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<https://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 perlsecpolicy Perl security report handling policy 133 134 perlmod Perl modules: how they work 135 perlmodlib Perl modules: how to write and use 136 perlmodstyle Perl modules: how to write modules with style 137 perlmodinstall Perl modules: how to install from CPAN 138 perlnewmod Perl modules: preparing a new module for distribution 139 perlpragma Perl modules: writing a user pragma 140 141 perlutil utilities packaged with the Perl distribution 142 143 perlfilter Perl source filters 144 145 perldtrace Perl's support for DTrace 146 147 perlglossary Perl Glossary 148 149=head2 Internals and C Language Interface 150 151 perlembed Perl ways to embed perl in your C or C++ application 152 perldebguts Perl debugging guts and tips 153 perlxstut Perl XS tutorial 154 perlxs Perl XS application programming interface 155 perlxstypemap Perl XS C/Perl type conversion tools 156 perlclib Internal replacements for standard C library functions 157 perlguts Perl internal functions for those doing extensions 158 perlcall Perl calling conventions from C 159 perlmroapi Perl method resolution plugin interface 160 perlreapi Perl regular expression plugin interface 161 perlreguts Perl regular expression engine internals 162 163 perlapi Perl API listing (autogenerated) 164 perlintern Perl internal functions (autogenerated) 165 perliol C API for Perl's implementation of IO in Layers 166 perlapio Perl internal IO abstraction interface 167 168 perlhack Perl hackers guide 169 perlsource Guide to the Perl source tree 170 perlinterp Overview of the Perl interpreter source and how it works 171 perlhacktut Walk through the creation of a simple C code patch 172 perlhacktips Tips for Perl core C code hacking 173 perlpolicy Perl development policies 174 perlgov Perl Rules of Governance 175 perlgit Using git with the Perl repository 176 177=head2 Miscellaneous 178 179 perlbook Perl book information 180 perlcommunity Perl community information 181 182 perldoc Look up Perl documentation in Pod format 183 184 perlhist Perl history records 185 perldelta Perl changes since previous version 186 perl5320delta Perl changes in version 5.32.0 187 perl5303delta Perl changes in version 5.30.3 188 perl5302delta Perl changes in version 5.30.2 189 perl5301delta Perl changes in version 5.30.1 190 perl5300delta Perl changes in version 5.30.0 191 perl5283delta Perl changes in version 5.28.3 192 perl5282delta Perl changes in version 5.28.2 193 perl5281delta Perl changes in version 5.28.1 194 perl5280delta Perl changes in version 5.28.0 195 perl5263delta Perl changes in version 5.26.3 196 perl5262delta Perl changes in version 5.26.2 197 perl5261delta Perl changes in version 5.26.1 198 perl5260delta Perl changes in version 5.26.0 199 perl5244delta Perl changes in version 5.24.4 200 perl5243delta Perl changes in version 5.24.3 201 perl5242delta Perl changes in version 5.24.2 202 perl5241delta Perl changes in version 5.24.1 203 perl5240delta Perl changes in version 5.24.0 204 perl5224delta Perl changes in version 5.22.4 205 perl5223delta Perl changes in version 5.22.3 206 perl5222delta Perl changes in version 5.22.2 207 perl5221delta Perl changes in version 5.22.1 208 perl5220delta Perl changes in version 5.22.0 209 perl5203delta Perl changes in version 5.20.3 210 perl5202delta Perl changes in version 5.20.2 211 perl5201delta Perl changes in version 5.20.1 212 perl5200delta Perl changes in version 5.20.0 213 perl5184delta Perl changes in version 5.18.4 214 perl5182delta Perl changes in version 5.18.2 215 perl5181delta Perl changes in version 5.18.1 216 perl5180delta Perl changes in version 5.18.0 217 perl5163delta Perl changes in version 5.16.3 218 perl5162delta Perl changes in version 5.16.2 219 perl5161delta Perl changes in version 5.16.1 220 perl5160delta Perl changes in version 5.16.0 221 perl5144delta Perl changes in version 5.14.4 222 perl5143delta Perl changes in version 5.14.3 223 perl5142delta Perl changes in version 5.14.2 224 perl5141delta Perl changes in version 5.14.1 225 perl5140delta Perl changes in version 5.14.0 226 perl5125delta Perl changes in version 5.12.5 227 perl5124delta Perl changes in version 