1T=`mktemp -d ${TMPDIR:-/tmp}/sh-test.XXXXXXXX` 2trap 'rm -rf "$T"' 0 3cd "$T" || exit 3 4mkfifo fifo1 || exit 3 5set -T 6trap "for i in 1 2 3 4; do sleep 1 & done" USR1 7sleep 1 & 8{ kill -USR1 "$$"; echo .; } >fifo1 & 9(read dummy <fifo1) 10