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From: simon@its63b.UUCP
Newsgroups: comp.unix.questions,comp.unix.wizards,comp.unix.xenix
Subject: Re: Confused file name in directory
Message-ID: <285@its63b.ed.ac.uk>
Date: Fri, 27-Feb-87 08:36:44 EST
Article-I.D.: its63b.285
Posted: Fri Feb 27 08:36:44 1987
Date-Received: Sat, 7-Mar-87 00:15:43 EST
References: <105@aob.UUCP> <563@aw.sei.cmu.edu.sei.cmu.edu> <5587@mimsy.UUCP>
Reply-To: simon@its63b.ed.ac.uk (ECSC68 S Brown CS)
Organization: I.T. School, Univ. of Edinburgh, U.K.
Lines: 40
Xref: utgpu comp.unix.questions:1269 comp.unix.wizards:1220 comp.unix.xenix:144

In article <5587@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes:
>In article <105@aob.UUCP> someone finds a directory entry with an
>embedded NUL, and has nothing handy to fix it.
>
>There is still another way, easier yet but more dangerous and
>thrilling.  You cannot edit a directory, but you can edit a file.
>And the only difference between the two is one byte.
>
>Write another program, `hacki'.
>Instead of zeroing the inode, toggle the S_IFDIR and S_IFREG bits.
>Run it once on the directory inode, and now it is a file.  Use your
>favourite binary editor (Emacs works, but be sure it does not make
>a backup!), fix the embedded NUL character.  Make sure the file size
>is exactly the same as before.  Then run the hacki program once
>more.
>
>Of course, if you have source, you could alter fsck to check for
>embedded NULs in filenames.

Another "entity" you can edit is a disk - using a nice powerful editor
like adb :-) So, just find the i-number for the directory, then: power-up
your adb, find the inode-entry for the directory, from which you can find the
data-block list (luckily there're hardly ever any indirect blocks in a 
directory, unless its very big), find the bad bytes, and change them to 
something sensible.

Why write new code when you do anything you need using existing utilities :-)

-- 

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Simon Brown                                             @@@\
Department of Computer Science                         /-/@ \
University of Edinburgh, Scotland, UK.                / /@   \@@
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