Message-Id: <200507191622.j6JGM5lW021804@delorie.com>
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Reply-To: <fergus AT bonhard DOT uklinux DOT net>
From: "fergus" <fergus AT bonhard DOT uklinux DOT net>
To: <cygwin AT cygwin DOT com>
Cc: <fergus AT bonhard DOT uklinux DOT net>
Subject: OT: grep for \x00 = NUL
Date: Tue, 19 Jul 2005 17:16:05 +0100
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Sorry, probably off topic but so tantalising and so easily stated I thought
I'd try you. Using grep to locate hex characters in files I've used the
syntax

	grep $'\x0d' # e.g. equivalent to grep "^M"
	grep $'\x1a' # e.g. equivalent to grep "^Z"

and found this to work for all \x01 to \xff, that's 255 of the 256 one might
be interested in looking for. (Well, I haven't tried them all, but a lot of
them.) What I still can't do (actually, what I most wanted to do) is search
for the NUL \x00. Nothing in info bash indicated that this approach would
not work for \x00, but as far as I can tell, it doesn't: files that do not
contain \x00 are listed as containing it (try grep $'\x00' *).

Is it a bug?

Any ideas? (This has cropped up before but sorry I can't seem to find it.
Various suggestions included piping output from od to grep, but this
approach just involving grep seems much more direct if it can be made to
work.)

Fergus


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