As the author of Getopt::Long always says, options are optional, or they wouldn't be options. So the "they may or may not be present" isn't anything special. In fact, it's the bread and butter of Getopt::Long - it only deals with things that may or may not be present.

If you make the call syntax like: 

findfiles --input data modem apps --nd --na --nc --des "..." -r 1000

[download]
Something like: 
GetOptions 'input=s{0,}'  =>  \my @input,
           'na'           =>  \my $na,
           'nd'           =>  \my $nd,
           'nc'           =>  \my $nc,
           'des=s'        =>  \my $des,
           'r=i'          =>  \my $r;

[download]
Should do the trick.

In reply to Re^5: Dynamic option by JavaFan
in thread Dynamic option by Anonymous Monk

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.