rick@digibd.com (Rick Richardson) (05/29/91)
I recently posted the enclosed script which demonstrates a
bug in SVR4's Bourne shell. With the help of the net,
it appears that the bug is not restricted to just one
architecture. Failure has been reported on:
AT&T SVR4 on i386
HCI SVR4 on i386
Commodore SVR4 on Amiga
SVR4 on i860
-Rick
#
# 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@digibd.com
Senior MTS Fax: (612) 943-0803
DigiBoard, Inc. Tel: (612) 943-5383slootman@dri.nl (Paul Slootman) (05/30/91)
rick@digibd.com (Rick Richardson) writes: >I recently posted the enclosed script which demonstrates a >bug in SVR4's Bourne shell. With the help of the net, >it appears that the bug is not restricted to just one >architecture. ... [deleted] I just tried it on an ICL DRS6000 (Sparc) running SVR4 (uname -a output: 'drs6000_V_4 dri6000 4.0 2.13 DRS 6000 Sparc'). No problems detected using /bin/sh, /bin/jsh, or /bin/ksh. Paul. -- ---------------- :slootman@dri.nl : When you get to the point where you think that nothing :+ 31 5496 88831 : is impossible, try pushing toothpaste back into a tube ----------------
urban@cbnewsl.att.com (john.urban) (05/30/91)
In article <1991May29.162012.25888@digibd.com> rick@digibd.com (Rick Richardson) writes: >I recently posted the enclosed script which demonstrates a >bug in SVR4's Bourne shell. With the help of the net, >it appears that the bug is not restricted to just one >architecture. Failure has been reported on: > I thought I had replied to you before, but perhaps I forgot or it got lost. This BUG does NOT exist on: AT&T UNIX System V/386 Release 4.0 Version 2.1. Both KSH and SH work fine on the example. 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