Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!ucbvax!STC06.CTD.ORNL.GOV!de5
From: de5@STC06.CTD.ORNL.GOV (SILL D E)
Newsgroups: comp.unix.questions
Subject: Bourne shell oddity
Message-ID: <9008071535.AA01487@stc06.CTD.ORNL.GOV>
Date: 7 Aug 90 15:35:07 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: de5@ornl.gov
Organization: Oak Ridge National Lab
Lines: 43

What should the following script do?

#!/bin/sh
foo=bar
while true
do
    if [ $foo = bar ]
    then
        foo=baz
        echo foo=${foo}
        break
    fi
done </dev/null
echo foo=${foo}

I would have expected it to output:

foo=baz
foo=baz

But I get:

foo=baz
foo=bar

Removing the input redirection from the while-loop gives the expected
result. 

Question:  Is this a bug, or is I/O redirection of commands supposed
to affect variable scoping somehow?  I couldn't find anything in the
FM to explain this behavior.

Another Question:  Is there a simple workaround, preferably something
more elegant than passing values in files?

Please reply by mail; I don't follow this group/list.

Thanks.

--
Dave Sill (de5@ornl.gov)
Martin Marietta Energy Systems
Workstation Support