Re: Exceptions in IPC::Open2

[p5sagit/p5-mst-13.2.git] / pod / perlfaq2.pod

=head1 NAME

perlfaq2 - Obtaining and Learning about Perl ($Revision: 1.16 $, $Date: 1997/04/23 18:04:09 $)

=head1 DESCRIPTION

This section of the FAQ answers questions about where to find
source and documentation for Perl, support and training, and
related matters.

=head2 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.perl.com/CPAN/src/latest.tar.gz, which is a
gzipped archive in POSIX tar format.  This source builds with no
porting whatsoever on most Unix systems (Perl's native environment),
as well as Windows NT, Plan 9, VMS, QNX, OS/2, and the Amiga.

Binary distributions for various platforms can be found
http://www.perl.com/CPAN/ports/ directory.  Some of these ports (especially
the ones that are not part of the standard sources) may behave differently
than what is documented in the standard source documentation.  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).

A useful FAQ for Win32 Perl users is:
http://www.endcontsw.com/people/evangelo/Perl_for_Win32_FAQ.html
[This FAQ is seriously outdated as of Jan 1998--it is only relevant to
the perl that ActiveState distributes, especially where it describes
various inadequacies and differences with the standard perl extension
build support.]

=head2 How can I get a binary version of Perl?

If you don't have a C compiler because for whatever reasons your
vendor 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.  CPAN only has binaries for systems that are terribly hard to
get free compilers for, not for Unix systems.

Your first stop should be http://www.perl.com/CPAN/ports to see what
information is already available.  A simple installation guide for
MS-DOS is available at http://www.cs.ruu.nl/~piet/perl5dos.html , and
similarly for Windows 3.1 at http://www.cs.ruu.nl/~piet/perlwin3.html
.

=head2 I don't have a C compiler on my system.  How can I compile perl?

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.

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.

=head2 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 C<make install>.  Most other
approaches are doomed to failure.

One simple way to check that things are in the right place is to print out
the hard-coded @INC which perl is looking for.

	perl -e 'print join("\n",@INC)'

If this command lists any paths which don't exist on your system, then you
may need to move the appropriate libraries to these locations, or create
symlinks, aliases, or shortcuts appropriately.

You might also want to check out L<perlfaq8/"How do I keep my own
module/library directory?">.

=head2 I grabbed the sources and tried to compile but gdbm/dynamic loading/malloc/linking/... failed.  How do I make it work?

Read the F<INSTALL> file, which is part of the source distribution.
It describes in detail how to cope with most idiosyncracies that the
Configure script can't work around for any given system or
architecture.

=head2 What modules and extensions are available for Perl?  What is CPAN?  What does CPAN/src/... mean?

CPAN stands for Comprehensive Perl Archive Network, a huge archive
replicated on dozens of machines all over the world.  CPAN 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 CGI scripts.  The master machine for CPAN is
ftp://ftp.funet.fi/pub/languages/perl/CPAN/, but you can use the
address http://www.perl.com/CPAN/CPAN.html to fetch a copy from a
"site near you".  See http://www.perl.com/CPAN (without a slash at the
end) for how this process works.

CPAN/path/... is a naming convention for files available on CPAN
sites.  CPAN indicates the base directory of a CPAN 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 CPAN site, the file CPAN/misc/japh file is downloadable as
ftp://ftp.funet.fi/pub/languages/perl/CPAN/misc/japh .

Considering that there are hundreds of 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.

=head2 Is there an ISO or ANSI certified version of Perl?

Certainly not.  Larry expects that he'll be certified before Perl is.

=head2 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 C<man perl> if you're on a
system resembling Unix.  This will lead you to other important man
pages.  If you're not on a Unix system, access to the documentation
will be different; for example, it might be only in HTML format.  But
all proper perl installations have fully-accessible documentation.

You might also try C<perldoc perl> 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.

