TIL: timeout in Bash scripts

Reading time: 2 minutes The other day at work we had a Bash script that would set up a web server and wait for it to be up before proceeding to the next things. The script worked fine and we had no issues, until we had an infinite loop. We were using the Bash built-in until to check if the web server was up: until curl --silent --fail-with-body 10.0.0.1:8080/health; do sleep 1 done This works fine. Unless our web server crashes during startup and we sleep 1 forever. Here comes a handy utility: timeout . As the name suggests, this command adds a timeout to other commands. You specify the time limit you want to wait for a command and if that time passes, timeout sends a signal to terminate it and exits with non-zero. By default, timeout sends SIGTERM , but you can change it with the --signal flag, e.g. timeout --signal=SIGKILL 1s foo . For example, timeout 1s sleep 5 will send the SIGTERM signal to sleep after 1 second: $ time timeout 1s sleep 4 real 0m1,004s user 0m0,000s sys 0m0 ... Read full article.