Invalid type in unpack: '(' at g.pl line 3.

##</code><code>##

use strict;
sub commify {
    reverse scalar join ',',
    unpack '(A3)*',
    reverse scalar shift;
}
sub commify2 {
    scalar reverse join ',',
    unpack '(A3)*',
    reverse scalar shift;
}
my $x = commify(1234);
my $y = commify2(1234);
print "x='$x' y='$y'\n";
print "comm :", commify(1234), ":\n";
print "comm2:", commify2(1234), ":\n";

##</code><code>##

x='1,234' y='1,234'
comm :432,1:
comm2:1,234: