@lemay @b0rk @nelson The case where you used to need to do this is if you first run a command from the shell, then you change the PATH so that the same command is found in a different place, but it still exists in the original place. bash consults the hash table first. If it says that foo is found in /usr/bin/foo, then you change PATH to put /home/b0rk/bin first, and there's a foo in that directory, bash would still run /usr/bin/foo unless you reset the hash.

But I just tried this and it now appears that the hash table is cleared if PATH is changed. So I think hash -r is no longer needed.

@lemay @b0rk @nelson I take that back. There's a way to produce the issue, just confirmed.

If the PATH is not changed, you've run a command where bash found your program in, say, the 3rd directory, then you add a command of the same name in an earlier directory, bash will run the wrong command unless you do hash -r .