How can I allow undefined options when parsing args with Getopt

Question

If I have a command line like:

my_script.pl -foo -WHATEVER

My script knows about --foo, and I want Getopt to set variable $opt_foo, but I don't know anything about -WHATEVER. How can I tell Getopt to parse out the options that I've told it about, and then get the rest of the arguments in a string variable or a list?

An example:

use strict;
use warnings;

use Getopt::Long;

my $foo; 

GetOptions('foo' => \$foo); 

print 'remaining options: ', @ARGV;

Then, issuing

perl getopttest.pl -foo -WHATEVER

gives

Unknown option: whatever
remaining options:

Answer 1

You need to configure "pass_through" option via Getopt::Long::Configure("pass_through");

Then it support actual options (e.g. stuff starting with "-" and without the special "--" delimiter to signify the end of "real" options).

Here's perldoc quote:

• pass_through (default: disabled)

  Options that are unknown, ambiguous or supplied with an invalid option value are passed through in @ARGV instead of being flagged as errors. This makes it possible to write wrapper scripts that process only part of the user supplied command line arguments, and pass the remaining options to some other program.

Here's an example

$ cat my_script.pl
#!/usr/local/bin/perl5.8 -w

use Getopt::Long;
Getopt::Long::Configure("pass_through");
use Data::Dumper;
my %args;
GetOptions(\%args, "foo") or die "GetOption returned 0\n";
print Data::Dumper->Dump([\@ARGV],["ARGV"]);

$ ./my_script.pl -foo -WHATEVER          
$ARGV = [
          '-WHATEVER'
        ];