update: since the OP replaced his original question, the answer below doesn't make much sense.

There is an example snippet right at the top of the module's documentation: 
         use Getopt::Long;
         my $data   = "file.dat";
         my $length = 24;
         my $verbose;
         $result = GetOptions ("length=i" => \$length,    # numeric
                               "file=s"   => \$data,      # string
                               "verbose"  => \$verbose);  # flag

[download]

This will set the $length, $data and $verbose variables according to the --length (with integer value), --file (with string value) and --verbose (boolean switch) options passed to the script.

Getopt::Long does indeed have only one public function in its API, because you don't need more than one function. Your statement that every Java API has more than one method is wrong: here's one with only 1 method

A module is just perl code in a file that has a .pm extension. It doesn't even have to have any public methods/functions.

See perlmod and perlmodlib for much more info about using and creating modules.

"What should it profit a man, if he should win a flame war, yet lose his cool?"

In reply to Re: Examples for using Getopt::Long by Joost
in thread Examples for using Getopt::Long by bahadur

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.