I should have mentioned that 1. I am already using set -e 2. That `err` function has an `exit 1` as its last step, which forces the program to stop runn

I should have mentioned that 1. I am already using set -e 2. That `err` function has an `exit 1` as its last step, which forces the program to stop running when combined with the first point. > Now, on to your shell script example: in practice you'll never see an error because both grep and sed return true even when no matching or substitution is done. That's not what I'm seeing: > echo "hi" | grep "bye" > echo $? 1 I'm typing that into my shell. Thanks for the reply, it was very helpful.