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: declarations, statements, comments 91 perldata Perl data structures 92 perlop Perl expressions: operators, precedence, string literals 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 perldocstyle Perl style guide for core docs 100 perlpodstyle Perl POD style guide 101 perldiag Perl diagnostic messages 102 perldeprecation Perl deprecations 103 perllexwarn Perl warnings and their control 104 perldebug Perl debugging 105 perlvar Perl predefined variables 106 perlre Perl regular expressions, the rest of the story 107 perlrebackslash Perl regular expression backslash sequences 108 perlrecharclass Perl regular expression character classes 109 perlreref Perl regular expressions quick reference 110 perlref Perl references, the rest of the story 111 perlform Perl formats 112 perlobj Perl objects 113 perltie Perl objects hidden behind simple variables 114 perldbmfilter Perl DBM filters 115 perlclass Perl class syntax 116 117 perlipc Perl interprocess communication 118 perlfork Perl fork() information 119 perlnumber Perl number semantics 120 121 perlthrtut Perl threads tutorial 122 123 perlport Perl portability guide 124 perllocale Perl locale support 125 perluniintro Perl Unicode introduction 126 perlunicode Perl Unicode support 127 perlunicook Perl Unicode cookbook 128 perlunifaq Perl Unicode FAQ 129 perluniprops Index of Unicode properties in Perl 130 perlunitut Perl Unicode tutorial 131 perlebcdic Considerations for running Perl on EBCDIC platforms 132 133 perlsec Perl security 134 perlsecpolicy Perl security report handling policy 135 136 perlmod Perl modules: how they work 137 perlmodlib Perl modules: how to write and use 138 perlmodstyle Perl modules: how to write modules with style 139 perlmodinstall Perl modules: how to install from CPAN 140 perlnewmod Perl modules: preparing a new module for distribution 141 perlpragma Perl modules: writing a user pragma 142 143 perlutil utilities packaged with the Perl distribution 144 145 perlfilter Perl source filters 146 147 perldtrace Perl's support for DTrace 148 149 perlglossary Perl Glossary 150 151=head2 Internals and C Language Interface 152 153 perlembed Perl ways to embed perl in your C or C++ application 154 perldebguts Perl debugging guts and tips 155 perlxstut Perl XS tutorial 156 perlxs Perl XS application programming interface 157 perlxstypemap Perl XS C/Perl type conversion tools 158 perlclib Interacting with standard C library functions 159 perlguts Perl internal functions for those doing extensions 160 perlcall Perl calling conventions from C 161 perlmroapi Perl method resolution plugin interface 162 perlreapi Perl regular expression plugin interface 163 perlreguts Perl regular expression engine internals 164 perlclassguts Internals of class syntax 165 166 perlapi Perl API listing (autogenerated) 167 perlintern Perl internal functions (autogenerated) 168 perliol C API for Perl's implementation of IO in Layers 169 perlapio Perl internal IO abstraction interface 170 171 perlhack Perl hackers guide 172 perlsource Guide to the Perl source tree 173 perlinterp Overview of the Perl interpreter source and how it works 174 perlhacktut Walk through the creation of a simple C code patch 175 perlhacktips Tips for Perl core C code hacking 176 perlpolicy Perl development policies 177 perlgov Perl Rules of Governance 178 perlgit Using git with the Perl repository 179 180=head2 History 181 182 perlhist Perl history records 183 perldelta Perl changes since previous version 184 perl5400delta Perl changes in version 5.40.0 185 perl5382delta Perl changes in version 5.38.2 186 perl5381delta Perl changes in version 5.38.1 187 perl5380delta Perl changes in version 5.38.0 188 perl5363delta Perl changes in version 5.36.3 189 perl5362delta Perl changes in version 5.36.2 190 perl5361delta Perl changes in version 5.36.1 191 perl5360delta Perl changes in version 5.36.0 192 perl5343delta Perl changes in version 5.34.3 193 perl5342delta Perl changes in version 5.34.2 194 perl5341delta Perl changes in version 5.34.1 195 perl5340delta Perl changes in version 5.34.0 196 perl5321delta Perl changes in version 5.32.1 197 perl5320delta Perl changes in version 5.32.0 198 perl5303delta Perl changes in version 5.30.3 199 perl5302delta Perl changes in version 5.30.2 200 perl5301delta Perl changes in version 5.30.1 201 perl5300delta Perl changes in version 5.30.0 202 perl5283delta Perl changes in version 5.28.3 203 perl5282delta Perl changes in version 5.28.2 204 perl5281delta Perl changes in version 5.28.1 205 perl5280delta Perl changes in version 5.28.0 206 perl5263delta Perl changes in version 5.26.3 207 perl5262delta Perl changes in version 5.26.2 208 perl5261delta Perl changes in version 5.26.1 209 perl5260delta Perl changes in version 5.26.0 210 perl5244delta Perl changes in version 5.24.4 211 perl5243delta Perl changes in version 5.24.3 212 perl5242delta Perl changes in version 5.24.2 213 perl5241delta Perl changes in version 5.24.1 