$MAKE_COMMAND -n $INSTALL_RULE > "$LOG_DIR"/$NAME-test-make-install.log 2> /dev/null &
			# so we can get the process pid
			PID=$!
			# sleep a trivial amount of time
			sleep 1
			# if the directory /proc/$PID exists, then the process is still running
			if [[ -d /proc/$PID ]] ; then
				# we are in a 'race' condition anyway, so silence any error output
				# interrupt the process first to avoid nasty error output
				(kill -INT $PID) &> /dev/null
				# (kill -KILL $PID) &> /dev/null
				STATUS=SUCCESS
			else
				# otherwise, the process either failed or succeeded very quickly
				# so run it again and check the exit status directly
				# $MAKE_COMMAND -n "$INSTALL_RULE" > "$LOG_DIR"/$NAME-test-make-install.log &> /dev/null
				$MAKE_COMMAND -n "$INSTALL_RULE" &> "$LOG_DIR"/$NAME-test-make-install.log
				ERR=$?
				case $ERR in
					0) STATUS=SUCCESS ;;
					*) STATUS=FAILED ;;
				esac
			fi

#!/bin/bash
# Use subshells, $?, and temp files to see return status of background jobs.

if [ -e tmpfile1 ] ; then
        rm tmpfile1
fi

if [ -e tmpfile2 ] ; then
        rm tmpfile2
fi

(invalidcmd ; echo $? > tmpfile1) &> /dev/null &
(whoami ; echo $? > tmpfile2) &> /dev/null &

echo "Doing other stuff now."
sleep 1

echo "The return value of the first command was `cat tmpfile1`."
echo "The return value of the second command was `cat tmpfile2`."

#!/bin/bash
# Use subshells, $?, and temp files to see return status of background jobs -- and watch it break.

# These jobs take too long to finish:

(sleep 2 ; doodles &> /dev/null ; echo $? > tmpfile1) > /dev/null &
(sleep 2 ; whoami &> /dev/null ; echo $? > tmpfile2) > /dev/null &

echo "Doing other stuff now."

# One error for each 'cat' and 'rm', and blank values:

echo "The return value of the first command was `cat tmpfile1`."
echo "The return value of the second command was `cat tmpfile2`."

rm tmpfile1
rm tmpfile2

#!/bin/bash
# Cleaner code calling a function as the last command in the subshell

cmdfinished() {
       # Takes 2 arguments, "command name" and "return value" 
       echo "The return value of command $1 was $2."
}

(sleep 1 ; invalidcmd &> /dev/null ; cmdfinished invalidcmd $?) &
(sleep 1 ; whoami &> /dev/null ; cmdfinished whoami $?) &

echo "Doing other stuff now without worrying about when the results come in."

while read job; do wait $job; echo $job $?; done < <( jobs -p )

#!/bin/bash
set -m # enable job control

TIME=${1:-10}
EXIT_STATUS=${2:-0}
SCRIPT_PID=$$

STATUS=FAILED
FINISHED=NO

trap 'wait $PID && STATUS=SUCCESS; FINISHED=YES' SIGUSR1
# sleep $TIME is instead of make, for easier testing
(sleep $TIME; kill -s SIGUSR1 $SCRIPT_PID; exit $EXIT_STATUS) &
PID=$!

# sleep a trivial amount of time
sleep 1

if [ "$FINISHED" = NO ] ; then
    # we are in a 'race' condition anyway, so silence any error output
    # interrupt the process first to avoid nasty error output
    # except silencing here doesn't work now
    kill -KILL $PID
    STATUS=SUCCESS
fi

# have to redirect before this echo otherwise it doesn't work!?
exec 2>/dev/null
echo "STATUS: $STATUS; FINISHED: $FINISHED"

~/tmp$ TIMEFORMAT='real %R'
~/tmp$ time ./jobs.sh 0 0 # finish quickly with successful exit
STATUS: SUCCESS; FINISHED: YES
real 1.026
~/tmp$ time ./jobs.sh 0 1 # finish quickly with failure on exit
STATUS: FAILED; FINISHED: YES
real 1.024
~/tmp$ time ./jobs.sh 4 0 # take a while to finish
STATUS: SUCCESS; FINISHED: NO
real 1.024