1=head1 NAME 2 3perl - The Perl 5 language interpreter 4 5=head1 SYNOPSIS 6 7B<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<-C [I<number/list>] >]> 13 S<[ B<-S> ]> 14 S<[ B<-x>[I<dir>] ]> 15 S<[ B<-i>[I<extension>] ]> 16 S<[ [B<-e>|B<-E>] I<'command'> ] [ B<--> ] [ I<programfile> ] [ I<argument> ]...> 17 18For more information on these options, you can run C<perldoc perlrun>. 19 20=head1 GETTING HELP 21 22The F<perldoc> program gives you access to all the documentation that comes 23with Perl. You can get more documentation, tutorials and community support 24online at L<http://www.perl.org/>. 25 26If you're new to Perl, you should start by running C<perldoc perlintro>, 27which is a general intro for beginners and provides some background to help 28you navigate the rest of Perl's extensive documentation. Run C<perldoc 29perldoc> to learn more things you can do with F<perldoc>. 30 31For ease of access, the Perl manual has been split up into several sections. 32 33=begin buildtoc 34 35# This section is parsed by Porting/pod_lib.pl for use by pod/buildtoc etc 36 37flag =g perlmodlib perlapi perlintern 38flag =go perltoc 39flag =ro perlcn perljp perlko perltw 40flag = perlvms 41 42path perlfaq.* cpan/perlfaq/lib/ 43path perlglossary cpan/perlfaq/lib/ 44path perlxs(?:tut|typemap)? dist/ExtUtils-ParseXS/lib/ 45path perldoc cpan/Pod-Perldoc/ 46 47aux h2ph h2xs perlbug pl2pm pod2html pod2man splain xsubpp 48 49=end buildtoc 50 51=head2 Overview 52 53 perl Perl overview (this section) 54 perlintro Perl introduction for beginners 55 perlrun Perl execution and options 56 perltoc Perl documentation table of contents 57 58=head2 Tutorials 59 60 perlreftut Perl references short introduction 61 perldsc Perl data structures intro 62 perllol Perl data structures: arrays of arrays 63 64 perlrequick Perl regular expressions quick start 65 perlretut Perl regular expressions tutorial 66 67 perlootut Perl OO tutorial for beginners 68 69 perlperf Perl Performance and Optimization Techniques 70 71 perlstyle Perl style guide 72 73 perlcheat Perl cheat sheet 74 perltrap Perl traps for the unwary 75 perldebtut Perl debugging tutorial 76 77 perlfaq Perl frequently asked questions 78 perlfaq1 General Questions About Perl 79 perlfaq2 Obtaining and Learning about Perl 80 perlfaq3 Programming Tools 81 perlfaq4 Data Manipulation 82 perlfaq5 Files and Formats 83 perlfaq6 Regexes 84 perlfaq7 Perl Language Issues 85 perlfaq8 System Interaction 86 perlfaq9 Networking 87 88=head2 Reference Manual 89 90 perlsyn Perl syntax 91 perldata Perl data structures 92 perlop Perl operators and precedence 93 perlsub Perl subroutines 94 perlfunc Perl built-in functions 95 perlopentut Perl open() tutorial 96 perlpacktut Perl pack() and unpack() tutorial 97 perlpod Perl plain old documentation 98 perlpodspec Perl plain old documentation format specification 99 perlpodstyle Perl POD style guide 100 perldiag Perl diagnostic messages 101 perldeprecation Perl deprecations 102 perllexwarn Perl warnings and their control 103 perldebug Perl debugging 104 perlvar Perl predefined variables 105 perlre Perl regular expressions, the rest of the story 106 perlrebackslash Perl regular expression backslash sequences 107 perlrecharclass Perl regular expression character classes 108 perlreref Perl regular expressions quick reference 109 perlref Perl references, the rest of the story 110 perlform Perl formats 111 perlobj Perl objects 112 perltie Perl objects hidden behind simple variables 113 perldbmfilter Perl DBM filters 114 115 perlipc Perl interprocess communication 116 perlfork Perl fork() information 117 perlnumber Perl number semantics 118 119 perlthrtut Perl threads tutorial 120 121 perlport Perl portability guide 122 perllocale Perl locale support 123 perluniintro Perl Unicode introduction 124 perlunicode Perl Unicode support 125 perlunicook Perl Unicode cookbook 126 perlunifaq Perl Unicode FAQ 127 perluniprops Index of Unicode properties in Perl 128 perlunitut Perl Unicode tutorial 129 perlebcdic Considerations for running Perl on EBCDIC platforms 130 131 perlsec Perl security 132 133 perlmod Perl modules: how