perlfaq2.1

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.\" ========================================================================
.\"
.IX Title "PERLFAQ2 1"
.TH PERLFAQ2 1 "2007-12-18" "perl v5.10.0" "Perl Programmers Reference Guide"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
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.SH "NAME"
perlfaq2 \- Obtaining and Learning about Perl ($Revision: 10144 $)
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
This section of the \s-1FAQ\s0 answers questions about where to find
source and documentation for Perl, support, and
related matters.
.Sh "What machines support perl?  Where do I get it?"
.IX Subsection "What machines support perl?  Where do I get it?"
The standard release of perl (the one maintained by the perl
development team) is distributed only in source code form.  You
can find this at http://www.cpan.org/src/latest.tar.gz , which
is in a standard Internet format (a gzipped archive in \s-1POSIX\s0 tar format).
.PP
Perl builds and runs on a bewildering number of platforms.  Virtually
all known and current Unix derivatives are supported (perl's native
platform), as are other systems like \s-1VMS\s0, \s-1DOS\s0, \s-1OS/2\s0, Windows,
\&\s-1QNX\s0, BeOS, \s-1OS\s0 X, MPE/iX and the Amiga.
.PP
Binary distributions for some proprietary platforms, including
Apple systems, can be found http://www.cpan.org/ports/ directory.
Because these are not part of the standard distribution, they may
and in fact do differ from the base perl port in a variety of ways.
You'll have to check their respective release notes to see just
what the differences are.  These differences can be either positive
(e.g. extensions for the features of the particular platform that
are not supported in the source release of perl) or negative (e.g.
might be based upon a less current source release of perl).
.Sh "How can I get a binary version of perl?"
.IX Subsection "How can I get a binary version of perl?"
For Windows, ActiveState provides a pre-built Perl for free:
.PP
.Vb 1
\&        http://www.activestate.com/
.Ve
.PP
Sunfreeware.com provides binaries for many utilities, including
Perl, for Solaris on both Intel and \s-1SPARC\s0 hardware:
.PP
.Vb 1
\&        http://www.sunfreeware.com/
.Ve
.PP
If you don't have a C compiler because your vendor for whatever
reasons did not include one with your system, the best thing to do is
grab a binary version of gcc from the net and use that to compile perl
with.  \s-1CPAN\s0 only has binaries for systems that are terribly hard to
get free compilers for, not for Unix systems.
.PP
Some URLs that might help you are:
.PP
.Vb 2
\&        http://www.cpan.org/ports/
\&        http://www.perl.com/pub/language/info/software.html
.Ve
.PP
Someone looking for a perl for Win16 might look to Laszlo Molnar's
djgpp port in http://www.cpan.org/ports/#msdos , which comes with
clear installation instructions.
.Sh "I don't have a C compiler. How can I build my own Perl interpreter?"
.IX Subsection "I don't have a C compiler. How can I build my own Perl interpreter?"
Since you don't have a C compiler, you're doomed and your vendor
should be sacrificed to the Sun gods.  But that doesn't help you.
.PP
What you need to do is get a binary version of gcc for your system
first.  Consult the Usenet FAQs for your operating system for
information on where to get such a binary version.
.PP
You might look around the net for a pre-built binary of Perl (or a 
C compiler!) that meets your needs, though:
.PP
For Windows, Vanilla Perl ( http://vanillaperl.com/ ) and Strawberry Perl
( http://strawberryperl.com/ ) come with a 
bundled C compiler. ActivePerl is a pre-compiled version of Perl
ready-to-use.
.PP
For Sun systems, SunFreeware.com provides binaries of most popular 
applications, including compilers and Perl.
.Sh "I copied the perl binary from one machine to another, but scripts don't work."
.IX Subsection "I copied the perl binary from one machine to another, but scripts don't work."
That's probably because you forgot libraries, or library paths differ.
You really should build the whole distribution on the machine it will
eventually live on, and then type \f(CW\*(C`make install\*(C'\fR.  Most other
approaches are doomed to failure.
.PP
One simple way to check that things are in the right place is to print out
the hard-coded \f(CW@INC\fR that perl looks through for libraries:
.PP
.Vb 1
\&    % perl \-le \*(Aqprint for @INC\*(Aq
.Ve
.PP
If this command lists any paths that don't exist on your system, then you
may need to move the appropriate libraries to these locations, or create
symbolic links, aliases, or shortcuts appropriately.  \f(CW@INC\fR is also printed as
part of the output of
.PP
.Vb 1
\&    % perl \-V
.Ve
.PP
You might also want to check out
\&\*(L"How do I keep my own module/library directory?\*(R" in perlfaq8.
.Sh "I grabbed the sources and tried to compile but gdbm/dynamic loading/malloc/linking/... failed.  How do I make it work?"
.IX Subsection "I grabbed the sources and tried to compile but gdbm/dynamic loading/malloc/linking/... failed.  How do I make it work?"
Read the \fI\s-1INSTALL\s0\fR file, which is part of the source distribution.
It describes in detail how to cope with most idiosyncrasies that the
Configure script can't work around for any given system or
architecture.
.Sh "What modules and extensions are available for Perl?  What is \s-1CPAN\s0?  What does CPAN/src/... mean?"
.IX Subsection "What modules and extensions are available for Perl?  What is CPAN?  What does CPAN/src/... mean?"
