X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=pod%2Fperl.pod;h=7291b847e8c93b27a02404f3df3d5048b04cd6d8;hb=ba58ab2683569fa823a7a9d7799f01b76d4cfe57;hp=99420f703a13ef90bc187f03106b5bb068964dd2;hpb=00ad96e121343df692c8a0377af3c7be84db16f8;p=p5sagit%2Fp5-mst-13.2.git diff --git a/pod/perl.pod b/pod/perl.pod index 99420f7..7291b84 100644 --- a/pod/perl.pod +++ b/pod/perl.pod @@ -4,19 +4,16 @@ perl - Practical Extraction and Report Language =head1 SYNOPSIS -B S<[ B<-sTuU> ]> - S<[ B<-hv> ] [ B<-V>[:I] ]> - S<[ B<-cw> ] [ B<-d>[:I] ] [ B<-D>[I] ]> - S<[ B<-pna> ] [ B<-F>I ] [ B<-l>[I] ] [ B<-0>[I] ]> - S<[ B<-I>I ] [ B<-m>[B<->]I ] [ B<-M>[B<->]I<'module...'> ]> - S<[ B<-P> ]> - S<[ B<-S> ]> - S<[ B<-x>[I] ]> - S<[ B<-i>[I] ]> - S<[ B<-e> I<'command'> ] [ B<--> ] [ I ] [ I ]...> - -For ease of access, the Perl manual has been split up into a number -of sections: +B S<[ B<-sTuU> ]> S<[ B<-hv> ] [ B<-V>[:I] ]> + S<[ B<-cw> ] [ B<-d>[:I] ] [ B<-D>[I] ]> + S<[ B<-pna> ] [ B<-F>I ] [ B<-l>[I] ] [ B<-0>[I] ]> + S<[ B<-I>I ] [ B<-m>[B<->]I ] [ B<-M>[B<->]I<'module...'> ]> + S<[ B<-P> ]> S<[ B<-S> ]> S<[ B<-x>[I] ]> + S<[ B<-i>[I] ]> S<[ B<-e> I<'command'> ] + [ B<--> ] [ I ] [ I ]...> + +For ease of access, the Perl manual has been split up into several +sections: perl Perl overview (this section) perldelta Perl changes since previous version @@ -38,21 +35,30 @@ of sections: perlmodlib Perl modules: how to write and use perlmodinstall Perl modules: how to install from CPAN perlform Perl formats + perlunicode Perl unicode support perllocale Perl locale support - perlref Perl references perlreftut Perl references short introduction + perlref Perl references, the rest of the story perldsc Perl data structures intro - perllol Perl data structures: lists of lists - perltoot Perl OO tutorial + perllol Perl data structures: arrays of arrays + perlboot Perl OO tutorial for beginners + perltoot Perl OO tutorial, part 1 + perltootc Perl OO tutorial, part 2 perlobj Perl objects perltie Perl objects hidden behind simple variables perlbot Perl OO tricks and examples perlipc Perl interprocess communication + perlfork Perl fork() information perlthrtut Perl threads tutorial + perllexwarn Perl warnings and their control + perlfilter Perl source filters + perldbmfilter Perl DBM filters + perlcompile Perl compiler suite intro perldebug Perl debugging perldiag Perl diagnostic messages + perlnumber Perl number semantics perlsec Perl security perltrap Perl traps for the unwary perlport Perl portability guide @@ -67,14 +73,26 @@ of sections: perlxstut Perl XS tutorial perlguts Perl internal functions for those doing extensions perlcall Perl calling conventions from C + perlapi Perl API listing (autogenerated) + perlintern Perl internal functions (autogenerated) perltodo Perl things to do + perlhack Perl hackers guide perlhist Perl history records + perlamiga Perl notes for Amiga + perlcygwin Perl notes for Cygwin + perldos Perl notes for DOS + perlhpux Perl notes for HP-UX + perlos2 Perl notes for OS/2 + perlos390 Perl notes for OS/390 + perlvms Perl notes for VMS + perlwin32 Perl notes for Windows + (If you're intending to read these straight through for the first time, the suggested order will tend to reduce the number of forward references.) -By default, all of the above manpages are installed in the +By default, the manpages listed above are installed in the F directory. Extensive additional documentation for Perl modules is available. The @@ -118,17 +136,17 @@ Perl combines (in the author's opinion, anyway) some of the best features of C, B, B, and B, so people familiar with those languages should have little difficulty with it. (Language historians will also note some vestiges of B, Pascal, and even -BASIC-PLUS.) Expression syntax corresponds quite closely to C +BASIC-PLUS.) Expression syntax corresponds closely to C expression syntax. Unlike most Unix utilities, Perl does not arbitrarily limit the size of your data--if you've got the memory, Perl can slurp in your whole file as a single string. Recursion is of unlimited depth. And the tables used by hashes (sometimes called "associative arrays") grow as necessary to prevent degraded performance. Perl can use sophisticated pattern matching techniques to -scan large amounts of data very quickly. Although optimized for +scan large amounts of data quickly. Although optimized for scanning text, Perl can also deal with binary data, and can make dbm files look like hashes. Setuid Perl scripts are safer than C programs -through a dataflow tracing mechanism which prevents many stupid +through a dataflow tracing mechanism that prevents many stupid security holes. If you have a problem that would