##ALSO UNTESTED
while (<FH>) {
    my ($col1, $col2) = split m/\s+/;
    stuff_i_need_do($col1) if ( check_for_condition(\%files,$col2) );
}

sub check_for_condition {
    my $files = shift || return undef;
    my $col   = shift || return undef;
    foreach my $file ( keys %{$files} ) {
        return 1 if (exists $files{$file}{$col2} );
    }
    return undef;
}

sub stuff_i_need_to_do {
   my $stuff = shift;
   #do something;
}