From your description, it sounds like what you want is something closer to 

my ( $x_opt, $y_opt, $z_opt );
my $status = GetOptions( x => \$x_opt,
                         y => \$y_opt,
                         z => \$z_opt,
                       );

die $USAGE if !$status ||
              !@ARGV   ||
              ( 1 < grep $_, $x_opt, $y_opt, $z_opt ) ||
              ( $x_opt and @ARGV != 4 ) ||
              ( $y_opt and @ARGV != 3 ) ||
              ( $z_opt and @ARGV != 2 );

[download]
The last line dies if any one of these conditions holds:
  1. GetOptions failed for some reason (hence $status will be false);
  2. No arguments (@ARGV is empty);
  3. More than one of -x, -y, and -z were specified on the command line (the grep expression will return a list of more than one item in this case);
  4. -x, -y, or -z was specified with the wrong number of arguments.

Updates: Added remarks to explain the last statement. Changed warn $USAGE and exit 1 to the less flexible but simpler die $USAGE.

the lowliest monk

In reply to Re: Getopt::Long making use of $ARGV[n] by tlm
in thread -x accepts up to 3 additional arguments by tcf03

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.