=head1 NAME
-perlfaq3 - Programming Tools ($Revision: 3606 $)
+perlfaq3 - Programming Tools ($Revision: 10127 $)
=head1 DESCRIPTION
Before you do anything else, you can help yourself by ensuring that
you let Perl tell you about problem areas in your code. By turning
-on warnings and strictures, you can head off many problems before
+on warnings and strictures, you can head off many problems before
they get too big. You can find out more about these in L<strict>
and L<warnings>.
#!/usr/bin/perl
use strict;
use warnings;
-
+
Beyond that, the simplest debugger is the C<print> function. Use it
to look at values as you run your program:
The C<Data::Dumper> module can pretty-print Perl data structures:
- use Data::Dumper( Dump );
- print STDERR "The hash is " . Dump( \%hash ) . "\n";
-
+ use Data::Dumper qw( Dumper );
+ print STDERR "The hash is " . Dumper( \%hash ) . "\n";
+
Perl comes with an interactive debugger, which you can start with the
C<-d> switch. It's fully explained in L<perldebug>.
If you'd like a graphical user interface and you have Tk, you can use
C<ptkdb>. It's on CPAN and available for free.
-If you need something much more sophisicated and controllable, Leon
+If you need something much more sophisticated and controllable, Leon
Brocard's Devel::ebug (which you can call with the -D switch as -Debug)
gives you the programmatic hooks into everything you need to write your
own (without too much pain and suffering).
Put that in your F<.exrc> file (replacing the caret characters
with control characters) and away you go. In insert mode, ^T is
-for indenting, ^D is for undenting, and ^O is for blockdenting--
-as it were. A more complete example, with comments, can be found at
+for indenting, ^D is for undenting, and ^O is for blockdenting--as
+it were. A more complete example, with comments, can be found at
http://www.cpan.org/authors/id/TOMC/scripts/toms.exrc.gz
The a2ps http://www-inf.enst.fr/%7Edemaille/a2ps/black+white.ps.gz does
lots of things related to generating nicely printed output of
-documents, as does enscript at http://people.ssh.fi/mtr/genscript/ .
+documents.
=head2 Is there a ctags for Perl?
(contributed by brian d foy)
+Ctags uses an index to quickly find things in source code, and many
+popular editors support ctags for several different languages,
+including Perl.
+
Exuberent ctags supports Perl: http://ctags.sourceforge.net/
You might also try pltags: http://www.mscha.com/pltags.zip
environments) comes with a simple editor. Popular external editors are
BBEdit ( http://www.bbedit.com/ ) or Alpha (
http://www.his.com/~jguyer/Alpha/Alpha8.html ). MacOS X users can use
-Unix editors as well. Neil Bowers (the man behind Geekcruises) has a
-list of Mac editors that can handle Perl (
-http://www.neilbowers.org/macperleditors.html ).
+Unix editors as well.
=over 4
There is also a toyedit Text widget based editor written in Perl
that is distributed with the Tk module on CPAN. The ptkdb
-( http://world.std.com/~aep/ptkdb/ ) is a Perl/tk based debugger that
+( http://ptkdb.sourceforge.net/ ) is a Perl/tk based debugger that
acts as a development environment of sorts. Perl Composer
( http://perlcomposer.sourceforge.net/ ) is an IDE for Perl/Tk
GUI creation.
=item Zsh
-ftp://ftp.blarg.net/users/amol/zsh/ , see also http://www.zsh.org/
+http://www.zsh.org/
=back
this program repeats a command and updates the screen as needed, rendering
B<rep ps axu> similar to B<top>.
-=head2 How can I use X or Tk with Perl?
+=head2 How can I write a GUI (X, Tk, Gtk, etc.) in Perl?
+X<GUI> X<Tk> X<Wx> X<WxWidgets> X<Gtk> X<Gtk2> X<CamelBones> X<Qt>
+
+(contributed by Ben Morrow)
+
+There are a number of modules which let you write GUIs in Perl. Most
+GUI toolkits have a perl interface: an incomplete list follows.
