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Can Getopt :: Long GetOptions throw an error if the same option occurs multiple times?

I have this getopt:

GetOptions(  GetOptions ("library=s" => \@libfiles);
    @libfiles = split(/,/,join(',',@libfiles));
     "help" => \$help,
     "input=s" => \$fileordir,
     "pretty-xml:4" => \$pretty
);

Is it possible to Getopt::Long::GetOptions

find that the same option is provided on the command line multiple times? For example, I would like the following to generate an error:

perl script.pl --input=something --input=something

thank

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1 answer


I don't think there is a direct route, but you have two options:



  • Use an array and check after processing the parameters

    #!/usr/bin/perl

use warnings;
use strict;

use Getopt::Long;

my @options;
my $result = GetOptions ('option=i' => \@options);

if ( @options > 1 ) {
   die 'Error: --option can be specified only once';
}

  • Use a subroutine and make sure the parameter is already defined

    #!/usr/bin/perl

use warnings;
use strict;

use Getopt::Long;

my $option;
my $result = GetOptions (
    'option=i' => sub {
        if ( defined $option) {
            die 'Error: --option can be specified only once';
        } else {
            $option = $_[1]; 
        }
    }
);

    In this case, you can use an exclamation mark !

    at the beginning die

    and the error will be caught and declared as a regular Getopt error (see the Getopt :: Long documentation for details)

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