ordinarily use B or B or @@ -139,107 +157,63 @@ scripts into Perl scripts. But wait, there's more... -Perl version 5 is nearly a complete rewrite, and provides -the following additional benefits: - -=over 5 +Begun in 1993 (see L), Perl version 5 is nearly a complete +rewrite that provides the following additional benefits: -=item * Many usability enhancements +=over -It is now possible to write much more readable Perl code (even within -regular expressions). Formerly cryptic variable names can be replaced -by mnemonic identifiers. Error messages are more informative, and the -optional warnings will catch many of the mistakes a novice might make. -This cannot be stressed enough. Whenever you get mysterious behavior, -try the B<-w> switch!!! Whenever you don't get mysterious behavior, -try using B<-w> anyway. +=item * modularity and reusability using innumerable modules -=item * Simplified grammar +Described in L, L, and L. -The new yacc grammar is one half the size of the old one. Many of the -arbitrary grammar rules have been regularized. The number of reserved -words has been cut by 2/3. Despite this, nearly all old Perl scripts -will continue to work unchanged. +=item * embeddable and extensible -=item * Lexical scoping +Described in L, L, L, L, +L, and L. -Perl variables may now be declared within a lexical scope, like "auto" -variables in C. Not only is this more efficient, but it contributes -to better privacy for "programming in the large". Anonymous -subroutines exhibit deep binding of lexical variables (closures). +=item * roll-your-own magic variables (including multiple simultaneous DBM implementations) -=item * Arbitrarily nested data structures +Described in L and L. -Any scalar value, including any array element, may now contain a -reference to any other variable or subroutine. You can easily create -anonymous variables and subroutines. Perl manages your reference -counts for you. +=item * subroutines can now be overridden, autoloaded, and prototyped -=item * Modularity and reusability +Described in L. -The Perl library is now defined in terms of modules which can be easily -shared among various packages. A package may choose to import all or a -portion of a module's published interface. Pragmas (that is, compiler -directives) are defined and used by the same mechanism. +=item * arbitrarily nested data structures and anonymous functions -=item * Object-oriented programming +Described in L, L, L, and L. -A package can function as a class. Dynamic multiple inheritance and -virtual methods are supported in a straightforward manner and with very -little new syntax. Filehandles may now be treated as objects. +=item * object-oriented programming -=item * Embeddable and Extensible +Described in L, L, and L. -Perl may now be embedded easily in your C or C++ application, and can -either call or be called by your routines through a documented -interface. The XS preprocessor is provided to make it easy to glue -your C or C++ routines into Perl. Dynamic loading of modules is -supported, and Perl itself can be made into a dynamic library. +=item * compilability into C code or Perl bytecode -=item * POSIX compliant +Described in L and L. -A major new module is the POSIX module, which provides access to all -available POSIX routines and definitions, via object classes where -appropriate. +=item * support for light-weight processes (threads) -=item * Package constructors and destructors +Described in L and L. -The new BEGIN and END blocks provide means to capture control as -a package is being compiled, and after the program exits. As a -degenerate case they work just like awk's BEGIN and END when you -use the B<-p> or B<-n> switches. +=item * support for internationalization, localization, and Unicode -=item * Multiple simultaneous DBM implementations +Described in L and L. -A Perl program may now access DBM, NDBM, SDBM, GDBM, and Berkeley DB -files from the same script simultaneously. In fact, the old dbmopen -interface has been generalized to allow any variable to be tied -to an object class which defines its access methods. +=item * lexical scoping -=item * Subroutine definitions may now be autoloaded +Described in L. -In fact, the AUTOLOAD mechanism also allows you to define any arbitrary -semantics for undefined subroutine calls. It's not for just autoloading. +=item * regular expression enhancements -=item * Regular expression enhancements +Described in L, with additional examples in L. -You can now specify nongreedy quantifiers. You can now do grouping -without creating a backreference. You can now write regular expressions -with embedded whitespace and comments for readability. A consistent -extensibility mechanism has