This isn't perfect, but I find it convenient.
use Getopt::Long;

%opt_ctl = (         "recipient_of_message|r=s@", \@recips,
#                                       "URLs_to_use|u=s@", \@urls_in,
                  "do_all_VIPs_except_those_expected_down|a!", \$all,
                  "do_all_VIPs_without_excepotions|awe!", \$awe,
                                    "timeout_for_gets|t=i", \$timeout,
                                           "show_usage|h!", \$sho_usag
+e,
                                                "debug|d=i", \$debug,
      "select_this_proxy_-_1_or_3_or_user_specified|p=s", \$proxy_sel,
                                        "smtp_server|s=s", \$smtpsrvr,
                                "time_between_cycles|w=i", \$wait,
                                  "no_mail_sent_ever|nm!", \$no_mail,
                                           "no_proxy|np!", \$no_proxy,
);


Getopt::Long::Configure( qw(no_auto_abbrev) );

$debug = 0;

if ( not GetOptions(%opt_ctl) or $sho_usage ) { usage() }


sub usage
{
    (@f, %switch, $out, ) = ( );

    # $out = "\nUsage:\n\n$0 [ -t timeout ] [ -p 1 | -p 3 | -p proxy_U
+RL] [ -e ] [ -a ] [ -d ] [ -w wait ]\n";

    #self-document switch options
    for ( keys %opt_ctl )
    {
        @f = split(/\||=|!/);
        $switch{$f[1]} = $f[0];
    }
    for ( sort keys %switch )
    {
        $def = $switch{$_};
        $def =~ s/\_/ /g;
        $_ = '-' . $_;
        $out .= sprintf "%4s: %s\n", $_, $def;
    }

    print "$out\n";
    exit;
}

[download]

Replies are listed 'Best First'.
Re: "self documenting" switch options
by halley (Prior) on Jul 27, 2003 at 03:21 UTC

    Why stunt the capabilities of getopt by shoehorning in other kinds of information in its switch strings?

    In such cases, I usually just make a more complex structure which associates getopt switches to arrays which contain variables, help texts, validator functions and whatever else. Then I just map out the elements that Getopt::Long expects. For --help, I can also look at the switch strings and other clues to automate some of the messages for consistency.

    This code is a sketch from memory. There are other structures that would do just as well. 

    my $Verbose;
my $Secret;
%Options = {
   'verbose+' => [ \$Verbose,
                   "Makes the output more verbose." ],
   'secret!' => [ \$Secret,
                  "Enables secret features." ],
};

...

sub usage {
  ...
  foreach my $option (sort keys %Options) {
    my $switch = $option;
    $switch =~ s/=.*$//;
    $switch =~ s/\W*$//;
    $message = $Options{$option}[1];
    $message .= " Adding $switch increases the effect."
      if $option =~ /\+$/;
    $message .= " Use --no$switch to disable."
      if $option =~ /\!$/;
    print Wrap(undef, undef, "$switch: $message"), $/;
}

...

GetOptions(map { $_, $Options{$_}[0] } keys %Options);

    [download]

    (One should mention the POD::Usage here, but I find it a little stiff, personally.)

    --
    [ e d @ h a l l e y . c c ]

[reply]
[d/l]
[select]

      Why stunt the capabilities of getopt by shoehorning in other kinds of information in its switch strings?

      Because I never use the long option names and this lets me have it all in 1 place, so it's almost impossible to forget to document the option. As I said previously, not perfect, but convenient.

      Update: I'm going to stop posting when my caffeine level is low. Your solutions does keep it all in once place, without imposing limitations on the descriptions as I had to. I'll probably start using your method for future work. You should post yours as a snippet.

      Your solution also illustrates something I've heard elsewhere and found invaluable: "complicated data structures are better than complicated code". Or maybe it was "better data structures make better code". Whatever it was, your example has more of it than mine.

      --Bob Niederman, http://bob-n.com
[reply]
Re: "self documenting" switch options
by rob_au (Abbot) on Jul 27, 2003 at 06:02 UTC
[reply]

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