exit

Success

$ exit

Prefer being explicit:

$ exit 0

Error

Use any non-zero positive integer. Typically 1.

$ exit 1

Subshells

Using this bare in the CLI will exit the current terminal. If running inside a script and running the shell script, the script will exit.

$ exit 0

If you use brackets, then that is the exit code for subshell only. It doesn’t exit the entire terminal or program.

$ (exit 0)
$ echo $?
0

$ (exit 1)
$ echo $?
1

Chaining

Some basic chaining.

Note how success allows the st part to run.

$ (exit 0) && echo 'world'
hello

Here we prevent the last part from running so get no output.

$ (exit 1) && echo 'world'

Adding the first command inside the brackets, where you might do a test before exiting.

$ (echo 'hello' && exit 1) && echo 'world'
hello

Without brackets, the 3rd part won’t run.

$ echo "hello" && exit 1 && echo 'world'
hello

Here the exit does nothing because we use ; to ignore it, rather than && for AND.

$ (echo "hello" && exit 1) ; echo 'world'
hello
world

Conditional logic

You can use an if statement to print the help message and actually exit, which is expressive.

RESULT=$(some-task)
if [[ -z $RESULT ]]; then
  echo 'Output is empty'
  exit 1
fi
echo "Next step"

Warning

Be careful of these.

This will always run the last bit, which is not useful.

true || echo "Your command failed" ; exit 1
echo "Next step"

And using brackets will not exist the entire script.

true || (echo "Your command failed" ; exit 1)
echo "Next step"