#!/usr/bin/env perl use strict; use warnings; use autodie; use Text::CSV; my ($f1, $f2) = qw{pm_1208339_1.csv pm_1208339_2.csv}; my %f1_values; my $csv = Text::CSV::->new; get_f1_data($f1, $csv, \%f1_values); parse_f2_data($f2, $csv, \%f1_values); sub get_f1_data { my ($file, $csv_obj, $f1_values) = @_; open my $fh, '<', $file; while (my $row = $csv_obj->getline($fh) ) { push @{$f1_values{$_}}, $row for @$row; } return; } sub parse_f2_data { my ($file, $csv_obj, $f1_values) = @_; open my $fh, '<', $file; while (my $row = $csv_obj->getline($fh) ) { my $matches = 0; print 'In line: '; $csv_obj->say(\*STDOUT, $row); for my $value (@$row) { next unless exists $f1_values->{$value}; ++$matches; print " $value found in:\n"; for my $line (@{$f1_values->{$value}}) { print ' '; $csv_obj->say(\*STDOUT, $line); } } print " No matches found\n" unless $matches; } return; }