How to exit if a command failed? [duplicate]

Try:

my_command || { echo 'my_command failed' ; exit 1; }

Four changes:

• Change && to ||
• Use { } in place of ( )
• Introduce ; after exit and
• spaces after { and before }

Since you want to print the message and exit only when the command fails ( exits with non-zero value) you need a || not an &&.

cmd1 && cmd2

will run cmd2 when cmd1 succeeds(exit value 0). Where as

cmd1 || cmd2

will run cmd2 when cmd1 fails(exit value non-zero).

Using ( ) makes the command inside them run in a sub-shell and calling a exit from there causes you to exit the sub-shell and not your original shell, hence execution continues in your original shell.

To overcome this use { }

The last two changes are required by bash.

The other answers have covered the direct question well, but you may also be interested in using set -e. With that, any command that fails (outside of specific contexts like if tests) will cause the script to abort. For certain scripts, it's very useful.

If you want that behavior for all commands in your script, just add

set -e set -o pipefail

at the beginning of the script. This pair of options tell the bash interpreter to exit whenever a command returns with a non-zero exit code. (For more details about why pipefail is needed, see http://petereisentraut.blogspot.com/2010/11/pipefail.html)

This does not allow you to print an exit message, though.