.5
160 perl584delta Perl changes in version 5.8.4
161 perl583delta Perl changes in version 5.8.3
162 perl582delta Perl changes in version 5.8.2
163 perl581delta Perl changes in version 5.8.1
164 perl58delta Perl changes in version 5.8.0
165 perl573delta Perl changes in version 5.7.3
166 perl572delta Perl changes in version 5.7.2
167 perl571delta Perl changes in version 5.7.1
168 perl570delta Perl changes in version 5.7.0
169 perl561delta Perl changes in version 5.6.1
170 perl56delta Perl changes in version 5.6
171 perl5005delta Perl changes in version 5.005
172 perl5004delta Perl changes in version 5.004
174 perlartistic Perl Artistic License
175 perlgpl GNU General Public License
177 =head2 Language-Specific
179 perlcn Perl for Simplified Chinese (in EUC-CN)
180 perljp Perl for Japanese (in EUC-JP)
181 perlko Perl for Korean (in EUC-KR)
182 perltw Perl for Traditional Chinese (in Big5)
184 =head2 Platform-Specific
186 perlaix Perl notes for AIX
187 perlamiga Perl notes for AmigaOS
188 perlapollo Perl notes for Apollo DomainOS
189 perlbeos Perl notes for BeOS
190 perlbs2000 Perl notes for POSIX-BC BS2000
191 perlce Perl notes for WinCE
192 perlcygwin Perl notes for Cygwin
193 perldgux Perl notes for DG/UX
194 perldos Perl notes for DOS
195 perlepoc Perl notes for EPOC
196 perlfreebsd Perl notes for FreeBSD
197 perlhaiku Perl notes for Haiku
198 perlhpux Perl notes for HP-UX
199 perlhurd Perl notes for Hurd
200 perlirix Perl notes for Irix
201 perllinux Perl notes for Linux
202 perlmachten Perl notes for Power MachTen
203 perlmacos Perl notes for Mac OS (Classic)
204 perlmacosx Perl notes for Mac OS X
205 perlmint Perl notes for MiNT
206 perlmpeix Perl notes for MPE/iX
207 perlnetware Perl notes for NetWare
208 perlopenbsd Perl notes for OpenBSD
209 perlos2 Perl notes for OS/2
210 perlos390 Perl notes for OS/390
211 perlos400 Perl notes for OS/400
212 perlplan9 Perl notes for Plan 9
213 perlqnx Perl notes for QNX
214 perlriscos Perl notes for RISC OS
215 perlsolaris Perl notes for Solaris
216 perlsymbian Perl notes for Symbian
217 perltru64 Perl notes for Tru64
218 perluts Perl notes for UTS
219 perlvmesa Perl notes for VM/ESA
220 perlvms Perl notes for VMS
221 perlvos Perl notes for Stratus VOS
222 perlwin32 Perl notes for Windows
225 By default, the manpages listed above are installed in the
226 F</usr/local/man/> directory.
228 Extensive additional documentation for Perl modules is available. The
229 default configuration for perl will place this additional documentation
230 in the F</usr/local/lib/perl5/man> directory (or else in the F<man>
231 subdirectory of the Perl library directory). Some of this additional
232 documentation is distributed standard with Perl, but you'll also find
233 documentation for third-party modules there.
235 You should be able to view Perl's documentation with your man(1)
236 program by including the proper directories in the appropriate start-up
237 files, or in the MANPATH environment variable. To find out where the
238 configuration has installed the manpages, type:
242 If the directories have a common stem, such as F</usr/local/man/man1>
243 and F</usr/local/man/man3>, you need only to add that stem
244 (F</usr/local/man>) to your man(1) configuration files or your MANPATH
245 environment variable. If they do not share a stem, you'll have to add
248 If that doesn't work for some reason, you can still use the
249 supplied F<perldoc> script to view module information. You might
250 also look into getting a replacement man program.
252 If something strange has gone wrong with your program and you're not
253 sure where you should look for help, try the B<-w> switch first. It
254 will often point out exactly where the trouble is.
