There is another way to handle the return value in a loop. Instead of returning a string, return an object that overloads the boolean, numerical, and string operators.

An example of this in practice is the IO::Prompt module on cpan. Here is an excerpt of the source:

package IO::Prompt::ReturnVal;

use overload
    q{bool} => sub {
        $_ = $_[0]{value} if $_[0]{set_val};
        $_[0]{handled} = 1;
        $_[0]{success};
    },
    q{""} => sub { $_[0]{handled} = 1; "$_[0]{value}"; },
    q{0+} => sub { $_[0]{handled} = 1; 0 + $_[0]{value}; },
    fallback => 1,
    ;

sub DESTROY {
    $_ = $_[0]{value} unless $_[0]{handled};
}
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As you can see, it also provides mechanisms for setting $_.

Anyway, just wanted to throw out another option. Please note that the IO::Prompt module only runs on unix based systems currently AFAIK.

- Miller