--- /dev/null
+: ${TMPDIR:=/var/tmp}
+SHELLSFILE=$TMPDIR/shells-$$
+
+cat > $TMPDIR/shells-$$ <<EOF
+/bin/bash
+/bin/csh
+/bin/ksh
+/bin/sh
+/bin/tcsh
+/bin/zsh
+EOF
+
+oclosev()
+{
+exec {v}>&-
+}
+
+iclosev()
+{
+exec {v}<&-
+}
+
+exec {v}>&1
+echo $v
+
+echo foo 1 >&$v
+echo foo 2 >&$v
+echo foo 3 >&$v
+
+oclosev
+
+exec {v}<$SHELLSFILE
+echo $v
+
+while read line <&$v
+do
+ echo $line
+done
+
+iclosev
+
+type oclosev
+type iclosev
+
+while read -r -u ${fd}
+do
+ echo $REPLY
+done {fd}<$SHELLSFILE
+
+rm -f $SHELLSFILE
+
+exit 0