use warnings;
use strict;

my $string1 = "one=1,two=2,three=3,four=4,five=5";
my $string2 = "one=1,three=3,five=5";

for ($string1, $string2) {
	print "$_\n";
	print "$1=$2\n" while /(\w+)=(\d+)/g;
}