shell/ash_test/ash-arith/arith-postinc.tests - busybox - Git at Google

 echo 1 $((0++1))
 echo 1 $((0--1))
 x=-1; echo 1 $((0-$x))
 x=+1; echo 1 $((0+$x))
 echo Ok:$?
	echo 1 $((0++1))
	echo 1 $((0--1))
	x=-1; echo 1 $((0-$x))
	x=+1; echo 1 $((0+$x))
	echo Ok:$?