Path: utzoo!attcan!uunet!mcsun!ukc!keele!nott-cs!piaggio!anw
From: anw@maths.nott.ac.uk (Dr A. N. Walker)
Newsgroups: comp.unix.questions
Subject: Re: Which script (was Re: comp.unix.questions)
Message-ID: <1990Sep13.151130.10215@maths.nott.ac.uk>
Date: 13 Sep 90 15:11:30 GMT
References: <1990Sep7.152354.9439@ecn.purdue.edu> <563@DIALix.UUCP>
Reply-To: anw@maths.nott.ac.uk (Dr A. N. Walker)
Organization: Maths Dept., Nott'm Univ., UK.
Lines: 24

In article <563@DIALix.UUCP> bernie@DIALix.oz.au (Bernd Felsche) writes:
>In article <1990Sep7.152354.9439@ecn.purdue.edu> patkar@helium.ecn.purdue.edu
(The Silent Dodo) writes:
>>[...] How can a shell script
>>(sh or csh) find out [the directory of] its own file name?
> [gives shell script to parse the PATH]

	Just to point out that any such script is easily spoofed, in case
this is a security- or accounting-related problem.  Try something like

	$ PATH=/something/innocuous export PATH
	$ /bin/sh
	$ PATH=/secret/directory	# note, no export
	$ spoof

and "spoof" will look for itself in "/something/innocuous", even though it
was found in "/secret/directory".  At least, it does in SunOS 4.0.3, and it
does with our somewhat modded SysV shell, though I don't remember seeing
anywhere a definition of what *should* happen if an exported variable is
masked by an unexported one.

-- 
Andy Walker, Maths Dept., Nott'm Univ., UK.
anw@maths.nott.ac.uk