With set -e, is it possible to ignore errors for certain commands? [duplicate]

Question

I have a bash script that I want to globally enable set -e.

But rather than disable it and reenable it all the time, I'm wondering if there is a way of selectively disabling error handling just sometimes. For example, commands run from systemd can be preceeded by a minus to ignore errors. Does bash has an equivalent?

e.g.

#!/bin/bash

set -e

WAN_IF=eth2

# Ignore error on next line
tc qdisc del dev ${WAN_IF} root

# I want errors to stop the script on this line
tc qdisc add dev ${WAN_IF} root handle 1: htb default 10

...
etc

Because of the need to enable/disable a lot I don't want to have to keep doing the following:

set +e
tc qdisc del dev ${WAN_IF} root

# I want errors to stop the script on this line
set -e
tc qdisc add dev ${WAN_IF} root handle 1: htb default 10
...

Answer 1

Add || : (or anything else that is guaranteed not to fail but that's the simplest) to the end of the command.

Though many people would simply tell you that set -e isn't worth it because it isn't as useful as you might think (and causes issues like this) and manual error checking is a better policy.

(I'm not in that camp yet though the more I run into issues like this the more I think I might get there one day.)

From thatotherguy's comment explaining one of major the issues with set -e:

The problem with set -e isn't that you have to be careful about which commands you want to allow to fail. The problem is that it doesn't compose. If someone else reads this post and uses source yourfile || : to source this script while allowing failure, suddenly yourfile will no longer stop on errors anywhere. Not even on failing lines after an explicit set -e.