in reply to How to compare elements within an array
One option is to use a hash to track the lab count (using the lab numbers as keys, so they can be numerically sorted later). If the count is 2, then the lab is paired, else it's unpaired:
use strict; use warnings; my %hash; while (<DATA>) { $hash{$1}++ if /^lab(\d+)_/; } for my $lab ( sort { $a <=> $b } keys %hash ) { print "lab$lab is ", ( $hash{$lab} == 2 ? 'paired' : 'unpaired' ), + "\n"; } __DATA__ lab1_set1.txt lab1_set2.txt lab2_set1.txt lab3_set1.txt lab3_set2.txt
Output:
lab1 is paired lab2 is unpaired lab3 is paired
Hope this helps!
In Section
Seekers of Perl Wisdom