Re: Options with optional values and condititions

in reply to Options with optional values and condititions

I think the logic you mean is:

use strict;
use warnings;
use Getopt::Long;

my $foo = undef;

GetOptions(
    'foo:s' => \$foo,
);

my $sn = $ARGV[0];

if (not defined $foo) {
    print "foo option not used at all \n";
} elsif (not length $foo) {
    print "foo option used with no optional value \n";
} else {
    print "foo option used with optional value: $foo \n";
}
[download]

I used the length test because 0 is a potentially valid input but evaluates to false in logical context. This would also hold for a whitespace-only input, e.g.:

perl script.pl --foo=' '

#11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.

In Section Seekers of Perl Wisdom