How to get process ID of background process?
You need to save the PID of the background process at the time you start it:
foo &FOO_PID=$!# do other stuffkill $FOO_PIDYou cannot use job control, since that is an interactive feature and tied to a controlling terminal. A script will not necessarily have a terminal attached at all so job control will not necessarily be available.
You can use the jobs -l command to get to a particular jobL
^Z[1]+ Stopped guardmy_mac:workspace r$ jobs -l[1]+ 46841 Suspended: 18 guardIn this case, 46841 is the PID.
From help jobs:
-l Report the process group ID and working directory of the jobs.
jobs -p is another option which shows just the PIDs.
$$is the current script's pid$!is the pid of the last background process
Here's a sample transcript from a bash session (%1 refers to the ordinal number of background process as seen from jobs):
$ echo $$3748$ sleep 100 &[1] 192$ echo $!192$ kill %1[1]+ Terminated sleep 100