if (...) {
    ...
    return;
}

... # "else" stuff

##</code><code>##

while (<$channel>) {push @output, $_}
#becomes
push @output, $_ while <$channel>;
#although
my @output = <$channel>;
#is even better

##</code><code>##

    for my $i (@show_inventory) {
        my $inv_line1 = shift @show_inventory;
        my $inv_line2 = shift @show_inventory;

##</code><code>##

    while (@show_inventory) {
        my $inv_line1 = shift @show_inventory;
        my $inv_line2 = shift @show_inventory;