258 Perl is a language optimized for scanning arbitrary
259 text files, extracting information from those text files, and printing
260 reports based on that information. It's also a good language for many
261 system management tasks. The language is intended to be practical
262 (easy to use, efficient, complete) rather than beautiful (tiny,
265 Perl combines (in the author's opinion, anyway) some of the best
266 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
267 those languages should have little difficulty with it. (Language
268 historians will also note some vestiges of B<csh>, Pascal, and even
269 BASIC-PLUS.) Expression syntax corresponds closely to C
270 expression syntax. Unlike most Unix utilities, Perl does not
271 arbitrarily limit the size of your data--if you've got the memory,
272 Perl can slurp in your whole file as a single string. Recursion is of
273 unlimited depth. And the tables used by hashes (sometimes called
274 "associative arrays") grow as necessary to prevent degraded
275 performance. Perl can use sophisticated pattern matching techniques to
276 scan large amounts of data quickly. Although optimized for
277 scanning text, Perl can also deal with binary data, and can make dbm
278 files look like hashes. Setuid Perl scripts are safer than C programs
279 through a dataflow tracing mechanism that prevents many stupid
282 If you have a problem that would ordinarily use B<sed> or B<awk> or
283 B<sh>, but it exceeds their capabilities or must run a little faster,
284 and you don't want to write the silly thing in C, then Perl may be for
285 you. There are also translators to turn your B<sed> and B<awk>
286 scripts into Perl scripts.
288 But wait, there's more...
290 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
291 rewrite that provides the following additional benefits:
297 modularity and reusability using innumerable modules
299 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
303 embeddable and extensible
305 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
306 L<perlguts>, and L<xsubpp>.
310 roll-your-own magic variables (including multiple simultaneous DBM
313 Described in L<perltie> and L<AnyDBM_File>.
317 subroutines can now be overridden, autoloaded, and prototyped
319 Described in L<perlsub>.
323 arbitrarily nested data structures and anonymous functions
325 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
329 object-oriented programming
331 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
336 support for light-weight processes (threads)
338 Described in L<perlthrtut> and L<threads>.
342 support for Unicode, internationalization, and localization
344 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
350 Described in L<perlsub>.
354 regular expression enhancements
356 Described in L<perlre>, with additional examples in L<perlop>.
360 enhanced debugger and interactive Perl environment,
361 with integrated editor support
363 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
367 POSIX 1003.1 compliant library
369 Described in L<POSIX>.
373 Okay, that's I<definitely> enough hype.
377 Perl is available for most operating systems, including virtually
378 all Unix-like platforms. See L<perlport/"Supported Platforms">
387 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
389 If your Perl success stories and testimonials may be of help to others
390 who wish to advocate the use of Perl in their applications,
391 or if you wish to simply express your gratitude to Larry and the
392 Perl developers, please write to perl-thanks@perl.org .
396 "@INC" locations of perl libraries
400 a2p awk to perl translator
401 s2p sed to perl translator
403 http://www.perl.org/ the Perl homepage
404 http://www.perl.com/ Perl articles (O'Reilly)
405 http://www.cpan.org/ the Comprehensive Perl Archive
406 http://www.pm.org/ the Perl Mongers
410 The C<use warnings> pragma (and the B<-w> switch) produces some
413 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
414 diagnostics> pragma automatically turns Perl's normally terse warnings
415 and errors into these longer forms.
417 Compilation errors will tell you the line number of the error, with an
418 indication of the next token or token type that was to be examined.
419 (In a script passed to Perl via B<-e> switches, each
420 B<-e> is counted as one line.)
422 Setuid scripts have additional constraints that can produce error
423 messages such as "Insecure dependency". See L<perlsec>.
425 Did we mention that you should definitely consider using the B<-w>
430 The B<-w> switch is not mandatory.
432 Perl is at the mercy of your machine's definitions of various
433 operations such as type casting, atof(), and floating-point
434 output with sprintf().
436 If your stdio requires a seek or eof between reads and writes on a
437 particular stream, so does Perl. (This doesn't apply to sysread()
440 While none of the built-in data types have any arbitrary size limits
441 (apart from memory size), there are still a few arbitrary limits: a
442 given variable name may not be longer than 251 characters. Line numbers
443 displayed by diagnostics are internally stored as short integers,
444 so they are limited to a maximum of 65535 (higher numbers usually being
445 affected by wraparound).
447 You may mail your bug reports (be sure to include full configuration
448 information as output by the myconfig program in the perl source
449 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
450 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
451 can be used to help mail in a bug report.
453 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
454 don't tell anyone I said that.
458 The Perl motto is "There's more than one way to do it." Divining
459 how many more is left as an exercise to the reader.
461 The three principal virtues of a programmer are Laziness,
462 Impatience, and Hubris. See the Camel Book for why.