Hi there,
I have a problem for which I really like your input.
I have two shell scripts (script_2a.sh and script_2b.sh) that are started by single script: script_1.sh.

Script _1.sh simply looks something like this:

(I send 2a and 2b off to a cluster computer that can run them in parallel, each script takes between 3 and 6 hours to run, I don’t know before hand which one finishes first)

THE PROBLEM:
When both 2a and 2b are done I automatically would like to start running script_3.sh


I’M THINKING THE SOLUTION MIGHT LOOK LIKE THIS:
1.
I could add a line to both 2a and 2b that produces:
/tmp/script_2a_done.dat
/tmp/script_2b_done.dat

2.
I can have script_1.sh (after it has started 2a and 2b) check whether /tmp/script_2a_done.dat and /tmp/script_2b_done.dat have finished after which it starts script_3.sh.


PRACTICAL QUESTIONS:
1.
Does anybody know how I can make a script that can tell if /tmp/script_2a_done.dat AND /tmp/script_2b_done.dat have been written, so I can tell it to start script_3.sh?

2.
Would anyone recommend a different solution?


Thanks a lot!

Mike

There's a "wait" function in bash that's probably what you're looking for. If you specify it with no arguments, it waits until all backgrounded processes have exited before moving on.

Your script would look something like this:


You can also pass a PID to "wait" (I believe), so you try something like this if you're worried about the possibility of there being other processes in the pipeline:

Thanks reickler. You suggestion did the trick. I've used the second option to be sure and it works perfectly!