214 perl5240delta Perl changes in version 5.24.0 215 perl5224delta Perl changes in version 5.22.4 216 perl5223delta Perl changes in version 5.22.3 217 perl5222delta Perl changes in version 5.22.2 218 perl5221delta Perl changes in version 5.22.1 219 perl5220delta Perl changes in version 5.22.0 220 perl5203delta Perl changes in version 5.20.3 221 perl5202delta Perl changes in version 5.20.2 222 perl5201delta Perl changes in version 5.20.1 223 perl5200delta Perl changes in version 5.20.0 224 perl5184delta Perl changes in version 5.18.4 225 perl5182delta Perl changes in version 5.18.2 226 perl5181delta Perl changes in version 5.18.1 227 perl5180delta Perl changes in version 5.18.0 228 perl5163delta Perl changes in version 5.16.3 229 perl5162delta Perl changes in version 5.16.2 230 perl5161delta Perl changes in version 5.16.1 231 perl5160delta Perl changes in version 5.16.0 232 perl5144delta Perl changes in version 5.14.4 233 perl5143delta Perl changes in version 5.14.3 234 perl5142delta Perl changes in version 5.14.2 235 perl5141delta Perl changes in version 5.14.1 236 perl5140delta Perl changes in version 5.14.0 237 perl5125delta Perl changes in version 5.12.5 238 perl5124delta Perl changes in version 5.12.4 239 perl5123delta Perl changes in version 5.12.3 240 perl5122delta Perl changes in version 5.12.2 241 perl5121delta Perl changes in version 5.12.1 242 perl5120delta Perl changes in version 5.12.0 243 perl5101delta Perl changes in version 5.10.1 244 perl5100delta Perl changes in version 5.10.0 245 perl589delta Perl changes in version 5.8.9 246 perl588delta Perl changes in version 5.8.8 247 perl587delta Perl changes in version 5.8.7 248 perl586delta Perl changes in version 5.8.6 249 perl585delta Perl changes in version 5.8.5 250 perl584delta Perl changes in version 5.8.4 251 perl583delta Perl changes in version 5.8.3 252 perl582delta Perl changes in version 5.8.2 253 perl581delta Perl changes in version 5.8.1 254 perl58delta Perl changes in version 5.8.0 255 perl561delta Perl changes in version 5.6.1 256 perl56delta Perl changes in version 5.6 257 perl5005delta Perl changes in version 5.005 258 perl5004delta Perl changes in version 5.004 259 260=head2 Miscellaneous 261 262 perlbook Perl book information 263 perlcommunity Perl community information 264 265 perldoc Look up Perl documentation in Pod format 266 267 perlexperiment A listing of experimental features in Perl 268 269 perlartistic Perl Artistic License 270 perlgpl GNU General Public License 271 272=head2 Language-Specific 273 274=for buildtoc flag +r 275 276 perlcn Perl for Simplified Chinese (in UTF-8) 277 perljp Perl for Japanese (in EUC-JP) 278 perlko Perl for Korean (in EUC-KR) 279 perltw Perl for Traditional Chinese (in Big5) 280 281=head2 Platform-Specific 282 283 perlaix Perl notes for AIX 284 perlamiga Perl notes for AmigaOS 285 perlandroid Perl notes for Android 286 perlbs2000 Perl notes for POSIX-BC BS2000 287 perlcygwin Perl notes for Cygwin 288 perlfreebsd Perl notes for FreeBSD 289 perlhaiku Perl notes for Haiku 290 perlhpux Perl notes for HP-UX 291 perlhurd Perl notes for Hurd 292 perlirix Perl notes for Irix 293 perllinux Perl notes for Linux 294 perlmacosx Perl notes for Mac OS X 295 perlopenbsd Perl notes for OpenBSD 296 perlos2 Perl notes for OS/2 297 perlos390 Perl notes for OS/390 298 perlos400 Perl notes for OS/400 299 perlplan9 Perl notes for Plan 9 300 perlqnx Perl notes for QNX 301 perlriscos Perl notes for RISC OS 302 perlsolaris Perl notes for Solaris 303 perlsynology Perl notes for Synology 304 perltru64 Perl notes for Tru64 305 perlvms Perl notes for VMS 306 perlvos Perl notes for Stratus VOS 307 perlwin32 Perl notes for Windows 308 309=for buildtoc flag -r 310 311=head2 Stubs for Deleted Documents 312 313 perlboot 314 perlbot 315 perlrepository 316 perltodo 317 perltooc 318 perltoot 319 320=for buildtoc __END__ 321 322On a Unix-like system, these documentation files will usually also be 323available as manpages for use with the F<man> program. 324 325Some documentation is not available as man pages, so if a 326cross-reference is not found by man, try it with L<perldoc>. Perldoc can 327also take you directly to documentation for functions (with the B<-f> 328switch). See S<C<perldoc --help>> (or S<C<perldoc perldoc>> or 329S<C<man perldoc>>) for other helpful options L<perldoc> has to offer. 330 331In general, if something strange has gone wrong with your program and you're 332not sure where you should look for help, try making your code comply with 333B<use strict> and B<use warnings>. These will often point out exactly 334where the trouble is. 335 336=head1 DESCRIPTION 337 338Perl officially stands for Practical Extraction and Report Language, 339except when it doesn't. 340 341Perl was originally a language optimized for scanning arbitrary 342text files, extracting information from those text files, and printing 343reports based on that information. It quickly became a good language 344for many system management tasks. Over the years, Perl has grown into 345a general-purpose programming language. It's widely used for everything 346from quick "one-liners" to full-scale application development. 