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Date: Tue, 5 Jun 2012 12:37:59 -0500 (CDT)
From: Robert Bonomi <bonomi@mail.r-bonomi.com>
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To: tundra@tundraware.com
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Cc: freebsd-questions@freebsd.org
Subject: Re: Possible /bin/sh Bug?
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> From: Tim Daneliuk <tundra@tundraware.com>
>
> Given this script:
> #!/bin/sh
>
> foo=""
> while read line
> do
>    foo="$foo -e"
> done
> echo $foo
>
> Say I respond 3 times, I'd expect to see:
>
> -e -e -e
>
> Instead, I get:
>
> -e -e
>
> Linux appears to do the right thing here, so this seems like it
> is a bug ... or am I missing something?

Yup.  there are -multiple-, incompatible, standards for 'echo'.
a SYS-V derived echo will behve diferently than  UCB based one.

varous shell-program 'built-in' implementtions may have yet different
behavior.

Recommendation -- use 'print' instead of 'echo', it is much more predictble
in differnt environments.

ALTERNATIVE:  replace the last line of the script with:
   echo -- $foo