Well, the exit codes of both of those commands (despite being different) is actually 7. But 7 does not match either error string, so the power user would have t

Well, the exit codes of both of those commands (despite being different) is actually 7. But 7 does not match either error string, so the power user would have to string search it anyway. eclipse ~ # route add 1234 SIOCADDRT: No such device eclipse ~ # echo $? 7 eclipse ~ # route del 1234 SIOCDELRT: No such process eclipse ~ # echo $? 7 Maybe I used a bad example? I get your point though.