Joerg Klemenz writes:

> Unless performance is critical, I would rather take the "pretty"
> version, but you are right, of course.

of course... although imho the "pretty" version is using builtins ;)

> Here is what I just did:

> 
> $ time echo $0|grep -q ksh
>     0.03s real     0.00s user     0.00s system
> $ time case $0 in *ksh) echo ksh ;; esac 
> ksh
>     0.01s real     0.01s user 42949672.95s system
>
> (System: 100MHz Intel Pentium)

That system's a speed monster compared to some boxes that NetBSD
runs on! :)  Just for your amusement, as a pointless contribution to
that idle discussion, here're the times on a VAXstation 3100/m30
(~11MHz KA42 CVAX @90ns CPU):

$ time echo $0|grep -q ksh
    0.51s real     0.19s user     0.21s system
$ time case $0 in *ksh) echo ksh ;; esac
ksh
    0.00s real     0.00s user     0.00s system

0.5s isn't much but if you have, say, 10 checks in your profile,
it would mean that you have another 5 seconds to wait until your
prompt shows up (it already takes a couple seconds for the stty
and the tset commands I have in it).
Of course none of that matters on halfway recent hardware.

-- 
Matthias Buelow, mkb(at)informatik.uni-wuerzburg.de