#!/usr/bin/env perl

use strict;
use warnings;

use Data::Dump;
use Getopt::Long qw{GetOptionsFromString};

my ($x, $y, $z) = (0, 0, 0);
my %opts = ('x=i', \$x, 'y=i', \$y, 'z=i', \$z);

dd \%opts;

GetOptions(%opts);

dd \%opts;

print 'Enter new: ';
chomp(my $new = <>);

GetOptionsFromString($new, %opts);

dd \%opts;

##</code><code>##

$ pm_1184309_getopt_long_opts_from_string.pl -x 1 -y 2
{ "x=i" => \0, "y=i" => \0, "z=i" => \0 }
{ "x=i" => \1, "y=i" => \2, "z=i" => \0 }
Enter new: -y 3 -z 4 -x 0
{ "x=i" => \0, "y=i" => \3, "z=i" => \4 }