CODEWITHSUNDEEP
bashshelltimeout
adamkgray
adamkgray

Reputation: 1947

bash exit 0 on timeout, exit non-0 on failure

I want to run a script with the timeout command and exit 0 if the script runs with no problem or the timeout occurs. Otherwise, if the script exits with some non-0 code, I want to preserve that.

My imaginary syntax would be that timeout implements something like --exit so I can write timeout --exit 0 10s ping google.com.

I have seen this other answer on SO, which says you can handle the exit code of timeout with an or condition, like timeout 10s ping google.com || [[ $? -eq 143 ]]. But that is hard coding the result of timeout, and if my script fails and throws a 143, it will fail silently. I also don't want to force exit 0. If the script fails I want to know.

I am looking for an answer that preserves all failures (and non-failures) from the script, but always exits 0 from timeout. If there is a workaround that doesn't use timeout with a low cognitive complexity I will consider that as well.

Upvotes: 1

Views: 1492

Answers (1)

iforapsy
iforapsy

Reputation: 302

Run the timeout command, and save its exit code to a variable. Compare that against 124, which is the code when the command times out. If the code was 124, we'll exit with 0 to convert the failing exit code into success. If the exit code was not 124, we have the original command's status because timeout exits with that when the command ran to completion.

timeout 10s COMMAND
status="$?"
if (( status == 124 )); then
    # Command timed out
    exit 0
fi
# Command either succeeded or failed
exit "$status"

The one gotcha is when the original command exits with 124 as timeout will propagate that exit code too. To this code, it will look like the command timed out so it will exit with 0 when it should be exiting with nonzero as the original command failed. There is no (easy) way to differentiate the two situations.

Upvotes: 4

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