It looks like you've already got the the optional arguments handled correctly in your subroutine, but you're passing it a hash reference where it expects a plain list. Change your subroutine invocation to: 

StartCapture( 
  twigs   => {filter => $filterTwig,  capture => $captureTwig},
  hashes  => {filter => \%filterHash,  capture => \%captureHash},
  files   => {filter => 'filter.txt', capture => 'capture.txt'}, 
  results => 'c:/temp.txt' 
            );

[download]

Notice that I also changed %captureHash and %filterHash to \%captureHash and \%filterHash so they are passed as references instead of flattening into lists.

To access nested elements, you can do something like $args{twigs}{filter}. For more, see perlreftut and perldsc.

In reply to Re: Optional and default parameters for a subroutine by friedo
in thread Optional and default parameters for a subroutine by ramya2005

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.