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 perlunitut Perl Unicode tutorial
99 perlebcdic Considerations for running Perl on EBCDIC platforms
101 perlsec Perl security
103 perlmod Perl modules: how they work
104 perlmodlib Perl modules: how to write and use
105 perlmodstyle Perl modules: how to write modules with style
106 perlmodinstall Perl modules: how to install from CPAN
107 perlnewmod Perl modules: preparing a new module for distribution
108 perlpragma Perl modules: writing a user pragma
110 perlutil utilities packaged with the Perl distribution
112 perlcompile Perl compiler suite intro
114 perlfilter Perl source filters
116 perlglossary Perl Glossary
118 =head2 Internals and C Language Interface
120 perlembed Perl ways to embed perl in your C or C++ application
121 perldebguts Perl debugging guts and tips
122 perlxstut Perl XS tutorial
123 perlxs Perl XS application programming interface
124 perlclib Internal replacements for standard C library functions
125 perlguts Perl internal functions for those doing extensions
126 perlcall Perl calling conventions from C
127 perlreguts Perl regular expression engine internals
129 perlapi Perl API listing (autogenerated)
130 perlintern Perl internal functions (autogenerated)
131 perliol C API for Perl's implementation of IO in Layers
132 perlapio Perl internal IO abstraction interface
134 perlhack Perl hackers guide
138 perlbook Perl book information
139 perltodo Perl things to do
141 perldoc Look up Perl documentation in Pod format
143 perlhist Perl history records
144 perldelta Perl changes since previous version
145 perl594delta Perl changes in version 5.9.4
146 perl593delta Perl changes in version 5.9.3
147 perl592delta Perl changes in version 5.9.2
148 perl591delta Perl changes in version 5.9.1
149 perl590delta Perl changes in version 5.9.0
150 perl588delta Perl changes in version 5.8.8
151 perl587delta Perl changes in version 5.8.7
152 perl586delta Perl changes in version 5.8.6
153 perl585delta Perl changes in version 5.8.5
154 perl584delta Perl changes in version 5.8.4
155 perl583delta Perl changes in version 5.8.3
156 perl582delta Perl changes in version 5.8.2
157 perl581delta Perl changes in version 5.8.1
158 perl58delta Perl changes in version 5.8.0
159 perl573delta Perl changes in version 5.7.3
160 perl572delta Perl changes in version 5.7.2
161 perl571delta Perl changes in version 5.7.1
162 perl570delta Perl changes in version 5.7.0
163 perl561delta Perl changes in version 5.6.1
164 perl56delta Perl changes in version 5.6
165 perl5005delta Perl changes in version 5.005
166 perl5004delta Perl changes in version 5.004
168 perlartistic Perl Artistic License
169 perlgpl GNU General Public License
171 =head2 Language-Specific
173 perlcn Perl for Simplified Chinese (in EUC-CN)
174 perljp Perl for Japanese (in EUC-JP)
175 perlko Perl for Korean (in EUC-KR)
176 perltw Perl for Traditional Chinese (in Big5)
178 =head2 Platform-Specific
180 perlaix Perl notes for AIX
181 perlamiga Perl notes for AmigaOS
182 perlapollo Perl notes for Apollo DomainOS
183 perlbeos Perl notes for BeOS
184 perlbs2000 Perl notes for POSIX-BC BS2000
185 perlce Perl notes for WinCE
186 perlcygwin Perl notes for Cygwin
187 perldgux Perl notes for DG/UX
188 perldos Perl notes for DOS
189 perlepoc Perl notes for EPOC
190 perlfreebsd Perl notes for FreeBSD
191 perlhpux Perl notes for HP-UX
192 perlhurd Perl notes for Hurd
193 perlirix Perl notes for Irix
194 perllinux Perl notes for Linux
195 perlmachten Perl notes for Power MachTen
196 perlmacos Perl notes for Mac OS (Classic)
197 perlmacosx Perl notes for Mac OS X
198 perlmint Perl notes for MiNT
199 perlmpeix Perl notes for MPE/iX
200 perlnetware Perl notes for NetWare
201 perlopenbsd Perl notes for OpenBSD
202 perlos2 Perl notes for OS/2
203 perlos390 Perl notes for OS/390
204 perlos400 Perl notes for OS/400
205 perlplan9 Perl notes for Plan 9
206 perlqnx Perl notes for QNX
207 perlriscos Perl notes for RISC OS
208 perlsolaris Perl notes for Solaris
209 perlsymbian Perl notes for Symbian
210 perltru64 Perl notes for Tru64
211 perluts Perl notes for UTS
212 perlvmesa Perl notes for VM/ESA
213 perlvms Perl notes for VMS
214 perlvos Perl notes for Stratus VOS
215 perlwin32 Perl notes for Windows
218 By default, the manpages listed above are installed in the
219 F</usr/local/man/> directory.
221 Extensive additional documentation for Perl modules is available. The
222 default configuration for perl will place this additional documentation
223 in the F</usr/local/lib/perl5/man> directory (or else in the F<man>
224 subdirectory of the Perl library directory). Some of this additional
225 documentation is distributed standard with Perl, but you'll also find
226 documentation for third-party modules there.
