Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!mephisto!ncsuvx!mcnc!unccvax!cs00jmc
From: cs00jmc@unccvax.UUCP (John Covington WN4BBJ)
Newsgroups: comp.sys.ibm.pc.programmer
Subject: Re: redirection indicated in argc
Message-ID: <1835@unccvax.UUCP>
Date: 16 Feb 90 18:07:15 GMT
References: <1022@wubios.wustl.edu>
Reply-To: cs00jmc@unccvax.UUCP (John Covington WN4BBJ)
Organization: University of North Carolina at Charlotte
Lines: 32

In article <1022@wubios.wustl.edu> david@wubios.UUCP (David J. Camp) writes:
>I was using Microsoft C, and had a program that used command line
>arguments and read the standard input.  When I specified:
>
>    command arg1 arg2 ... argn-1 < filename
>
>The argc variable reflected the presence of the filename.  
>i.e. it had the value n+1.
>When I specified:
>
>    type filename | command arg1 arg2 ... argn-1
>
>it was not indicated, i.e. it had the value n.  I think this must 
>be a compiler bug.  -David-
>

Actually, argc does not indicate the presence of filename at all.
In C programs argv[0] is supposed to point to the name of the
program currently being run (in this case command). Thus argc
will always be at least 1.  If arg1 is present then argc = 2, etc.

Filename is never passed to the program because DOS opens the file
and attaches it to stdin.

--John

--
John Covington WN4BBJ        E-mail: cs00jmc@unccvax.uncc.edu
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