been added that is upwardly compatible with -all old regular expressions. +=item * enhanced debugger and interactive Perl environment, with integrated editor support -=item * Innumerable Unbundled Modules +Described in L. -The Comprehensive Perl Archive Network described in L -contains hundreds of plug-and-play modules full of reusable code. -See F for a site near you. +=item * POSIX 1003.1 compliant library -=item * Compilability - -While not yet in full production mode, a working perl-to-C compiler -does exist. It can generate portable byte code, simple C, or -optimized C code. +Described in L. =back @@ -247,75 +221,9 @@ Okay, that's I enough hype. =head1 AVAILABILITY -Perl is available for the vast majority of operating system platforms, -including most Unix-like platforms. The following situation is as of -February 1999 and Perl 5.005_03. - -The following platforms are able to build Perl from the standard -source code distribution available at -F - - AIX IRIX SCO ODT/OSR - A/UX Linux Solaris - BeOS MachTen SunOS - BSD/OS MPE/iX SVR4 - DG/UX NetBSD Ultrix - Digital UNIX NextSTEP UNICOS - DOS DJGPP 1) OpenBSD VMS - DYNIX/ptx OpenSTEP Windows 3.1 1) - FreeBSD OS/2 Windows 95 1) 3) - HP-UX OS390 2) Windows 98 1) 3) - Hurd PowerMAX Windows NT 1) 3) - QNX VOS - - 1) in DOS mode either the DOS or OS/2 ports can be used - 2) formerly known as MVS - 3) compilers: Borland, Cygwin32, Mingw32 EGCS/GCC, VC++ - -The following platforms have been known to build Perl from the source -but for the Perl release 5.005_03 we haven't been able to verify them, -either because the hardware/software platforms are rather rare or -because we don't have an active champion on these platforms, or both. - - 3b1 FPS Plan 9 - AmigaOS GENIX PowerUX - ConvexOS Greenhills RISC/os - CX/UX ISC Stellar - DC/OSx MachTen 68k SVR2 - DDE SMES MiNT TI1500 - DomainOS MPC TitanOS - DOS EMX NEWS-OS UNICOS/mk - Dynix Opus Unisys Dynix - EP/IX Unixware - ESIX - -The following platforms are planned to be supported in the standard -source code distribution of the Perl release 5.006 but are not -supported in the Perl release 5.005_03: - - BS2000 - Netware - Rhapsody - VM/ESA - -The following platforms have their own source code distributions and -binaries available via F. - - Perl release - - AS/400 5.003 - MacOS 5.004 - Netware 5.003_07 - Tandem Guardian 5.004 - -The following platforms have only binaries available via -F. - - Perl release - - Acorn RISCOS 5.005_02 - AOS 5.002 - LynxOS 5.004_02 +Perl is available for most operating systems, including virtually +all Unix-like platforms. See L +for a listing. =head1 ENVIRONMENT @@ -323,12 +231,12 @@ See L. =head1 AUTHOR -Larry Wall >, with the help of oodles of other folks. +Larry Wall , with the help of oodles of other folks. If your Perl success stories and testimonials may be of help to others who wish to advocate the use of Perl in their applications, or if you wish to simply express your gratitude to Larry and the -Perl developers, please write to >. +Perl developers, please write to perl-thanks@perl.org . =head1 FILES @@ -337,12 +245,15 @@ Perl developers, please write to >. =head1 SEE ALSO a2p awk to perl translator - s2p sed to perl translator + http://www.perl.com/ the Perl Home Page + http://www.perl.com/CPAN the Comprehensive Perl Archive + =head1 DIAGNOSTICS -The B<-w> switch produces some lovely diagnostics. +The C pragma (and the B<-w> switch) produces some +lovely diagnostics. See L for explanations of all Perl's diagnostics. The C pragma automatically turns Perl's normally terse warnings @@ -350,7 +261,7 @@ and errors into these longer forms. Compilation errors will tell you the line number of the error, with an indication of the next token or token type that was to be examined. -(In the case of a script passed to Perl via B<-e> switches, each +(In a script passed to Perl via B<-e> switches, each B<-e> is counted as one line.) Setuid scripts have additional constraints that can produce error @@ -379,10 +290,10 @@ so they are limited to a maximum of 65535 (higher numbers usually being affected by wraparound). You may mail your bug reports (be sure to include full configuration -information as output by the myconfig program in the perl source tree, -or by C) to >. -If you've succeeded in compiling perl, the perlbug script in the utils/ -subdirectory can be used to help mail in a bug report. +information as output by the myconfig program in the perl source +tree, or by C) to perlbug@perl.com . If you've succeeded +in compiling perl, the B script in the F subdirectory +can be used to help mail in a bug report. Perl actually stands for Pathologically Eclectic Rubbish Lister, but don't tell anyone I said that.