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From: jim@ism780c.UUCP (Jim Balter)
Newsgroups: comp.sys.amiga
Subject: Re: argv[n][n] doesn't exist
Message-ID: <4801@ism780c.UUCP>
Date: Sat, 6-Dec-86 18:29:24 EST
Article-I.D.: ism780c.4801
Posted: Sat Dec  6 18:29:24 1986
Date-Received: Mon, 8-Dec-86 03:30:24 EST
References: <816@ulowell.UUCP>
Reply-To: jim@ism780c.UUCP (Jim Balter)
Organization: Interactive Systems Corp., Santa Monica, CA
Lines: 44

In article <816@ulowell.UUCP> walton@ametek.UUCP (Steve Walton) writes:
>Bill Mayhew says (and others commiserate):
>>        I just ran into a minor annoyance with the Lattice C compiler
>>that we have here at work.  If memory stikes me right, it's version
>>3.02.
>>
>>I discovered that when I read argv[n][n] that the string isn't always
>>terminated with a \0 as you'd expect.  This seems to happen mostly (if
>>not only) when the string contains ascii characters that are digits.
>
>Ahem...argv is not a two dimensional array, but rather an array of pointers.
>As such, it CANNOT be addressed with two subscripts as argv[n][n].  There
>is a difference, see K&R for details.  The correct way to find the \0 at
>the end of the j'th argument is:
>	char *s;
>	s = argv[j];
>	for (i = 0; s[i] != '\0'; i++);		/* i is now length of arg j */
>If I badly misunderstood Bill's posting and have therefore insulted
>everyone's intelligence, forgive me.
>
>Stephen Walton			ARPA:	ametek!walton@csvax.caltech.edu
>Ametek Computer Research Div.	BITNET:	walton@caltech
>610 N. Santa Anita Ave.		UUCP:	...!ucbvax!sun!megatest!ametek!walton
>Arcadia, CA 91006 USA
>818-445-6811

You are wrong. You did not read or did not understand your C reference
manual, and definitely did not test your claim before stating it as fact.
Please act more resonsibly in the future and avoid insulting your *own*
intelligence.

Given the parameter or extern declarations (for definitions, "[]" is illegal,
and a specific dimension must be given; for declarations, the innermost
dimension can be left unspecified) "char **foo;" or "char *foo[];" or
"char foo[][10];", even though these are represented in memory in three
different ways (only two for parameters; "char **foo;" and "char *foo[];"
are the same in that case, since an array cannot be passed on the stack,
so foo must be a pointer and not a location) the references "foo[n][m]",
"*(foo[n] + m)", and "*(*(foo + n) + m)" are all valid and all produce the
same results.  See K&R for details indeed.

Do not trust in false wizards.
-- 
-- Jim Balter ({sdcrdcf!ism780c,ima}!jim)