228 You should be able to view Perl's documentation with your man(1)
229 program by including the proper directories in the appropriate start-up
230 files, or in the MANPATH environment variable. To find out where the
231 configuration has installed the manpages, type:
235 If the directories have a common stem, such as F</usr/local/man/man1>
236 and F</usr/local/man/man3>, you need only to add that stem
237 (F</usr/local/man>) to your man(1) configuration files or your MANPATH
238 environment variable. If they do not share a stem, you'll have to add
241 If that doesn't work for some reason, you can still use the
242 supplied F<perldoc> script to view module information. You might
243 also look into getting a replacement man program.
245 If something strange has gone wrong with your program and you're not
246 sure where you should look for help, try the B<-w> switch first. It
247 will often point out exactly where the trouble is.
251 Perl is a language optimized for scanning arbitrary
252 text files, extracting information from those text files, and printing
253 reports based on that information. It's also a good language for many
254 system management tasks. The language is intended to be practical
255 (easy to use, efficient, complete) rather than beautiful (tiny,
258 Perl combines (in the author's opinion, anyway) some of the best
259 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
260 those languages should have little difficulty with it. (Language
261 historians will also note some vestiges of B<csh>, Pascal, and even
262 BASIC-PLUS.) Expression syntax corresponds closely to C
263 expression syntax. Unlike most Unix utilities, Perl does not
264 arbitrarily limit the size of your data--if you've got the memory,
265 Perl can slurp in your whole file as a single string. Recursion is of
266 unlimited depth. And the tables used by hashes (sometimes called
267 "associative arrays") grow as necessary to prevent degraded
268 performance. Perl can use sophisticated pattern matching techniques to
269 scan large amounts of data quickly. Although optimized for
270 scanning text, Perl can also deal with binary data, and can make dbm
271 files look like hashes. Setuid Perl scripts are safer than C programs
272 through a dataflow tracing mechanism that prevents many stupid
275 If you have a problem that would ordinarily use B<sed> or B<awk> or
276 B<sh>, but it exceeds their capabilities or must run a little faster,
277 and you don't want to write the silly thing in C, then Perl may be for
278 you. There are also translators to turn your B<sed> and B<awk>
279 scripts into Perl scripts.
281 But wait, there's more...
283 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
284 rewrite that provides the following additional benefits:
290 modularity and reusability using innumerable modules
292 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
296 embeddable and extensible
298 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
299 L<perlguts>, and L<xsubpp>.
303 roll-your-own magic variables (including multiple simultaneous DBM
306 Described in L<perltie> and L<AnyDBM_File>.
310 subroutines can now be overridden, autoloaded, and prototyped
312 Described in L<perlsub>.
316 arbitrarily nested data structures and anonymous functions
318 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
322 object-oriented programming
324 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
329 support for light-weight processes (threads)
331 Described in L<perlthrtut> and L<threads>.
335 support for Unicode, internationalization, and localization
337 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
343 Described in L<perlsub>.
347 regular expression enhancements
349 Described in L<perlre>, with additional examples in L<perlop>.
353 enhanced debugger and interactive Perl environment,
354 with integrated editor support
356 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
360 POSIX 1003.1 compliant library
362 Described in L<POSIX>.
366 Okay, that's I<definitely> enough hype.
370 Perl is available for most operating systems, including virtually
371 all Unix-like platforms. See L<perlport/"Supported Platforms">
380 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
382 If your Perl success stories and testimonials may be of help to others
383 who wish to advocate the use of Perl in their applications,
384 or if you wish to simply express your gratitude to Larry and the
385 Perl developers, please write to perl-thanks@perl.org .
389 "@INC" locations of perl libraries
393 a2p awk to perl translator
394 s2p sed to perl translator
396 http://www.perl.org/ the Perl homepage
397 http://www.perl.com/ Perl articles (O'Reilly)
398 http://www.cpan.org/ the Comprehensive Perl Archive
399 http://www.pm.org/ the Perl Mongers
403 The C<use warnings> pragma (and the B<-w> switch) produces some
406 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
407 diagnostics> pragma automatically turns Perl's normally terse warnings
408 and errors into these longer forms.
410 Compilation errors will tell you the line number of the error, with an
411 indication of the next token or token type that was to be examined.
412 (In a script passed to Perl via B<-e> switches, each
413 B<-e> is counted as one line.)
415 Setuid scripts have additional constraints that can produce error
416 messages such as "Insecure dependency". See L<perlsec>.
418 Did we mention that you should definitely consider using the B<-w>
423 The B<-w> switch is not mandatory.
425 Perl is at the mercy of your machine's definitions of various
426 operations such as type casting, atof(), and floating-point
427 output with sprintf().
429 If your stdio requires a seek or eof between reads and writes on a
430 particular stream, so does Perl. (This doesn't apply to sysread()
433 While none of the built-in data types have any arbitrary size limits
434 (apart from memory size), there are still a few arbitrary limits: a
435 given variable name may not be longer than 251 characters. Line numbers
436 displayed by diagnostics are internally stored as short integers,
437 so they are limited to a maximum of 65535 (higher numbers usually being
438 affected by wraparound).
440 You may mail your bug reports (be sure to include full configuration
441 information as output by the myconfig program in the perl source
442 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
443 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
444 can be used to help mail in a bug report.
446 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
447 don't tell anyone I said that.
451 The Perl motto is "There's more than one way to do it." Divining
452 how many more is left as an exercise to the reader.
454 The three principal virtues of a programmer are Laziness,
455 Impatience, and Hubris. See the Camel Book for why.