Kill Cat After Background Process Ends

Question

Running a C# program with mono under Cent OS. There is a fifo that allows external input to go into this program.

I also have cat to accept input from the screen session the mono program is running in.

#! /bin/bash -
echo "Starting server"
mono --gc=sgen Server-CLI.exe < $fifo &
echo $$ > $PIDFILE
cat > $fifo
echo "Server stopped. Cleaning up"
rm -f $fifo
rm -f $PIDFILE

How can I make cat exit whenever the mono program exits? Right now if the mono program exits, cat is still running so the script never reaches the 2nd echo.

Answer 1

Save the PID of mono. Run cat in the background and save its PID. wait for the PID of mono. When this is satisfied, kill the PID of cat.

mono &
monoPID=$!
cat &
catPID=$!
wait "$monoPID"
kill "$catPID"