Catching error codes in a shell pipe

Question

I currently have a script that does something like

./a | ./b | ./c

I want to modify it so that if any of a, b or c exit with an error code I print an error message and stop instead of piping bad output forward.

What would be the simplest/cleanest way to do so?

Answer 1

In bash you can use set -e and set -o pipefail at the beginning of your file. A subsequent command ./a | ./b | ./c will fail when any of the three scripts fails. The return code will be the return code of the first failed script.

Note that pipefail isn't available in standard sh.