\&\s-1CPAN\s0 stands for Comprehensive Perl Archive Network, a multi-gigabyte
archive replicated on hundreds of machines all over the world. \s-1CPAN\s0
contains source code, non-native ports, documentation, scripts, and
many third-party modules and extensions, designed for everything from
commercial database interfaces to keyboard/screen control to web
walking and \s-1CGI\s0 scripts. The master web site for \s-1CPAN\s0 is
http://www.cpan.org/ and there is the \s-1CPAN\s0 Multiplexer at
http://www.cpan.org/CPAN.html which will choose a mirror near you via
\&\s-1DNS\s0.  See http://www.perl.com/CPAN (without a slash at the end) for
how this process works. Also, http://mirror.cpan.org/ has a nice
interface to the http://www.cpan.org/MIRRORED.BY mirror directory.
.PP
See the \s-1CPAN\s0 \s-1FAQ\s0 at http://www.cpan.org/misc/cpan\-faq.html for answers
to the most frequently asked questions about \s-1CPAN\s0 including how to
become a mirror.
.PP
CPAN/path/... is a naming convention for files available on \s-1CPAN\s0
sites.  \s-1CPAN\s0 indicates the base directory of a \s-1CPAN\s0 mirror, and the
rest of the path is the path from that directory to the file. For
instance, if you're using ftp://ftp.funet.fi/pub/languages/perl/CPAN
as your \s-1CPAN\s0 site, the file CPAN/misc/japh is downloadable as
ftp://ftp.funet.fi/pub/languages/perl/CPAN/misc/japh .
.PP
Considering that, as of 2006, there are over ten thousand existing
modules in the archive, one probably exists to do nearly anything you
can think of. Current categories under CPAN/modules/by\-category/
include Perl core modules; development support; operating system
interfaces; networking, devices, and interprocess communication; data
type utilities; database interfaces; user interfaces; interfaces to
other languages; filenames, file systems, and file locking;
internationalization and locale; world wide web support; server and
daemon utilities; archiving and compression; image manipulation; mail
and news; control flow utilities; filehandle and I/O; Microsoft
Windows modules; and miscellaneous modules.
.PP
See http://www.cpan.org/modules/00modlist.long.html or
http://search.cpan.org/ for a more complete list of modules by
category.
.PP
\&\s-1CPAN\s0 is a free service and is not affiliated with O'Reilly Media.
.Sh "Is there an \s-1ISO\s0 or \s-1ANSI\s0 certified version of Perl?"
.IX Subsection "Is there an ISO or ANSI certified version of Perl?"
Certainly not.  Larry expects that he'll be certified before Perl is.
.Sh "Where can I get information on Perl?"
.IX Subsection "Where can I get information on Perl?"
The complete Perl documentation is available with the Perl distribution.
If you have Perl installed locally, you probably have the documentation
installed as well: type \f(CW\*(C`man perl\*(C'\fR if you're on a system resembling Unix.
This will lead you to other important man pages, including how to set your
\&\f(CW$MANPATH\fR.  If you're not on a Unix system, access to the documentation
will be different; for example, documentation might only be in \s-1HTML\s0 format.  All
proper perl installations have fully-accessible documentation.
.PP
You might also try \f(CW\*(C`perldoc perl\*(C'\fR in case your system doesn't
have a proper man command, or it's been misinstalled.  If that doesn't
work, try looking in /usr/local/lib/perl5/pod for documentation.
.PP
If all else fails, consult http://perldoc.perl.org/ which has the
complete documentation in \s-1HTML\s0 and \s-1PDF\s0 format.
.PP
Many good books have been written about Perl\*(--see the section later in
perlfaq2 for more details.
.PP
Tutorial documents are included in current or upcoming Perl releases
include perltoot for objects or perlboot for a beginner's
approach to objects, perlopentut for file opening semantics,
perlreftut for managing references, perlretut for regular
expressions, perlthrtut for threads, perldebtut for debugging,
and perlxstut for linking C and Perl together.  There may be more
by the time you read this.  These URLs might also be useful:
.PP
.Vb 2
\&    http://perldoc.perl.org/
\&    http://bookmarks.cpan.org/search.cgi?cat=Training%2FTutorials
.Ve
.Sh "What are the Perl newsgroups on Usenet?  Where do I post questions?"
.IX Subsection "What are the Perl newsgroups on Usenet?  Where do I post questions?"
Several groups devoted to the Perl language are on Usenet:
.PP
.Vb 5
\&    comp.lang.perl.announce             Moderated announcement group
\&    comp.lang.perl.misc                 High traffic general Perl discussion
\&    comp.lang.perl.moderated        Moderated discussion group
\&    comp.lang.perl.modules              Use and development of Perl modules
\&    comp.lang.perl.tk                   Using Tk (and X) from Perl
\&
\&    comp.infosystems.www.authoring.cgi  Writing CGI scripts for the Web.
.Ve
.PP
Some years ago, comp.lang.perl was divided into those groups, and
comp.lang.perl itself officially removed.  While that group may still
be found on some news servers, it is unwise to use it, because
postings there will not appear on news servers which honour the
official list of group names.  Use comp.lang.perl.misc for topics
which do not have a more-appropriate specific group.
.PP
There is also a Usenet gateway to Perl mailing lists sponsored by
perl.org at nntp://nntp.perl.org , a web interface to the same lists