347 348The language is intended to be practical (easy to use, efficient, 349complete) rather than beautiful (tiny, elegant, minimal). It combines 350(in the author's opinion, anyway) some of the best features of B<sed>, 351B<awk>, and B<sh>, making it familiar and easy to use for Unix users to 352whip up quick solutions to annoying problems. Its general-purpose 353programming facilities support procedural, functional, and 354object-oriented programming paradigms, making Perl a comfortable 355language for the long haul on major projects, whatever your bent. 356 357Perl's roots in text processing haven't been forgotten over the years. 358It still boasts some of the most powerful regular expressions to be 359found anywhere, and its support for Unicode text is world-class. It 360handles all kinds of structured text, too, through an extensive 361collection of extensions. Those libraries, collected in the CPAN, 362provide ready-made solutions to an astounding array of problems. When 363they haven't set the standard themselves, they steal from the best 364-- just like Perl itself. 365 366=head1 AVAILABILITY 367 368Perl is available for most operating systems, including virtually 369all Unix-like platforms. See L<perlport/"Supported Platforms"> 370for a listing. 371 372=head1 ENVIRONMENT 373 374See L<perlrun/ENVIRONMENT>. 375 376=head1 AUTHOR 377 378Larry Wall <larry@wall.org>, with the help of oodles of other folks. 379 380If your Perl success stories and testimonials may be of help to others 381who wish to advocate the use of Perl in their applications, 382or if you wish to simply express your gratitude to Larry and the 383Perl developers, please write to perl-thanks@perl.org . 384 385=head1 FILES 386 387 "@INC" locations of perl libraries 388 389"@INC" above is a reference to the built-in variable of the same name; 390see L<perlvar> for more information. 391 392=head1 SEE ALSO 393 394=over 395 396=item L<https://www.perl.org/> 397 398the Perl homepage 399 400=item L<https://www.perl.com/> 401 402Perl articles 403 404=item L<https://www.cpan.org/> 405 406the Comprehensive Perl Archive 407 408=item L<https://www.pm.org/> 409 410the Perl Mongers 411 412=back 413 414=head1 DIAGNOSTICS 415 416Using the C<use strict> pragma ensures that all variables are properly 417declared and prevents other misuses of legacy Perl features. 418These are enabled by default within the scope of 419C<L<use v5.12|perlfunc/use VERSION>> (or higher). 420 421The C<use warnings> pragma produces some lovely diagnostics. 422It is enabled by default when you say C<use v5.35> (or higher). 423One can also use the B<-w> flag, but its use is normally discouraged, 424because it gets applied to all executed Perl code, including that not under 425your control. 426 427See L<perldiag> for explanations of all Perl's diagnostics. The C<use 428diagnostics> pragma automatically turns Perl's normally terse warnings 429and errors into these longer forms. 430 431Compilation errors will tell you the line number of the error, with an 432indication of the next token or token type that was to be examined. 433(In a script passed to Perl via B<-e> switches, each 434B<-e> is counted as one line.) 435 436Setuid scripts have additional constraints that can produce error 437messages such as "Insecure dependency". See L<perlsec>. 438 439Did we mention that you should definitely consider using the B<use warnings> 440pragma? 441 442=head1 BUGS 443 444The behavior implied by the B<use warnings> pragma is not mandatory. 445 446Perl is at the mercy of your machine's definitions of various 447operations such as type casting, atof(), and floating-point 448output with sprintf(). 449 450If your stdio requires a seek or eof between reads and writes on a 451particular stream, so does Perl. (This doesn't apply to sysread() 452and syswrite().) 453 454While none of the built-in data types have any arbitrary size limits 455(apart from memory size), there are still a few arbitrary limits: a 456given variable name may not be longer than 251 characters. Line numbers 457displayed by diagnostics are internally stored as short integers, 458so they are limited to a maximum of 65535 (higher numbers usually being 459affected by wraparound). 460 461You may submit your bug reports (be sure to include full configuration 462information as output by the myconfig program in the perl source 463tree, or by C<perl -V>) to L<https://github.com/Perl/perl5/issues>. 464 465Perl actually stands for Pathologically Eclectic Rubbish Lister, but 466don't tell anyone I said that. 467 468=head1 NOTES 469 470The Perl motto is "There's more than one way to do it." Divining 471how many more is left as an exercise to the reader. 472 473The three principal virtues of a programmer are Laziness, 474Impatience, and Hubris. See the Camel Book for why. 475 476