use Data::Roundtrip qw/json2perl/;
use File::Temp; 
use strict;
use warnings;

my $cmdlinestr = <<EOC;
-x 123 -y 'some val'
EOC
 
my ($fh, $fn) = File::Temp::tempfile();
print $fh 'use Data::Roundtrip qw/perl2json/; print perl2json(\@ARGV)'; 
close $fh; 

my $ret = `$^X ${fn} ${cmdlinestr}`;  
my $args = json2perl($ret);

print join("\n", @$args)."\n";