convenientstore has asked for the wisdom of the Perl Monks concerning the following question:

not sure why below is not working?
am I calling it the wrong way?
I tried ./programname -h and thinking it was gonna print out the usage and exit
#!/usr/bin/perl -w

use strict;

use Getopt::Std;

sub usage {
        print <<NOW;

        usage : $0 [-h] -l<something> -t<somethig> -f<file>

        syntax:
            -h
                prints this help text and exists

            -l
               sometihng 

            -t
                someting 

            -f
                something 
NOW
            exit 0;
}


my $o={} ; getopt('hltf', $o); 
#usage() if $$o{h};
if ($$o{h}) {
  usage();  
}

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Re: getopt::std help
by davidrw (Prior) on Jan 07, 2008 at 02:45 UTC
    Add this to see what's going on: 
    use Data::Dumper;
print Dumper $o;

    [download]
    And you'll see that the key 'h' _is_ being created, and the value is undef, which is why your if statements don't pick it up, since it's a false value. This will do what you want: 
    usage() if exists $o->{h};

    [download]
[reply]
[d/l]
[select]
      doh..
      Thank you.
      One more thing, will using getopt automatically reject the flags that are not explicitly specified (getopt('hltf', $o);), meaning if I call a program w/ ./program -x ,
      Will getopt automatically reject and abort the program or do I need to tell the program that?
[reply]

        Try running ./program -x and see what happens. Sometimes the best way to learn is to experiment;)

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