script_template.pl

#!/usr/bin/env perl

=head1 NAME

template.pl - you should put a one-line description of your script here

=head1 SYNOPSIS

USAGE: template.pl 
            --some_argument=/path/to/some_file.fsa 
            --another_argument=/path/to/somedir
          [ --optional_argument=/path/to/somefile.list 
            --optional_argument2=1000
          ]

=head1 OPTIONS

B<--some_argument,-i>
    here you'll put a longer description of this argument that can span multiple lines. in 
    this example, the script has a long option and a short '-i' alternative usage.

B<--another_argument,-o>
    here's another named required argument.  please try to make your argument names all
    lower-case with underscores separating multi-word arguments.

B<--optional_argument,-s>
    optional.  you should preface any long description of optional arguments with the
    optional word as I did in this description.  you shouldn't use 'optional' in the
    actual argument name like I did in this example, it was just to indicate that
    optional arguments in the SYNOPSIS should go between the [ ] symbols.

B<--optional_argument2,-f>
    optional.  if your optional argument has a default value, you should indicate it
    somewhere in this description.   ( default = foo )

B<--log,-l> 
    Log file

B<--help,-h>
    This help message

=head1  DESCRIPTION

put a longer overview of your script here.

=head1  INPUT

the input expectations of your script should be here.  pasting in examples of file format
expected is encouraged.

=head1  OUTPUT

the output format of your script should be here.  if your script manipulates a database,
you should document which tables and columns are affected.

=head1  CONTACT

    Your Name
    you@wherever.com

=cut

use warnings;
use strict;
use Getopt::Long qw(:config no_ignore_case no_auto_abbrev pass_through);
use Pod::Usage;

my %options = ();
my $results = GetOptions (\%options, 
                          'some_argument|i=s',
                          'another_argument|o=s',
                          'optional_argument|s=s',
                          'optional_argument2|f=s',
                          'log|l=s',
                          'help|h') || pod2usage();

## display documentation
if( $options{'help'} ){
    pod2usage( {-exitval => 0, -verbose => 2, -output => \*STDERR} );
}

## make sure everything passed was peachy
&check_parameters(\%options);

## open the log if requested
my $logfh;
if (defined $options{log}) {
    open($logfh, ">$options{log}") || die "can't create log file: $!";
}

##
## CODE HERE
##

exit(0);


sub _log {
    my $msg = shift;

    print $logfh "$msg\n" if $logfh;
}


sub check_parameters {
    my $options = shift;
    
    ## make sure required arguments were passed
    my @required = qw( some_argument another_argument );
    for my $option ( @required ) {
        unless  ( defined $$options{$option} ) {
            die "--$option is a required option";
        }
    }
    
    ##
    ## you can do other things here, such as checking that files exist, etc.
    ##
    
    ## handle some defaults
    $options{optional_argument2}   = 'foo'  unless ($options{optional_argument2});
}