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From: gwyn%brl-vld@sri-unix.UUCP
Newsgroups: net.unix
Subject: Re:  argc[argv] and Berknet
Message-ID: <14434@sri-arpa.UUCP>
Date: Thu, 8-Dec-83 11:44:42 EST
Article-I.D.: sri-arpa.14434
Posted: Thu Dec  8 11:44:42 1983
Date-Received: Tue, 13-Dec-83 01:30:34 EST
Lines: 9

From:      Doug Gwyn (VLD/VMB) <gwyn@brl-vld>

There is no mystery about	argc[argv] = 0;
pre-7th Edition PDP-11 UNIX exec marked the end of the arguments with
a 16-bit constant -1 and newer UNIXes mark the end of the argument list
with a (char *)0.  The run-time start-off looks for this terminator to
determine argc to pass to main().  The above code merely patches a 6th
Edition image so that *argv++ can be easily used to pick up arguments
and test for the last argument.  (Not recommended.)