Exit a Script On Error

bash exit shell
Nathan Campos picture Nathan Campos · Dec 7, 2010 · Viewed 185.8k times · Source

I'm building a Shell Script that has a if function like this one:

if jarsigner -verbose -keystore $keyst -keystore $pass $jar_file $kalias
then
    echo $jar_file signed sucessfully
else
    echo ERROR: Failed to sign $jar_file. Please recheck the variables
fi

...

I want the execution of the script to finish after displaying the error message. How I can do this?

Answer

Gilles 'SO- stop being evil' picture Gilles 'SO- stop being evil' · Dec 7, 2010

If you put set -e in a script, the script will terminate as soon as any command inside it fails (i.e. as soon as any command returns a nonzero status). This doesn't let you write your own message, but often the failing command's own messages are enough.

The advantage of this approach is that it's automatic: you don't run the risk of forgetting to deal with an error case.

Commands whose status is tested by a conditional (such as if, && or ||) do not terminate the script (otherwise the conditional would be pointless). An idiom for the occasional command whose failure doesn't matter is command-that-may-fail || true. You can also turn set -e off for a part of the script with set +e.

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