How to retrieve the arguments from command prompt using Getopt::Long?

Question

The requirement is

perl prg.pl --product --param Product1 --from FilePath

where --product specifies the reference to the function that has to accept the parameter Product1, and the FilePath is the path of the file to be searched for the product.

GetOptions('product=s'=>\&getproduct, 'param=s'=>\$param,'from=s'=>\$from);

In spite of this, while running the Perl program, it gives an error that the values product and from are uninitialized. Can you help me solve this issue?

`getproduct` is to be passed as an reference. So it should be `'product=s' => \&getproduct` and also `param` and `from`. — vkk05, Jun 21 '20 at 11:19
In the future, please provide the error messages, and please provide a minimal, runnable demonstration of the problem. — ikegami, Jun 21 '20 at 13:03

ikegami · Accepted Answer · 2020-06-21T13:09:37.687

You indicate that the product option requires a value (=s), so

             Value for --product. (Not an option.)
             |
             |       Doesn't start with `-`, so option parsing ends.
             |       |
          vvvvvvv vvvvvvvv
--product --param Product1 --from FilePath
                  ^^^^^^^^^^^^^^^^^^^^^^^^
                             |
                             Not options, so found in @ARGV.

Fix:

GetOptions(
   'help|h|?' => \&help,
   'product'  => \$product,
   'param=s'  => \$param,
   'from=s'   => \$from,
)
   or usage();

@ARGV == 0
   or usage("Too many arguments.");

See this for a sample implementation of usage and help.

How to retrieve the arguments from command prompt using Getopt::Long?

1 Answers1