[Gllug] Bizarre shell behaviour

[Tethys]

Take the following shell script. Run it:

	#!/bin/sh

	count=0
	while read var
	do
		count=1
	done < /etc/group

	echo $count

Assuming /etc/group isn't empty (which it isn't), the script should
echo 1, right? Well the answer is, it depends on the shell. Under
bash, pdksh and genuine ksh, yes, it does. But under Bourne shell,
it varies. Under AIX and OpenBSD, sure enough it echoes a 1. But
under Solaris and Tru64, it echoes 0 instead.

It's related to the "< /etc/group". If you remove that, and externally
pipe the contents into the script, it works.

Bizarre... any ideas why? Judicious use of debugging echo statements
shows that count is indeed being set to 1 inside the loop, but is being
reset to 0 when the loop exits.

Tet

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