they work 134 perlmodlib Perl modules: how to write and use 135 perlmodstyle Perl modules: how to write modules with style 136 perlmodinstall Perl modules: how to install from CPAN 137 perlnewmod Perl modules: preparing a new module for distribution 138 perlpragma Perl modules: writing a user pragma 139 140 perlutil utilities packaged with the Perl distribution 141 142 perlfilter Perl source filters 143 144 perldtrace Perl's support for DTrace 145 146 perlglossary Perl Glossary 147 148=head2 Internals and C Language Interface 149 150 perlembed Perl ways to embed perl in your C or C++ application 151 perldebguts Perl debugging guts and tips 152 perlxstut Perl XS tutorial 153 perlxs Perl XS application programming interface 154 perlxstypemap Perl XS C/Perl type conversion tools 155 perlclib Internal replacements for standard C library functions 156 perlguts Perl internal functions for those doing extensions 157 perlcall Perl calling conventions from C 158 perlmroapi Perl method resolution plugin interface 159 perlreapi Perl regular expression plugin interface 160 perlreguts Perl regular expression engine internals 161 162 perlapi Perl API listing (autogenerated) 163 perlintern Perl internal functions (autogenerated) 164 perliol C API for Perl's implementation of IO in Layers 165 perlapio Perl internal IO abstraction interface 166 167 perlhack Perl hackers guide 168 perlsource Guide to the Perl source tree 169 perlinterp Overview of the Perl interpreter source and how it works 170 perlhacktut Walk through the creation of a simple C code patch 171 perlhacktips Tips for Perl core C code hacking 172 perlpolicy Perl development policies 173 perlgit Using git with the Perl repository 174 175=head2 Miscellaneous 176 177 perlbook Perl book information 178 perlcommunity Perl community information 179 180 perldoc Look up Perl documentation in Pod format 181 182 perlhist Perl history records 183 perldelta Perl changes since previous version 184 perl5300delta Perl changes in version 5.30.0 185 perl5282delta Perl changes in version 5.28.2 186 perl5281delta Perl changes in version 5.28.1 187 perl5280delta Perl changes in version 5.28.0 188 perl5263delta Perl changes in version 5.26.3 189 perl5262delta Perl changes in version 5.26.2 190 perl5261delta Perl changes in version 5.26.1 191 perl5260delta Perl changes in version 5.26.0 192 perl5244delta Perl changes in version 5.24.4 193 perl5243delta Perl changes in version 5.24.3 194 perl5242delta Perl changes in version 5.24.2 195 perl5241delta Perl changes in version 5.24.1 196 perl5240delta Perl changes in version 5.24.0 197 perl5224delta Perl changes in version 5.22.4 198 perl5223delta Perl changes in version 5.22.3 199 perl5222delta Perl changes in version 5.22.2 200 perl5221delta Perl changes in version 5.22.1 201 perl5220delta Perl changes in version 5.22.0 202 perl5203delta Perl changes in version 5.20.3 203 perl5202delta Perl changes in version 5.20.2 204 perl5201delta Perl changes in version 5.20.1 205 perl5200delta Perl changes in version 5.20.0 206 perl5184delta Perl changes in version 5.18.4 207 perl5182delta Perl changes in version 5.18.2 208 perl5181delta Perl changes in version 5.18.1 209 perl5180delta Perl changes in version 5.18.0 210 perl5163delta Perl changes in version 5.16.3 211 perl5162delta Perl changes in version 5.16.2 212 perl5161delta Perl changes in version 5.16.1 213 perl5160delta Perl changes in version 5.16.0 214 perl5144delta Perl changes in version 5.14.4 215 perl5143delta Perl changes in version 5.14.3 216 perl5142delta Perl changes in version 5.14.2 217 perl5141delta Perl changes in version 5.14.1 218 perl5140delta Perl changes in version 5.14.0 219 perl5125delta Perl changes in version 5.12.5 220 perl5124delta Perl changes in version 5.12.4 221 perl5123delta Perl changes in version 5.12.3 222 perl5122delta Perl changes in version 5.12.2 223 perl5121delta Perl changes in version 5.12.1 224 perl5120delta Perl changes in version 5.12.0 225 perl5101delta Perl changes in version 5.10.1 226 perl5100delta Perl changes in version 5.10.0 227 perl589delta Perl changes in version 5.8.9 228 perl588delta