5.12.4 228 perl5123delta Perl changes in version 5.12.3 229 perl5122delta Perl changes in version 5.12.2 230 perl5121delta Perl changes in version 5.12.1 231 perl5120delta Perl changes in version 5.12.0 232 perl5101delta Perl changes in version 5.10.1 233 perl5100delta Perl changes in version 5.10.0 234 perl589delta Perl changes in version 5.8.9 235 perl588delta Perl changes in version 5.8.8 236 perl587delta Perl changes in version 5.8.7 237 perl586delta Perl changes in version 5.8.6 238 perl585delta Perl changes in version 5.8.5 239 perl584delta Perl changes in version 5.8.4 240 perl583delta Perl changes in version 5.8.3 241 perl582delta Perl changes in version 5.8.2 242 perl581delta Perl changes in version 5.8.1 243 perl58delta Perl changes in version 5.8.0 244 perl561delta Perl changes in version 5.6.1 245 perl56delta Perl changes in version 5.6 246 perl5005delta Perl changes in version 5.005 247 perl5004delta Perl changes in version 5.004 248 249 perlexperiment A listing of experimental features in Perl 250 251 perlartistic Perl Artistic License 252 perlgpl GNU General Public License 253 254=head2 Language-Specific 255 256=for buildtoc flag +r 257 258 perlcn Perl for Simplified Chinese (in EUC-CN) 259 perljp Perl for Japanese (in EUC-JP) 260 perlko Perl for Korean (in EUC-KR) 261 perltw Perl for Traditional Chinese (in Big5) 262 263=head2 Platform-Specific 264 265 perlaix Perl notes for AIX 266 perlamiga Perl notes for AmigaOS 267 perlandroid Perl notes for Android 268 perlbs2000 Perl notes for POSIX-BC BS2000 269 perlcygwin Perl notes for Cygwin 270 perldos Perl notes for DOS 271 perlfreebsd Perl notes for FreeBSD 272 perlhaiku Perl notes for Haiku 273 perlhpux Perl notes for HP-UX 274 perlhurd Perl notes for Hurd 275 perlirix Perl notes for Irix 276 perllinux Perl notes for Linux 277 perlmacos Perl notes for Mac OS (Classic) 278 perlmacosx Perl notes for Mac OS X 279 perlnetware Perl notes for NetWare 280 perlopenbsd Perl notes for OpenBSD 281 perlos2 Perl notes for OS/2 282 perlos390 Perl notes for OS/390 283 perlos400 Perl notes for OS/400 284 perlplan9 Perl notes for Plan 9 285 perlqnx Perl notes for QNX 286 perlriscos Perl notes for RISC OS 287 perlsolaris Perl notes for Solaris 288 perlsymbian Perl notes for Symbian 289 perlsynology Perl notes for Synology 290 perltru64 Perl notes for Tru64 291 perlvms Perl notes for VMS 292 perlvos Perl notes for Stratus VOS 293 perlwin32 Perl notes for Windows 294 295=for buildtoc flag -r 296 297=head2 Stubs for Deleted Documents 298 299 perlboot 300 perlbot 301 perlrepository 302 perltodo 303 perltooc 304 perltoot 305 306=for buildtoc __END__ 307 308On a Unix-like system, these documentation files will usually also be 309available as manpages for use with the F<man> program. 310 311Some documentation is not available as man pages, so if a 312cross-reference is not found by man, try it with L<perldoc>. Perldoc can 313also take you directly to documentation for functions (with the B<-f> 314switch). See C<perldoc --help> (or C<perldoc perldoc> or C<man perldoc>) 315for other helpful options L<perldoc> has to offer. 316 317In general, if something strange has gone wrong with your program and you're 318not sure where you should look for help, try making your code comply with 319B<use strict> and B<use warnings>. These will often point out exactly 320where the trouble is. 321 322=head1 DESCRIPTION 323 324Perl officially stands for Practical Extraction and Report Language, 325except when it doesn't. 326 327Perl was originally a language optimized for scanning arbitrary 328text files, extracting information from those text files, and printing 329reports based on that information. It quickly became a good language 330for many system management tasks. Over the years, Perl has grown into 331a general-purpose programming language. It's widely used for everything 332from quick "one-liners" to full-scale application development. 