Subject: Possible bug in md5sum, sha1 and sha2 checksum utilities

From: [email-masked]
Date: Fri, 18 Oct 2013 14:48:39 +0100

Hi,
   First, I hope this isn't some strange manifestation of shell
backslash escaping that has fooled me. I've fiddled around trying to
eliminate that possibility, but it could still happen. Apologies if it is...

Anyway, what I think might be a bug is as follows:

If you use any of md5sum, sha1sum, sha224sum, sha256sum, sha384sum or
sha512sum (are there any others?) on a file whose name contains a
backslash, then the output is prefixed with what appears to be an
erroneous backslash.

I'm using version 7.1 of these GNU coreutils commands. The problem was
also present in version 6.9.

To demonstrate the problem, do the following at a shell prompt >>> :

# Create empty file with backslash in its name.
>>> touch 'jun\k'

# Checksum it.
>>> sha1sum 'jun\k'
\da39a3ee5e6b4b0d3255bfef95601890afd80709  jun\\k

# Checksum it via stdin.
>>> sha1sum <'jun\k'
da39a3ee5e6b4b0d3255bfef95601890afd80709  -

In case the backslashes don't make it through the email system, the file
has a single backslash in its name. The first checksum starts with a
backslash. The second doesn't. I think both outputs should be the same.

Redirecting the output to a file makes no difference, so I don't think
it's a terminal issue.

Regards,

Rodney Warren-Smith