# simple menu/input collection
enter word: foo
you entered <foo>
enter word: q
quitting...

##</code><code>##

sub check_input {
	my $input = shift;

	return $input if length($input) != 1;
	if ($input eq 'q') {
		exit
	}
	elsif ($input eq 'b') {
		...
	}
	else {
		print 'not recognized';
	}
}

##</code><code>##

sub check_input {
	my ($type, $input) = @_;

	return $input if length($input) != 1;
	exit if $input eq 'q'; # etc for universal options

	# handle prompt types
	if ($type eq 'start') {
		if ($input eq 'n') {
			# do something useful with currently out-of-scope variables
			...
			# (uh oh)
		}
	}
	# etc, etc
}

##</code><code>##

while(1) {
	my $input = <>;
	chomp $input;
	check_input('ptype', $input);
}
BREAK:
...
# sub check_input
if ($input eq 'b') {
	goto BREAK:
}

##</code><code>##

my @working = (1 .. 10);
# globally scoped anonymous coderef
my $push = sub { push @working, shift };
my $pop = sub { pop @working };
while(1) {
	my $input = input();
	check_input('type', $input);
}
...
# sub check_input
if ($input eq 'p') {
	$pop->();
}

##</code><code>##

sub check_input {
	my ($input, $opts_href) = @_;
	return $input if length($input) != 1;
	exit if $input =~ m/Q|c/;
	
	$opts_href->{$input}->() 
		if defined $opts_href->{$input} && ref $opts_href->{$input} eq 'CODE';
		
}
...
# define non-global options hash in menu scope
my %opts_hash = (
    a =>	sub { goto SOMESPOT },
    o =>	sub { print "continue? (y/N): "; 
                      $input = input();
                      pop @working if $input =~ m/^y$/i;                    
		    },
    'default' => sub { say "error: please select 'a', 'o', or 'c'" },
);
...
# cannot find this label!
sub elsewhere {
...
SOMESPOT:
...
}