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From: gam@amdahl.UUCP (G A Moffett)
Newsgroups: net.news.adm,net.news.sa,net.sources.d
Subject: Re: Beware of Blindly Un-SHARing a File
Message-ID: <3051@amdahl.UUCP>
Date: Sun, 20-Apr-86 18:35:32 EST
Article-I.D.: amdahl.3051
Posted: Sun Apr 20 18:35:32 1986
Date-Received: Wed, 23-Apr-86 20:56:48 EST
References: <947@kitty.UUCP> <3029@amdahl.UUCP>
Reply-To: gam@amdahl.UUCP (G A Moffett)
Organization: Amdahl Corp, UTS Products Group
Lines: 40
Keywords: sh options
Xref: watmath net.news.adm:621 net.news.sa:279 net.sources.d:138
Summary: "sh -x -v" doesn't work as expected ...

In article <3029@amdahl.UUCP> I said:

> And fortunately, the shell provides a nice way to check what sorts
> of things a shar will do.  For example:
> 
> 	sh -x -n foo.shar
> 
> or more verbosely:
> 
> 	sh -v -n foo.shar

I was mistaken in my suggestion to use these two.  Their effects are
not what I expected them to be:

First of all, the flags must be grouped together.  If the first arg
begins with '-', the shell expects it to contain *all* flags to be
passed to it.  "sh -x -n ..." produces (ultimately) "-n: cannot open".

Secondly, the form "sh -x -n" (properly, "sh -xn") has little effect:
the "-n" overrides what the "-x" option tells it to do, and so nothing
is printed except environment variable assignments.

Thirdly, the last example is equialent to "cat foo.shar".  This is not
so bad as it seems, since you should probably read the shell script
before you run it, if you are suspicious of what it might do ....

This is the behavior of the shell in System V.  I tried this on a V7
(Unisoft) system and it behaved similarly.

Credits: E. Leeper (mtgzz!ecl) and Mark Brader (lsuc!msb) brought these
things to my attention.  The error is mine in not actually *testing*
what I thought would solve the problem.  I will be more cautious in the
future and test my suggestions before dropping them on an unsuspecting
public.
-- 
Gordon A. Moffett		...!{ihnp4,seismo,hplabs}!amdahl!gam

"Life's a bitch and then you die."
--
[ This does not represent Amdahl Corporation ]