Getopt::Long::Configure ("bundling_values", "ignorecase_always");
my $myOpt = 0;
GetOptions('S=i'=> \$myOpt);
print "bundling_values, ignorecase_always\n";
print "$myOpt\n\n";

$ test.pl -S1
bundling_values, ignorecase_always
1

$ test.pl -s1
bundling_values, ignorecase_always
1