SVR4 /bin/sh BUG

[john.urban]

In article <1991May30.034223.29061 at digibd.com> rick at digibd.com (Rick Richardson) writes:
>I'm posting this here in the hopes that the various
>vendors of SVR4 fix this in their next releases.
>Known to fail on AT&T, HCI, Commodore, and i860 SVR4's.

Your program DOES NOT FAIL on AT&T UNIX System V/386 Release 4.0 Version 2.1.
I verified that it works fine with the ksh and the sh.

Sincerely,

John Ben Urban
>
>#
>#	Demonstrates bug in SVR4 /bin/sh
>#	Works OK with /bin/sh on SVR3 and XENIX
>#	Works OK with /bin/ksh on SVR4
>#
>#	Should output the first line of /etc/passwd four times
>#	Only does it three times on SVR4 and then hangs
>#
>#	Seems to be related to changing fd0 in a function
>#
>read_by_func() {
>	exec 3<&0 0<$1
>	read x
>	echo $x
>	exec 0<&3 3<&-
>}
>
>exec 3<&0 0</etc/passwd
>read x
>echo $x
>exec 0<&3 3<&-
>
>exec 3<&0 0</etc/passwd
>read x
>echo $x
>exec 0<&3 3<&-
>
>read_by_func /etc/passwd
>
># Gets stuck here with /bin/sh...
>read_by_func /etc/passwd
>-- 
>Rick Richardson		Email: rick at digibd.com
>Senior MTS		Fax: (612) 943-0803
>DigiBoard, Inc.		Tel: (612) 943-5383