$a = "1234567890";
$a =~ s/(\d)/$1 x $1/g;
print $a, "\n";
$a =~ s/(\d)/$1 x $1/ge;
print $a, "\n";
$a =~ s/(\d{2})/$1 x $1/g;
print $a, "\n";
$a =~ s/(\d{2})/$1 x $1/ge;
print $a, "\n";