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