If all else fails, consult the CPAN/doc directory, which contains the
complete documentation in various formats, including native pod,
troff, html, and plain text.  There's also a web page at
http://www.perl.com/perl/info/documentation.html that might help.

It's also worth noting that there's a PDF version of the complete
documentation for perl available in the CPAN/authors/id/BMIDD
directory.

Many good books have been written about Perl -- see the section below
for more details.

=head2 What are the Perl newsgroups on USENET?  Where do I post questions?

The now defunct comp.lang.perl newsgroup has been superseded by the
following groups:

    comp.lang.perl.announce 		Moderated announcement group
    comp.lang.perl.misc     		Very busy group about Perl in general
    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.

There is also USENET gateway to the mailing list used by the crack
Perl development team (perl5-porters) at
news://genetics.upenn.edu/perl.porters-gw/ .

=head2 Where should I post source code?

You should post source code to whichever group is most appropriate,
but feel free to cross-post to comp.lang.perl.misc.  If you want to
cross-post to alt.sources, please make sure it follows their posting
standards, including setting the Followup-To header line to NOT
include alt.sources; see their FAQ for details.

=head2 Perl Books

A number of books on Perl and/or CGI programming are available.  A few of
these are good, some are ok, but many aren't worth your money.  Tom
Christiansen maintains a list of these books, some with extensive
reviews, at http://www.perl.com/perl/critiques/index.html.

The incontestably definitive reference book on Perl, written by the
creator of Perl and his apostles, is now in its second edition and
fourth printing.

    Programming Perl (the "Camel Book"):
	Authors: Larry Wall, Tom Christiansen, and Randal Schwartz
        ISBN 1-56592-149-6      (English)
        ISBN 4-89052-384-7      (Japanese)
	(French and German translations in progress)

Note that O'Reilly books are color-coded: turquoise (some would call
it teal) covers indicate perl5 coverage, while magenta (some would
call it pink) covers indicate perl4 only.  Check the cover color
before you buy!

What follows is a list of the books that the FAQ authors found personally
useful.  Your mileage may (but, we hope, probably won't) vary.

If you're already a hard-core systems programmer, then the Camel Book
just might suffice for you to learn Perl from.  But if you're not,
check out the "Llama Book".  It currently doesn't cover perl5, but the
2nd edition is nearly done and should be out by summer 97:

    Learning Perl (the Llama Book):
	Author: Randal Schwartz, with intro by Larry Wall
        ISBN 1-56592-042-2      (English)
        ISBN 4-89502-678-1      (Japanese)
        ISBN 2-84177-005-2      (French)
        ISBN 3-930673-08-8      (German)

Another stand-out book in the turquoise O'Reilly Perl line is the "Hip
Owls" book.  It covers regular expressions inside and out, with quite a
bit devoted exclusively to Perl:

    Mastering Regular Expressions (the Cute Owls Book):
	Author: Jeffrey Friedl
	ISBN 1-56592-257-3

You can order any of these books from O'Reilly & Associates,
1-800-998-9938.  Local/overseas is 1-707-829-0515.  If you can locate
an O'Reilly order form, you can also fax to 1-707-829-0104.  See
http://www.ora.com/ on the Web.

Recommended Perl books that are not from O'Reilly are the following:

   Cross-Platform Perl, (for Unix and Windows NT)
       Author: Eric F. Johnson
       ISBN: 1-55851-483-X

   How to Set up and Maintain a World Wide Web Site, (2nd edition)
	Author: Lincoln Stein, M.D., Ph.D.
	ISBN: 0-201-63462-7

   CGI Programming in C & Perl,
	Author: Thomas Boutell
	ISBN: 0-201-42219-0

Note that some of these address specific application areas (e.g. the
Web) and are not general-purpose programming books.

=head2 Perl in Magazines

The Perl Journal is the first and only magazine dedicated to Perl.
It is published (on paper, not online) quarterly by Jon Orwant
(orwant@tpj.com), editor.  Subscription information is at http://tpj.com
or via email to subscriptions@tpj.com.

