I guess at compile time, they go through from top to bottom to see if things have been decalred... and when it finds those variable not defined, it throws an exception(?)... sa per you guys suggestion, I throw definition on top and it works.. thank you. 
!/usr/bin/perl -w

use strict;
use diagnostics;
use Getopt::Long;

my ($server, $proc, $prog);

sub usage {
    print "this is wrong\n";
    exit 0;
}

sub san_check_arg {
        usage () if $#ARGV  != 0;
        if (defined($server)) {
            return ($server);
        } elsif (defined($proc && $prog)) {
            return ($proc,$prog);
        } else {
          usage();
        }
}


my $val1 = eval { GetOptions (
                        "help"      => sub { usage() },
                        "server=s"  => \$server,
                        "process=s"      => \$proc,
                        "program=s"  => \$prog
)};
die                                   usage() if $@;  #alone

if (!$val1) {
      usage();
}


my @ar = san_check_arg();  #check users input sanity
print "@ar\n";

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In reply to Re^2: Getopt question again by convenientstore
in thread Getopt question again by convenientstore

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