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From: allbery@ncoast.UUCP (Brandon Allbery)
Newsgroups: comp.unix.questions
Subject: Re: Trick question
Message-ID: <4924@ncoast.UUCP>
Date: Thu, 22-Oct-87 17:56:25 EST
Article-I.D.: ncoast.4924
Posted: Thu Oct 22 17:56:25 1987
Date-Received: Sun, 25-Oct-87 14:30:21 EST
References: <666@portofix.liu.se>
Reply-To: allbery@ncoast.UUCP (Brandon Allbery)
Followup-To: comp.unix.questions
Organization: Cleveland Public Access UN*X, Cleveland, Oh
Lines: 22

As quoted from <666@portofix.liu.se> by kjepo@portofix.liu.se (Kjell Post):
+---------------
| A little trick question for you all: what's happening here?
| 
| 	% cat > +
|         date
|         ^D
|         % chmod +x +
|         % +
|         $                         -- entered Bourne-shell
+---------------

Is this on System V with a csh, or a Sun or other BSD system with the System
V sh?  The System V sh treats + like - for setting flags; as a result, when
execvp() does its thing you get

	sh +

which will start an interactive shell.
-- 
Brandon S. Allbery		     necntc!ncoast!allbery@harvard.harvard.edu
  {{harvard,mit-eddie}!necntc,well!hoptoad,sun!mandrill!hal}!ncoast!allbery