Beyond this, two other magazines that frequently carry high-quality
articles on Perl are Web Techniques (see
http://www.webtechniques.com/) and Unix Review
(http://www.unixreview.com/).  Randal Schwartz's Web Technique's
columns are available on the web at
http://www.stonehenge.com/merlyn/WebTechniques/ .

=head2 Perl on the Net: FTP and WWW Access

To get the best (and possibly cheapest) performance, pick a site from
the list below and use it to grab the complete list of mirror sites.
From there you can find the quickest site for you.  Remember, the
following list is I<not> the complete list of CPAN mirrors.

  http://www.perl.com/CPAN	(redirects to another mirror)
  http://www.perl.org/CPAN
  ftp://ftp.funet.fi/pub/languages/perl/CPAN/
  http://www.cs.ruu.nl/pub/PERL/CPAN/
  ftp://ftp.cs.colorado.edu/pub/perl/CPAN/

http:/www.oasis.leo.org/perl/ has, amongst other things, source to
versions 1 through 5 of Perl.

=head2 What mailing lists are there for perl?

Most of the major modules (tk, CGI, libwww-perl) have their own
mailing lists.  Consult the documentation that came with the module for
subscription information.  The following are a list of mailing lists
related to perl itself.

If you subscribe to a mailing list, it behooves you to know how to
unsubscribe from it.  Strident pleas to the list itself to get you off
will not be favorably received.

=over 4

=item MacPerl

There is a mailing list for discussing Macintosh Perl.  Contact
"mac-perl-request@iis.ee.ethz.ch".

Also see Matthias Neeracher's (the creator and maintainer of MacPerl)
webpage at http://www.iis.ee.ethz.ch/~neeri/macintosh/perl.html for
many links to interesting MacPerl sites, and the applications/MPW
tools, precompiled.

=item Perl5-Porters

The core development team have a mailing list for discussing fixes and
changes to the language.  Send mail to
"perl5-porters-request@perl.org" with help in the body of the message
for information on subscribing.

=item NTPerl

This list is used to discuss issues involving Win32 Perl 5 (Windows NT
and Win95). Subscribe by emailing ListManager@ActiveWare.com with the
message body:

    subscribe Perl-Win32-Users

The list software, also written in perl, will automatically determine
your address, and subscribe you automatically.  To unsubscribe, email
the following in the message body to the same address like so:

    unsubscribe Perl-Win32-Users

You can also check http://www.activeware.com/ and select "Mailing Lists"
to join or leave this list.

=item Perl-Packrats

Discussion related to archiving of perl materials, particularly the
Comprehensive Perl Archive Network (CPAN). Subscribe by emailing
majordomo@cis.ufl.edu:

    subscribe perl-packrats

The list software, also written in perl, will automatically determine
your address, and subscribe you automatically.  To unsubscribe, simple
prepend the same command with an "un", and mail to the same address
like so:

    unsubscribe perl-packrats

=back

=head2 Archives of comp.lang.perl.misc

Have you tried Deja News or Alta Vista?

ftp.cis.ufl.edu:/pub/perl/comp.lang.perl.*/monthly has an almost
complete collection dating back to 12/89 (missing 08/91 through
12/93).  They are kept as one large file for each month.

You'll probably want more a sophisticated query and retrieval mechanism
than a file listing, preferably one that allows you to retrieve
articles using a fast-access indices, keyed on at least author, date,
subject, thread (as in "trn") and probably keywords.  The best
solution the FAQ authors know of is the MH pick command, but it is
very slow to select on 18000 articles.

If you have, or know where can be found, the missing sections, please
let perlfaq-suggestions@perl.com know.

