Re: strange --version issue

Gary V. Vaughan wrote:
> Probably your shell has cached the location of the previously 
> installed M4.  Run
> 'hash -r' or equivalent at the command line to make it actually look 
> in the path
> again.
Thanks Gary, this was indeed the problem.

BTW, what's the purpose of "hash"? I read the help on it, but it only 
explains how to use it, not what its rationale is. Clearly it's a 
command cache, but does looking in the search path for an executable 
take so much more time that a location cache was warranted in the shell?

Thanks again,
John