Perl changes in version 5.8.8 229 perl587delta Perl changes in version 5.8.7 230 perl586delta Perl changes in version 5.8.6 231 perl585delta Perl changes in version 5.8.5 232 perl584delta Perl changes in version 5.8.4 233 perl583delta Perl changes in version 5.8.3 234 perl582delta Perl changes in version 5.8.2 235 perl581delta Perl changes in version 5.8.1 236 perl58delta Perl changes in version 5.8.0 237 perl561delta Perl changes in version 5.6.1 238 perl56delta Perl changes in version 5.6 239 perl5005delta Perl changes in version 5.005 240 perl5004delta Perl changes in version 5.004 241 242 perlexperiment A listing of experimental features in Perl 243 244 perlartistic Perl Artistic License 245 perlgpl GNU General Public License 246 247=head2 Language-Specific 248 249=for buildtoc flag +r 250 251 perlcn Perl for Simplified Chinese (in EUC-CN) 252 perljp Perl for Japanese (in EUC-JP) 253 perlko Perl for Korean (in EUC-KR) 254 perltw Perl for Traditional Chinese (in Big5) 255 256=head2 Platform-Specific 257 258 perlaix Perl notes for AIX 259 perlamiga Perl notes for AmigaOS 260 perlandroid Perl notes for Android 261 perlbs2000 Perl notes for POSIX-BC BS2000 262 perlce Perl notes for WinCE 263 perlcygwin Perl notes for Cygwin 264 perldos Perl notes for DOS 265 perlfreebsd Perl notes for FreeBSD 266 perlhaiku Perl notes for Haiku 267 perlhpux Perl notes for HP-UX 268 perlhurd Perl notes for Hurd 269 perlirix Perl notes for Irix 270 perllinux Perl notes for Linux 271 perlmacos Perl notes for Mac OS (Classic) 272 perlmacosx Perl notes for Mac OS X 273 perlnetware Perl notes for NetWare 274 perlopenbsd Perl notes for OpenBSD 275 perlos2 Perl notes for OS/2 276 perlos390 Perl notes for OS/390 277 perlos400 Perl notes for OS/400 278 perlplan9 Perl notes for Plan 9 279 perlqnx Perl notes for QNX 280 perlriscos Perl notes for RISC OS 281 perlsolaris Perl notes for Solaris 282 perlsymbian Perl notes for Symbian 283 perlsynology Perl notes for Synology 284 perltru64 Perl notes for Tru64 285 perlvms Perl notes for VMS 286 perlvos Perl notes for Stratus VOS 287 perlwin32 Perl notes for Windows 288 289=for buildtoc flag -r 290 291=head2 Stubs for Deleted Documents 292 293 perlboot 294 perlbot 295 perlrepository 296 perltodo 297 perltooc 298 perltoot 299 300=for buildtoc __END__ 301 302On a Unix-like system, these documentation files will usually also be 303available as manpages for use with the F<man> program. 304 305Some documentation is not available as man pages, so if a 306cross-reference is not found by man, try it with L<perldoc>. Perldoc can 307also take you directly to documentation for functions (with the B<-f> 308switch). See C<perldoc --help> (or C<perldoc perldoc> or C<man perldoc>) 309for other helpful options L<perldoc> has to offer. 310 311In general, if something strange has gone wrong with your program and you're 312not sure where you should look for help, try making your code comply with 313B<use strict> and B<use warnings>. These will often point out exactly 314where the trouble is. 315 316=head1 DESCRIPTION 317 318Perl officially stands for Practical Extraction and Report Language, 319except when it doesn't. 320 321Perl was originally a language optimized for scanning arbitrary 322text files, extracting information from those text files, and printing 323reports based on that information. It quickly became a good language 324for many system management tasks. Over the years, Perl has grown into 325a general-purpose programming language. It's widely used for everything 326from quick "one-liners" to full-scale application development. 327 328The language is intended to be practical (easy to use, efficient, 329complete) rather than beautiful (tiny, elegant, minimal). It combines 330(in the author's opinion, anyway) some of the best features of B<sed>, 331B<awk>, and B<sh>, making it familiar and easy to use for Unix users to 332whip up quick solutions to annoying problems. Its general-purpose 333programming facilities support procedural, functional, and 334object-oriented programming paradigms, making Perl a comfortable 335language for the long haul on major projects, whatever your bent. 336 337Perl's roots in text processing haven't been forgotten over the years. 