Regarding the conflict between options... perhaps this (KISS in play):-

# to check on conflicting switches

use Getopt::Std;

# Switches and Invalid combinations
# NOTE: conflicts must be specified in alphabetical order!

@switches         = ();         # List of supplied switches

@switch_conflicts = ( "lp",     # portrait and landscape
                      "lpv",    # portrait, landscape, view-only
                      "pv"      # portrait, view-only
                    );

# ----------

getopts("plv");

# ---------- Specify switches on CLI

if (defined($opt_p)) {
   push(@switches, "p");
}

if (defined($opt_l)) {
   push(@switches, "l");
}

if (defined($opt_v)) {
   push(@switches, "v");
}

$switch_list = "";
foreach $item (sort @switches) {
   $switch_list .= $item;
}

# ------

foreach $item (@switch_conflicts) {
   if ($switch_list =~ /$item/) { # Get out at earliest opportunity
       printf("\nERROR: Invalid combination of switches, /%s/\n", $ite
+m);
        die("\n");
    }
}

printf("\nSwitches are all Ok.\n");

exit(0);
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The main thing with doing things this way is that it's relatively simple to add a new switch (and its conflicts), update the 'getopts()' string and add an additional (basic) 'opt_x'... and it should be easy enough to turn this whole thing into a sub{} or similar...

Any other thoughts?

Fanx! again for all the posts... and I'm still pondering the switch checking/function execution side of things...