Send KillAll to multiple node process and wait response

I’m creating a script that makes some pull from a git repository.

but first i want to send a SIGUSR1 to multiple nodes that i have running in the machine, and once all the procesess stop i will proceed to git pull

so basicly i will run

killall -s SIGUSR1 node

because my node is doing an infinite loop, i want to intercept this signal and kill in a portion of the loop where i know it won’t affect any data.

So when all the nodes are stopped i will continue

but how do i wait for all the node process exit cleanly before doing the git pull and starting again the node loop

Answer

From man killall:

    -w, --wait
           Wait for all killed processes to die.  killall checks once  per  second  if  any  of  the
           killed  processes  still  exist and only returns if none are left.  Note that killall may
           wait forever if the signal was ignored, had no effect, or if the process stays in  zombie
           state.