# this reports a problem if func() fails.
func $arg1, $arg2 or warn "error invoking func()";

# so does this
func( $arg1, $arg2 ) || warn "error invoking func()";

# Not what you might expect
# this invokes func( $arg1, ($arg2 || warn "error invoking func()" );
func $arg1, $arg2  || warn "error invoking func()";