You can use the special variable $^O to see what your script is running upon:

#!/usr/bin/perl -w

use strict;

print "This is : $^O \n";
if ( $^O =~ /win/i )
{
   print "Looks like Windows\n";
}
if ( $^O =~ /linux/i )
{
   print "Looks like Linux\n";
}
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(Note: That is "capital o", not "zero".)