Shell Programming and Scripting

#!/usr/bin/perl
use strict;
sub l_sort{
	my($a,$b)=(@_);
	my @t1=split("[,|  ]",$a);
	my @t2=split("[,|  ]",$b);
	return $t1[$#t1] <=> $t2[$#t2];
}
open FH,"<a.txt";
while(<FH>){
	#chomp;
	my @tmp=split("[,|  ]",$_);
	push @{$hash{$tmp[$#tmp-1]}}, $_;
}
for $k(sort keys %hash){
	print sort {l_sort($a,$b)} @{$hash{$k}} if $k % 2 != 0;
	print sort {l_sort($b,$a)} @{$hash{$k}} if $k % 2 == 0;		
}