$substr = sub {
   if (@_ == 2) {
      return substr($_[0], $_[1]);
   } elsif (@_ == 3) {
      return substr($_[0], $_[1], $_[2]);
   } elsif (@_ == 4) {
      return substr($_[0], $_[1], $_[2], $_[3]);
   } else {
      require Carp;
      Carp::croak("Bad arguments for substr");
   }
};

print($substr->('abc', 1), "\n");