Command line arguments

#!/usr/bin/env perl
#
use strict;

if( scalar( @ARGV) == 0)
{
    print "\nUsage:\n";
    print "'./CheckVersion.pl 1' for all Debian hosts \n";
    print "'./CheckVersion.pl 2' for hosts in ~/bin/ExpPCs.lis \n";
    exit();
}

if( $ARGV[0] == '1')
{
    print "all Debian hosts at FS\n"; 
    @nodes = `ssh root\@haso107d1 "mco find -S 'tango_db=true or tango_db=false' --dt 10 "`;
}
elsif( $ARGV[0] == '2')
{
    print "reading ~/bin/ExpPCs.lis\n"; 
    @nodes = `cat ~/bin/ExpPCs.lis`;
}