set-u3.0 revision 221463 
1203576Sjilles# $FreeBSD: head/tools/regression/bin/sh/expansion/set-u3.0 221463 2011-05-04 22:12:22Z jilles $
2203576Sjilles
3203576Sjillesset -u
4203576Sjillesunset x
5203576Sjillesv=$( (eval ': $((x))') 2>&1 >/dev/null)
6203576Sjilles[ $? -ne 0 ] && [ -n "$v" ]
7203576Sjilles