333 334The language is intended to be practical (easy to use, efficient, 335complete) rather than beautiful (tiny, elegant, minimal). It combines 336(in the author's opinion, anyway) some of the best features of B<sed>, 337B<awk>, and B<sh>, making it familiar and easy to use for Unix users to 338whip up quick solutions to annoying problems. Its general-purpose 339programming facilities support procedural, functional, and 340object-oriented programming paradigms, making Perl a comfortable 341language for the long haul on major projects, whatever your bent. 342 343Perl's roots in text processing haven't been forgotten over the years. 344It still boasts some of the most powerful regular expressions to be 345found anywhere, and its support for Unicode text is world-class. It 346handles all kinds of structured text, too, through an extensive 347collection of extensions. Those libraries, collected in the CPAN, 348provide ready-made solutions to an astounding array of problems. When 349they haven't set the standard themselves, they steal from the best 350-- just like Perl itself. 351 352=head1 AVAILABILITY 353 354Perl is available for most operating systems, including virtually 355all Unix-like platforms. See L<perlport/"Supported Platforms"> 356for a listing. 357 358=head1 ENVIRONMENT 359 360See L<perlrun/ENVIRONMENT>. 361 362=head1 AUTHOR 363 364Larry Wall <larry@wall.org>, with the help of oodles of other folks. 365 366If your Perl success stories and testimonials may be of help to others 367who wish to advocate the use of Perl in their applications, 368or if you wish to simply express your gratitude to Larry and the 369Perl developers, please write to perl-thanks@perl.org . 370 371=head1 FILES 372 373 "@INC" locations of perl libraries 374 375"@INC" above is a reference to the built-in variable of the same name; 376see L<perlvar> for more information. 377 378=head1 SEE ALSO 379 380 https://www.perl.org/ the Perl homepage 381 https://www.perl.com/ Perl articles 382 https://www.cpan.org/ the Comprehensive Perl Archive 383 https://www.pm.org/ the Perl Mongers 384 385=head1 DIAGNOSTICS 386 387Using the C<use strict> pragma ensures that all variables are properly 388declared and prevents other misuses of legacy Perl features. 389 390The C<use warnings> pragma produces some lovely diagnostics. One can 391also use the B<-w> flag, but its use is normally discouraged, because 392it gets applied to all executed Perl code, including that not under 393your control. 394 395See L<perldiag> for explanations of all Perl's diagnostics. The C<use 396diagnostics> pragma automatically turns Perl's normally terse warnings 397and errors into these longer forms. 398 399Compilation errors will tell you the line number of the error, with an 400indication of the next token or token type that was to be examined. 401(In a script passed to Perl via B<-e> switches, each 402B<-e> is counted as one line.) 403 404Setuid scripts have additional constraints that can produce error 405messages such as "Insecure dependency". See L<perlsec>. 406 407Did we mention that you should definitely consider using the B<use warnings> 408pragma? 409 410=head1 BUGS 411 412The behavior implied by the B<use warnings> pragma is not mandatory. 413 414Perl is at the mercy of your machine's definitions of various 415operations such as type casting, atof(), and floating-point 416output with sprintf(). 417 418If your stdio requires a seek or eof between reads and writes on a 419particular stream, so does Perl. (This doesn't apply to sysread() 420and syswrite().) 421 422While none of the built-in data types have any arbitrary size limits 423(apart from memory size), there are still a few arbitrary limits: a 424given variable name may not be longer than 251 characters. Line numbers 425displayed by diagnostics are internally stored as short integers, 426so they are limited to a maximum of 65535 (higher numbers usually being 427affected by wraparound). 428 429You may submit your bug reports (be sure to include full configuration 430information as output by the myconfig program in the perl source 431tree, or by C<perl -V>) to L<https://github.com/Perl/perl5/issues>. 432 433Perl actually stands for Pathologically Eclectic Rubbish Lister, but 434don't tell anyone I said that. 435 436=head1 NOTES 437 438The Perl motto is "There's more than one way to do it." Divining 439how many more is left as an exercise to the reader. 440 441The three principal virtues of a programmer are Laziness, 442Impatience, and Hubris. See the Camel Book for why. 443 444