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 perlebcdic Considerations for running Perl on EBCDIC platforms
100 perlsec Perl security
102 perlmod Perl modules: how they work
103 perlmodlib Perl modules: how to write and use
104 perlmodstyle Perl modules: how to write modules with style
105 perlmodinstall Perl modules: how to install from CPAN
106 perlnewmod Perl modules: preparing a new module for distribution
108 perlutil utilities packaged with the Perl distribution
110 perlcompile Perl compiler suite intro
112 perlfilter Perl source filters
114 perlglossary Perl Glossary
116 =head2 Internals and C Language Interface
118 perlembed Perl ways to embed perl in your C or C++ application
119 perldebguts Perl debugging guts and tips
120 perlxstut Perl XS tutorial
121 perlxs Perl XS application programming interface
122 perlclib Internal replacements for standard C library functions
123 perlguts Perl internal functions for those doing extensions
124 perlcall Perl calling conventions from C
126 perlapi Perl API listing (autogenerated)
127 perlintern Perl internal functions (autogenerated)
128 perliol C API for Perl's implementation of IO in Layers
129 perlapio Perl internal IO abstraction interface
131 perlhack Perl hackers guide
135 perlbook Perl book information
136 perltodo Perl things to do
138 perldoc Look up Perl documentation in Pod format
140 perlhist Perl history records
141 perldelta Perl changes since previous version
142 perl593delta Perl changes in version 5.9.3
143 perl592delta Perl changes in version 5.9.2
144 perl591delta Perl changes in version 5.9.1
145 perl590delta Perl changes in version 5.9.0
146 perl587delta Perl changes in version 5.8.7
147 perl586delta Perl changes in version 5.8.6
148 perl585delta Perl changes in version 5.8.5
149 perl584delta Perl changes in version 5.8.4
150 perl583delta Perl changes in version 5.8.3
151 perl582delta Perl changes in version 5.8.2
152 perl581delta Perl changes in version 5.8.1
153 perl58delta Perl changes in version 5.8.0
154 perl573delta Perl changes in version 5.7.3
155 perl572delta Perl changes in version 5.7.2
156 perl571delta Perl changes in version 5.7.1
157 perl570delta Perl changes in version 5.7.0
158 perl561delta Perl changes in version 5.6.1
159 perl56delta Perl changes in version 5.6
160 perl5005delta Perl changes in version 5.005
161 perl5004delta Perl changes in version 5.004
163 perlartistic Perl Artistic License
164 perlgpl GNU General Public License
166 =head2 Language-Specific
168 perlcn Perl for Simplified Chinese (in EUC-CN)
169 perljp Perl for Japanese (in EUC-JP)
170 perlko Perl for Korean (in EUC-KR)
171 perltw Perl for Traditional Chinese (in Big5)
173 =head2 Platform-Specific
175 perlaix Perl notes for AIX
176 perlamiga Perl notes for AmigaOS
177 perlapollo Perl notes for Apollo DomainOS
178 perlbeos Perl notes for BeOS
179 perlbs2000 Perl notes for POSIX-BC BS2000
180 perlce Perl notes for WinCE
181 perlcygwin Perl notes for Cygwin
182 perldgux Perl notes for DG/UX
183 perldos Perl notes for DOS
184 perlepoc Perl notes for EPOC
185 perlfreebsd Perl notes for FreeBSD
186 perlhpux Perl notes for HP-UX
187 perlhurd Perl notes for Hurd
188 perlirix Perl notes for Irix
189 perllinux Perl notes for Linux
190 perlmachten Perl notes for Power MachTen
191 perlmacos Perl notes for Mac OS (Classic)
192 perlmacosx Perl notes for Mac OS X
193 perlmint Perl notes for MiNT
194 perlmpeix Perl notes for MPE/iX
195 perlnetware Perl notes for NetWare
196 perlopenbsd Perl notes for OpenBSD
197 perlos2 Perl notes for OS/2
198 perlos390 Perl notes for OS/390
199 perlos400 Perl notes for OS/400
200 perlplan9 Perl notes for Plan 9
201 perlqnx Perl notes for QNX
202 perlsolaris Perl notes for Solaris
203 perlsymbian Perl notes for Symbian
204 perltru64 Perl notes for Tru64
205 perluts Perl notes for UTS
206 perlvmesa Perl notes for VM/ESA
207 perlvms Perl notes for VMS
208 perlvos Perl notes for Stratus VOS
209 perlwin32 Perl notes for Windows
212 By default, the manpages listed above are installed in the
213 F</usr/local/man/> directory.
215 Extensive additional documentation for Perl modules is available. The
216 default configuration for perl will place this additional documentation
217 in the F</usr/local/lib/perl5/man> directory (or else in the F<man>
218 subdirectory of the Perl library directory). Some of this additional
219 documentation is distributed standard with Perl, but you'll also find
220 documentation for third-party modules there.
222 You should be able to view Perl's documentation with your man(1)
223 program by including the proper directories in the appropriate start-up
224 files, or in the MANPATH environment variable. To find out where the
225 configuration has installed the manpages, type:
229 If the directories have a common stem, such as F</usr/local/man/man1>
230 and F</usr/local/man/man3>, you need only to add that stem
231 (F</usr/local/man>) to your man(1) configuration files or your MANPATH
232 environment variable. If they do not share a stem, you'll have to add
235 If that doesn't work for some reason, you can still use the
236 supplied F<perldoc> script to view module information. You might
237 also look into getting a replacement man program.