=head2 Perl Training

While some large training companies offer their own courses on Perl,
you may prefer to contact individuals near and dear to the heart of
Perl development.  Two well-known members of the Perl development team
who offer such things are Tom Christiansen <perl-classes@perl.com>
and Randal Schwartz <perl-training-info@stonehenge.com>, plus their
respective minions, who offer a variety of professional tutorials
and seminars on Perl.  These courses include large public seminars,
private corporate training, and fly-ins to Colorado and Oregon.
See http://www.perl.com/perl/info/training.html for more details.

=head2 Where can I buy a commercial version of Perl?

In a sense, Perl already I<is> commercial software: It has a licence
that you can grab and carefully read to your manager. It is
distributed in releases and comes in well-defined packages. There is a
very large user community and an extensive literature.  The
comp.lang.perl.* newsgroups and several of the mailing lists provide
free answers to your questions in near real-time.  Perl has
traditionally been supported by Larry, dozens of software designers
and developers, and thousands of programmers, all working for free
to create a useful thing to make life better for everyone.

However, these answers may not suffice for managers who require a
purchase order from a company whom they can sue should anything go
wrong.  Or maybe they need very serious hand-holding and contractual
obligations.  Shrink-wrapped CDs with perl on them are available from
several sources if that will help.

Or you can purchase a real support contract.  Although Cygnus historically
provided this service, they no longer sell support contracts for Perl.
Instead, the Paul Ingram Group will be taking up the slack through The
Perl Clinic.  The following is a commercial from them:

"Do you need professional support for Perl and/or Oraperl?  Do you need
a support contract with defined levels of service?  Do you want to pay
only for what you need?

"The Paul Ingram Group has provided quality software development and
support services to some of the world's largest corporations for ten
years.  We are now offering the same quality support services for Perl
at The Perl Clinic.  This service is led by Tim Bunce, an active perl
porter since 1994 and well known as the author and maintainer of the
DBI, DBD::Oracle, and Oraperl modules and author/co-maintainer of The
Perl 5 Module List.  We also offer Oracle users support for Perl5
Oraperl and related modules (which Oracle is planning to ship as part
of Oracle Web Server 3).  20% of the profit from our Perl support work
will be donated to The Perl Institute."

For more information, contact the The Perl Clinic:

    Tel:    +44 1483 424424
    Fax:    +44 1483 419419
    Web:    http://www.perl.co.uk/
    Email:  perl-support-info@perl.co.uk or Tim.Bunce@ig.co.uk

=head2 Where do I send bug reports?

If you are reporting a bug in the perl interpreter or the modules
shipped with perl, use the perlbug program in the perl distribution or
email your report to perlbug@perl.com.

If you are posting a bug with a non-standard port (see the answer to
"What platforms is Perl available for?"), a binary distribution, or a
non-standard module (such as Tk, CGI, etc), then please see the
documentation that came with it to determine the correct place to post
bugs.

Read the perlbug man page (perl5.004 or later) for more information.

=head2 What is perl.com?  perl.org?  The Perl Institute?

perl.org is the official vehicle for The Perl Institute.  The motto of
TPI is "helping people help Perl help people" (or something like
that).  It's a non-profit organization supporting development,
documentation, and dissemination of perl.  Current directors of TPI
include Larry Wall, Tom Christiansen, and Randal Schwartz, whom you
may have heard of somewhere else around here.

The perl.com domain is Tom Christiansen's domain.  He created it as a
public service long before perl.org came about.  It's the original PBS
of the Perl world, a clearinghouse for information about all things
Perlian, accepting no paid advertisements, glossy gifs, or (gasp!)
java applets on its pages.

=head2 How do I learn about object-oriented Perl programming?

L<perltoot> (distributed with 5.004 or later) is a good place to start.
Also, L<perlobj>, L<perlref>, and L<perlmod> are useful references,
while L<perlbot> has some excellent tips and tricks.

=head1 AUTHOR AND COPYRIGHT

Copyright (c) 1997 Tom Christiansen and Nathan Torkington.
All rights reserved.  See L<perlfaq> for distribution information.