+
+=over 4
+
+=item Tk
+
+This works under Unix and Windows, and the current version doesn't
+look half as bad under Windows as it used to. Some of the gui elements
+still don't 'feel' quite right, though. The interface is very natural
+and 'perlish', making it easy to use in small scripts that just need a
+simple gui. It hasn't been updated in a while.
+
+=item Wx
+
+This is a Perl binding for the cross-platform wxWidgets toolkit
+L<http://www.wxwidgets.org>. It works under Unix, Win32 and Mac OS X,
+using native widgets (Gtk under Unix). The interface follows the C++
+interface closely, but the documentation is a little sparse for someone
+who doesn't know the library, mostly just referring you to the C++
+documentation.
+
+=item Gtk and Gtk2
+
+These are Perl bindings for the Gtk toolkit L<http://www.gtk.org>. The
+interface changed significantly between versions 1 and 2 so they have
+separate Perl modules. It runs under Unix, Win32 and Mac OS X (currently
+it requires an X server on Mac OS, but a 'native' port is underway), and
+the widgets look the same on every plaform: i.e., they don't match the
+native widgets. As with Wx, the Perl bindings follow the C API closely,
+and the documentation requires you to read the C documentation to
+understand it.
+
+=item Win32::GUI
-Tk is a completely Perl-based, object-oriented interface to the Tk toolkit
-that doesn't force you to use Tcl just to get at Tk. Sx is an interface
-to the Athena Widget set. Both are available from CPAN. See the
-directory http://www.cpan.org/modules/by-category/08_User_Interfaces/
+This provides access to most of the Win32 GUI widgets from Perl.
+Obviously, it only runs under Win32, and uses native widgets. The Perl
+interface doesn't really follow the C interface: it's been made more
+Perlish, and the documentation is pretty good. More advanced stuff may
+require familiarity with the C Win32 APIs, or reference to MSDN.
-Invaluable for Perl/Tk programming are the Perl/Tk FAQ at
-http://phaseit.net/claird/comp.lang.perl.tk/ptkFAQ.html , the Perl/Tk Reference
-Guide available at
-http://www.cpan.org/authors/Stephen_O_Lidie/ , and the
-online manpages at
-http://www-users.cs.umn.edu/%7Eamundson/perl/perltk/toc.html .
+=item CamelBones
+
+CamelBones L<http://camelbones.sourceforge.net> is a Perl interface to
+Mac OS X's Cocoa GUI toolkit, and as such can be used to produce native
+GUIs on Mac OS X. It's not on CPAN, as it requires frameworks that
+CPAN.pm doesn't know how to install, but installation is via the
+standard OSX package installer. The Perl API is, again, very close to
+the ObjC API it's wrapping, and the documentation just tells you how to
+translate from one to the other.
+
+=item Qt
+
+There is a Perl interface to TrollTech's Qt toolkit, but it does not
+appear to be maintained.
+
+=item Athena
+
+Sx is an interface to the Athena widget set which comes with X, but
+again it appears not to be much used nowadays.
+
+=back
=head2 How can I make my Perl program run faster?
Pass arrays and hashes by reference, not by value. For one thing, it's
the only way to pass multiple lists or hashes (or both) in a single
call/return. It also avoids creating a copy of all the contents. This
-requires some judgment, however, because any changes will be propagated
+requires some judgement, however, because any changes will be propagated
back to the original data. If you really want to mangle (er, modify) a
copy, you'll have to sacrifice the memory needed to make one.
5.8 the Filter::Simple and Filter::Util::Call modules are included in
the standard distribution), but any decent programmer will be able to
decrypt it. You can try using the byte code compiler and interpreter
-described below, but the curious might still be able to de-compile it.
