while read do makes bash forget

In article <slrn7v68gp.1n7.ktho0999@dhiurzm31.rz.uni-hildesheim.de>,
Klaus Peter Thorn <ktho0999@rz.uni-hildesheim.de> wrote:
>Barry Margolin wrote:
>> The body of a while loop is executed in a subshell, so all its variable
>> assignments are lost when the subshell exits.

I think Barry meant to say "body of the while loop" (i.e. the one in
your example).

>I guess that the differnce to the   while read do   example
>has something to do with read and pipes. For the sake of comparison:

Correct.  It can get quite confusing to work out whether particular
shell statements will be executed in the main shell process or a sub
process.  Generally, anything that's in a pipeline will be in a sub
process.

Tim.
--
Tim Goodwin   | "[ `static' ] is so overloaded in the C/C++ world that
Leicester, UK | I try to avoid it whenever I can't." -- Larry Wall

Original headers:

From: tjg@star.le.ac.uk (Tim Goodwin)
Newsgroups: comp.unix.shell
Subject: Re: while read do  makes bash forget
Date: 30 Sep 1999 13:59:16 +0100
Organization: University of Leicester, UK
Message-ID: <7svmrq$60k$1@ltpcg.star.le.ac.uk>
References: <slrn7v56ub.qdo.ktho0999@dhiurzm31.rz.uni-hildesheim.de>
  <ZHxI3.331$854.11481@burlma1-snr2>
  <slrn7v68gp.1n7.ktho0999@dhiurzm31.rz.uni-hildesheim.de>