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