-You can try using the native-code compiler described below, but
-crackers might be able to disassemble it. These pose varying degrees
-of difficulty to people wanting to get at your code, but none can
-definitively conceal it (true of every language, not just Perl).
+described later in L<perlfaq3>, but the curious might still be able to
+de-compile it. You can try using the native-code compiler described
+later, but crackers might be able to disassemble it. These pose
+varying degrees of difficulty to people wanting to get at your code,
+but none can definitively conceal it (true of every language, not just
+Perl).
It is very easy to recover the source of Perl programs. You simply
feed the program to the perl interpreter and use the modules in
solutions simply bundle a Perl interpreter in the final product
(but see L<How can I make my Perl program run faster?>).
-The Perl Archive Toolkit ( http://par.perl.org/index.cgi ) is Perl's
+The Perl Archive Toolkit ( http://par.perl.org/ ) is Perl's
analog to Java's JAR. It's freely available and on CPAN (
http://search.cpan.org/dist/PAR/ ).
-The B::* namespace, often called "the Perl compiler", but is really a way
-for Perl programs to peek at its innards rather than create pre-compiled
-versions of your program. However. the B::Bytecode module can turn your
-script into a bytecode format that could be loaded later by the
-ByteLoader module and executed as a regular Perl script.
-
There are also some commercial products that may work for you, although
you have to buy a license for them.
program for converting perl scripts to executable files. It targets both
Windows and unix platforms.
-=head2 How can I compile Perl into Java?
-
-You can also integrate Java and Perl with the
-Perl Resource Kit from O'Reilly Media. See
-http://www.oreilly.com/catalog/prkunix/ .
-
-Perl 5.6 comes with Java Perl Lingo, or JPL. JPL, still in
-development, allows Perl code to be called from Java. See jpl/README
-in the Perl source tree.
-
=head2 How can I get C<#!perl> to work on [MS-DOS,NT,...]?
For OS/2 just use
For example:
- # Unix
+ # Unix (including Mac OS X)
perl -e 'print "Hello world\n"'
# DOS, etc.
perl -e "print \"Hello world\n\""
- # Mac
+ # Mac Classic
print "Hello world\n"
(then Run "Myscript" or Shift-Command-R)
L<perlboot>, L<perltoot>, L<perltooc>, and L<perlbot> for reference.
A good book on OO on Perl is the "Object-Oriented Perl"
-by Damian Conway from Manning Publications, or "Learning Perl
-References, Objects, & Modules" by Randal Schwartz and Tom
-Phoenix from O'Reilly Media.
+by Damian Conway from Manning Publications, or "Intermediate Perl"
+by Randal Schwartz, brian d foy, and Tom Phoenix from O'Reilly Media.
=head2 Where can I learn about linking C with Perl?
=head2 What's MakeMaker?
-This module (part of the standard Perl distribution) is designed to
-write a Makefile for an extension module from a Makefile.PL. For more
-information, see L<ExtUtils::MakeMaker>.
+(contributed by brian d foy)
+
+The C<ExtUtils::MakeMaker> module, better known simply as "MakeMaker",
+turns a Perl script, typically called C<Makefile.PL>, into a Makefile.
+The unix tool C<make> uses this file to manage dependencies and actions
+to process and install a Perl distribution.
=head1 REVISION
-Revision: $Revision: 3606 $
+Revision: $Revision: 10127 $
-Date: $Date: 2006-03-06 12:05:47 +0100 (lun, 06 mar 2006) $
+Date: $Date: 2007-10-27 21:40:20 +0200 (Sat, 27 Oct 2007) $
See L<perlfaq> for source control details and availability.
=head1 AUTHOR AND COPYRIGHT
-Copyright (c) 1997-2006 Tom Christiansen, Nathan Torkington, and
+Copyright (c) 1997-2007 Tom Christiansen, Nathan Torkington, and
other authors as noted. All rights reserved.
This documentation is free; you can redistribute it and/or modify it