Nasty bug in release 4 Bourne shell

[Lee Ziegenhals]

andy at xwkg.Icom.Com (Andrew H. Marrinson) writes:
>In the process of porting smail3.1.19 to System V release 4, I found
>a very nasty bug!  If you use exec to redirect output in a while loop
>(as in ``exec >/tmp/foo'', that is an exec with no command), it only
>seems to obey the first such redirection.  I RTFM and it gives me no
>reason to believe this is other than a bug.  (Note: this is Bourne
>shell.  I haven't checked ksh yet.)

I ran into the same problem, doing the same thing you were.  Ksh does not
have the same problem, so I was able to work around it.  Sure threw me for
a while, though...

>I got this result using Dell Unix.  I suspect that it is an AT&T bug,
>though.  I can't imagine Dell fooled with Bourne shell at all.  Let me
>know if there is a release 4 System V out there that doesn't do this!

It happened to me using the SVR4 code straight from AT&T, so it isn't
anything Dell did.