X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=pod%2Fperl.pod;h=3036f35b2197e7dd352c8d59dca229bfbfb5d1ed;hb=84850974f570c6c594cc0df54611ffc5f0b26130;hp=dcab07a37b2442b6cb950219e88073df08d95fa8;hpb=774d564bb7dd1ed64ca0d7e534aa67e93f991f02;p=p5sagit%2Fp5-mst-13.2.git diff --git a/pod/perl.pod b/pod/perl.pod index dcab07a..3036f35 100644 --- a/pod/perl.pod +++ b/pod/perl.pod @@ -20,6 +20,7 @@ of sections: perl Perl overview (this section) perldelta Perl changes since previous version + perlfaq Perl frequently asked questions perldata Perl data structures perlsyn Perl syntax @@ -29,11 +30,12 @@ of sections: perlfunc Perl builtin functions perlvar Perl predefined variables perlsub Perl subroutines - perlmod Perl modules + perlmod Perl modules: how they work + perlmodlib Perl modules: how to write and use perlform Perl formats perllocale Perl locale support - perlref Perl references + perlref Perl references perldsc Perl data structures intro perllol Perl data structures: lists of lists perltoot Perl OO tutorial @@ -51,27 +53,38 @@ of sections: perlpod Perl plain old documentation perlbook Perl book information - perlembed Perl how to embed perl in your C or C++ app + perlembed Perl ways to embed perl in your C or C++ application perlapio Perl internal IO abstraction interface perlxs Perl XS application programming interface perlxstut Perl XS tutorial - perlguts Perl internal functions for those doing extensions + perlguts Perl internal functions for those doing extensions perlcall Perl calling conventions from C (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.) -Additional documentation for Perl modules is available in the -F directory. Some of this is distributed standard with -Perl, but you'll also find third-party modules there. You should be able -to view this with your man(1) program by including the proper directories -in the appropriate start-up files. To find out where these are, type: +By default, all of the above manpages are installed in the +F directory. + +Extensive additional documentation for Perl modules is available. The +default configuration for perl will place this additional documentation +in the F directory (or else in the F +subdirectory of the Perl library directory). Some of this additional +documentation is distributed standard with Perl, but you'll also find +documentation for third-party modules there. + +You should be able to view Perl's documentation with your man(1) +program by including the proper directories in the appropriate start-up +files, or in the MANPATH environment variable. To find out where the +configuration has installed the manpages, type: perl -V:man.dir -If the directories were F and F, -you would need to add only F to your MANPATH. If -they are different, you'll have to add both stems. +If the directories have a common stem, such as F +and F, you need only to add that stem +(F) to your man(1) configuration files or your MANPATH +environment variable. If they do not share a stem, you'll have to add +both stems. If that doesn't work for some reason, you can still use the supplied F script to view module information. You might @@ -90,26 +103,28 @@ system management tasks. The language is intended to be practical (easy to use, efficient, complete) rather than beautiful (tiny, elegant, minimal). -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 +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 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 hash tables used by associative arrays -grow as necessary to prevent degraded performance. Perl uses -sophisticated pattern matching techniques to scan large amounts of data -very quickly. Although optimized for scanning text, Perl can also -deal with binary data, and can make dbm files look like associative -arrays. Setuid Perl scripts are safer than -C programs through a dataflow tracing mechanism which prevents many -stupid security holes. If you have a problem that would ordinarily use -B or B or B, but it exceeds their capabilities or must -run a little faster, and you don't want to write the silly thing in C, -then Perl may be for you. There are also translators to turn your -B and B scripts into Perl scripts. +Perl can slurp in your whole file as a single string. Recursion is of +unlimited depth. And the tables used by hashes (previously called +"associative arrays") grow as necessary to prevent degraded +performance. Perl uses sophisticated pattern matching techniques to +scan large amounts of data very 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 +security holes. + +If you have a problem that would ordinarily use B or B or +B, but it exceeds their capabilities or must run a little faster, +and you don't want to write the silly thing in C, then Perl may be for +you. There are also translators to turn your B and B +scripts into Perl scripts. But wait, there's more... @@ -139,7 +154,7 @@ will continue to work unchanged. 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 +to better privacy for "programming in the large". Anonymous subroutines exhibit deep binding of lexical variables (closures). =item * Arbitrarily nested data structures @@ -197,7 +212,7 @@ semantics for undefined subroutine calls. It's not for just autoloading. =item * Regular expression enhancements -You can now specify non-greedy quantifiers. You can now do grouping +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 @@ -205,84 +220,27 @@ all old regular expressions. =item * Innumerable Unbundled Modules -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. +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 * Compilability While not yet in full production mode, a working perl-to-C compiler -does exist. It can generate portable bytecode, simple C, or +does exist. It can generate portable byte code, simple C, or optimized C code. =back -Ok, that's I enough hype. +Okay, that's I enough hype. =head1 ENVIRONMENT -=over 12 - -=item HOME - -Used if chdir has no argument. - -=item LOGDIR - -Used if chdir has no argument and HOME is not set. - -=item PATH - -Used in executing subprocesses, and in finding the script if B<-S> is -used. - -=item PERL5LIB - -A colon-separated list of directories in which to look for Perl library -files before looking in the standard library and the current -directory. If PERL5LIB is not defined, PERLLIB is used. When running -taint checks (because the script was running setuid or setgid, or the -B<-T> switch was used), neither variable is used. The script should -instead say - - use lib "/my/directory"; - -=item PERL5DB - -The command used to get the debugger code. If unset, uses - - BEGIN { require 'perl5db.pl' } - -=item PERL_DESTRUCT_LEVEL - -Relevant only if your perl executable was built with B<-DDEBUGGING>, -this controls the behavior of global destruction of objects and other -references. - -=item PERLLIB - -A colon-separated list of directories in which to look for Perl library -files before looking in the standard library and the current -directory. If PERL5LIB is defined, PERLLIB is not used. - -=back - -Perl also has environment variables that control how Perl handles data -specific to particular natural languages. See L. - -Apart from these, Perl uses no other environment variables, except -to make them available to the script being executed, and to child -processes. However, scripts running setuid would do well to execute -the following lines before doing anything else, just to keep people -honest: - - $ENV{'PATH'} = '/bin:/usr/bin'; # or whatever you need - $ENV{'SHELL'} = '/bin/sh' if defined $ENV{'SHELL'}; - $ENV{'IFS'} = '' if defined $ENV{'IFS'}; +See L. =head1 AUTHOR -Larry Wall EFE, with the help of oodles of other folks. +Larry Wall >, with the help of oodles of other folks. =head1 FILES @@ -317,8 +275,8 @@ switch? The B<-w> switch is not mandatory. Perl is at the mercy of your machine's definitions of various -operations such as type casting, atof(), and sprintf(). The latter -can even trigger a core dump when passed ludicrous input values. +operations such as type casting, atof(), and floating-point +output with sprintf(). If your stdio requires a seek or eof between reads and writes on a particular stream, so does Perl. (This doesn't apply to sysread() @@ -330,10 +288,9 @@ given variable name may not be longer than 255 characters, and no component of your PATH may be longer than 255 if you use B<-S>. A regular expression may not compile to more than 32767 bytes internally. -See the perl bugs database at F. 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 -F. +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.