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