338It still boasts some of the most powerful regular expressions to be 339found anywhere, and its support for Unicode text is world-class. It 340handles all kinds of structured text, too, through an extensive 341collection of extensions. Those libraries, collected in the CPAN, 342provide ready-made solutions to an astounding array of problems. When 343they haven't set the standard themselves, they steal from the best 344-- just like Perl itself. 345 346=head1 AVAILABILITY 347 348Perl is available for most operating systems, including virtually 349all Unix-like platforms. See L<perlport/"Supported Platforms"> 350for a listing. 351 352=head1 ENVIRONMENT 353 354See L<perlrun>. 355 356=head1 AUTHOR 357 358Larry Wall <larry@wall.org>, with the help of oodles of other folks. 359 360If your Perl success stories and testimonials may be of help to others 361who wish to advocate the use of Perl in their applications, 362or if you wish to simply express your gratitude to Larry and the 363Perl developers, please write to perl-thanks@perl.org . 364 365=head1 FILES 366 367 "@INC" locations of perl libraries 368 369"@INC" above is a reference to the built-in variable of the same name; 370see L<perlvar> for more information. 371 372=head1 SEE ALSO 373 374 http://www.perl.org/ the Perl homepage 375 http://www.perl.com/ Perl articles (O'Reilly) 376 http://www.cpan.org/ the Comprehensive Perl Archive 377 http://www.pm.org/ the Perl Mongers 378 379=head1 DIAGNOSTICS 380 381Using the C<use strict> pragma ensures that all variables are properly 382declared and prevents other misuses of legacy Perl features. 383 384The C<use warnings> pragma produces some lovely diagnostics. One can 385also use the B<-w> flag, but its use is normally discouraged, because 386it gets applied to all executed Perl code, including that not under 387your control. 388 389See L<perldiag> for explanations of all Perl's diagnostics. The C<use 390diagnostics> pragma automatically turns Perl's normally terse warnings 391and errors into these longer forms. 392 393Compilation errors will tell you the line number of the error, with an 394indication of the next token or token type that was to be examined. 395(In a script passed to Perl via B<-e> switches, each 396B<-e> is counted as one line.) 397 398Setuid scripts have additional constraints that can produce error 399messages such as "Insecure dependency". See L<perlsec>. 400 401Did we mention that you should definitely consider using the B<use warnings> 402pragma? 403 404=head1 BUGS 405 406The behavior implied by the B<use warnings> pragma is not mandatory. 407 408Perl is at the mercy of your machine's definitions of various 409operations such as type casting, atof(), and floating-point 410output with sprintf(). 411 412If your stdio requires a seek or eof between reads and writes on a 413particular stream, so does Perl. (This doesn't apply to sysread() 414and syswrite().) 415 416While none of the built-in data types have any arbitrary size limits 417(apart from memory size), there are still a few arbitrary limits: a 418given variable name may not be longer than 251 characters. Line numbers 419displayed by diagnostics are internally stored as short integers, 420so they are limited to a maximum of 65535 (higher numbers usually being 421affected by wraparound). 422 423You may mail your bug reports (be sure to include full configuration 424information as output by the myconfig program in the perl source 425tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded 426in compiling perl, the L<perlbug> script in the F<utils/> subdirectory 427can be used to help mail in a bug report. 428 429Perl actually stands for Pathologically Eclectic Rubbish Lister, but 430don't tell anyone I said that. 431 432=head1 NOTES 433 434The Perl motto is "There's more than one way to do it." Divining 435how many more is left as an exercise to the reader. 436 437The three principal virtues of a programmer are Laziness, 438Impatience, and Hubris. See the Camel Book for why. 439 440