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Re: Options with optional values and condititions

by kennethk (Abbot)
on Oct 02, 2012 at 16:14 UTC ( #996879=note: print w/ replies, xml ) Need Help??

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"; }

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 --foo='   '

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

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