bug#4115: grep and null device

[Eli Zaretskii]

> Date: Tue, 11 Aug 2009 09:41:50 +0100 (BST)
> From: ts011c8050@blueyonder.co.uk
> Cc: 
> 
> Using emacs 23.1.1 on Windows ( also saw it on emacs 22.x and upgraded )
> grep is from cygwin "GNU grep 2.5.3"
> 
> 
> Using rgrep always tags on a null device giving lots of output like
> 
> grep: NUL: No such file or directory

Does Cygwin support NUL as the Windows null device?  If not, that's
your problem.

Doesn't `rgrep' also invoke `find'?  (It should show the full command
it is running in the "*grep*" buffer.)  If so, what port of `find' are
you using?