How to detect if a script in Julia got "Killed"?

Question

So I'm running a Julia (v 0.6.3) script in a bash script called ./run.sh like so:

./julia/bin/julia  scripts/my_script.jl

Now the script prematurely terminates. I'm sure of this because it doesn't finish outputting all the data it's supposed to. When I run a parsing script (written in Python) afterwards, it fails because of missing data.

I think that it terminates to insufficient RAM allocation (I'm running the script on a Docker container). If I bump up the allocated RAM the script works fine.

To catch this error in my Julia script I did the following:

try main();
catch e
    println(e)
    exit(1)
end

exit(0)

On top of that, I updated the bash script to check if the Julia script failed:

./julia/bin/julia  scripts/my_script.jl

echo "Julia script returned: $?"

if [ $? -ne 0 ]; then
    echo "Julia script failed"
    exit 1
fi

However, no exception is printed from the Julia script. Furthermore, the return code is 0, so the bash bash script doesn't detect any errors either.

If I just run the the script directly from the terminal, at the very end of the output there's the word Killed. Immediately after I ran the command echo $? and I get 137, which is definitely not a successful return status. So it seems Julia and bash both know the script is terminated, but not if I run the Julia script from within a bash script...?

Another weird thing is when I run the Julia script from the bash script, the word Killed doesn't appear at all!

How can I reliably detect whether a script was prematurely terminated? Is there a way to get the reason it was killed as well (e.g. not enough RAM, stack overflow, etc)?

[ $? -ne 0 ]: $? contains return code of last command. Here from echo and not from julia. — Cyrus

GoinOff GoinOff · Accepted Answer · 2019-08-22T20:34:53

Your code if [ $? -ne 0 ]; then checks if the echo before it successfully completed (See Cyrus's comment).

Sometimes it makes sense to put the return value in a variable:

./julia/bin/julia  scripts/my_script.jl
retval=$?

if [ $retval -ne 0 ]; then
  echo "Julia script failed with $retval"
  exit $retval
fi

How to detect if a script in Julia got "Killed"?

2 Answers