239 If something strange has gone wrong with your program and you're not
240 sure where you should look for help, try the B<-w> switch first. It
241 will often point out exactly where the trouble is.
245 Perl is a language optimized for scanning arbitrary
246 text files, extracting information from those text files, and printing
247 reports based on that information. It's also a good language for many
248 system management tasks. The language is intended to be practical
249 (easy to use, efficient, complete) rather than beautiful (tiny,
252 Perl combines (in the author's opinion, anyway) some of the best
253 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
254 those languages should have little difficulty with it. (Language
255 historians will also note some vestiges of B<csh>, Pascal, and even
256 BASIC-PLUS.) Expression syntax corresponds closely to C
257 expression syntax. Unlike most Unix utilities, Perl does not
258 arbitrarily limit the size of your data--if you've got the memory,
259 Perl can slurp in your whole file as a single string. Recursion is of
260 unlimited depth. And the tables used by hashes (sometimes called
261 "associative arrays") grow as necessary to prevent degraded
262 performance. Perl can use sophisticated pattern matching techniques to
263 scan large amounts of data quickly. Although optimized for
264 scanning text, Perl can also deal with binary data, and can make dbm
265 files look like hashes. Setuid Perl scripts are safer than C programs
266 through a dataflow tracing mechanism that prevents many stupid
269 If you have a problem that would ordinarily use B<sed> or B<awk> or
270 B<sh>, but it exceeds their capabilities or must run a little faster,
271 and you don't want to write the silly thing in C, then Perl may be for
272 you. There are also translators to turn your B<sed> and B<awk>
273 scripts into Perl scripts.
275 But wait, there's more...
277 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
278 rewrite that provides the following additional benefits:
284 modularity and reusability using innumerable modules
286 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
290 embeddable and extensible
292 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
293 L<perlguts>, and L<xsubpp>.
297 roll-your-own magic variables (including multiple simultaneous DBM
300 Described in L<perltie> and L<AnyDBM_File>.
304 subroutines can now be overridden, autoloaded, and prototyped
306 Described in L<perlsub>.
310 arbitrarily nested data structures and anonymous functions
312 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
316 object-oriented programming
318 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
323 support for light-weight processes (threads)
325 Described in L<perlthrtut> and L<threads>.
329 support for Unicode, internationalization, and localization
331 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
337 Described in L<perlsub>.
341 regular expression enhancements
343 Described in L<perlre>, with additional examples in L<perlop>.
347 enhanced debugger and interactive Perl environment,
348 with integrated editor support
350 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
354 POSIX 1003.1 compliant library
356 Described in L<POSIX>.
360 Okay, that's I<definitely> enough hype.
364 Perl is available for most operating systems, including virtually
365 all Unix-like platforms. See L<perlport/"Supported Platforms">
374 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
376 If your Perl success stories and testimonials may be of help to others
377 who wish to advocate the use of Perl in their applications,
378 or if you wish to simply express your gratitude to Larry and the
379 Perl developers, please write to perl-thanks@perl.org .
383 "@INC" locations of perl libraries
387 a2p awk to perl translator
388 s2p sed to perl translator
390 http://www.perl.org/ the Perl homepage
391 http://www.perl.com/ Perl articles (O'Reilly)
392 http://www.cpan.org/ the Comprehensive Perl Archive
393 http://www.pm.org/ the Perl Mongers
397 The C<use warnings> pragma (and the B<-w> switch) produces some
400 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
401 diagnostics> pragma automatically turns Perl's normally terse warnings
402 and errors into these longer forms.
404 Compilation errors will tell you the line number of the error, with an
405 indication of the next token or token type that was to be examined.
406 (In a script passed to Perl via B<-e> switches, each
407 B<-e> is counted as one line.)
409 Setuid scripts have additional constraints that can produce error
410 messages such as "Insecure dependency". See L<perlsec>.
412 Did we mention that you should definitely consider using the B<-w>
417 The B<-w> switch is not mandatory.
419 Perl is at the mercy of your machine's definitions of various
420 operations such as type casting, atof(), and floating-point
421 output with sprintf().
423 If your stdio requires a seek or eof between reads and writes on a
424 particular stream, so does Perl. (This doesn't apply to sysread()
427 While none of the built-in data types have any arbitrary size limits
428 (apart from memory size), there are still a few arbitrary limits: a
429 given variable name may not be longer than 251 characters. Line numbers
430 displayed by diagnostics are internally stored as short integers,
431 so they are limited to a maximum of 65535 (higher numbers usually being
432 affected by wraparound).
434 You may mail your bug reports (be sure to include full configuration
435 information as output by the myconfig program in the perl source
436 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
437 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
438 can be used to help mail in a bug report.
440 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
441 don't tell anyone I said that.
445 The Perl motto is "There's more than one way to do it." Divining
446 how many more is left as an exercise to the reader.
448 The three principal virtues of a programmer are Laziness,
449 Impatience, and Hubris. See the Camel Book for why.