From:	Erik Max Francis <max AT alcyone DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: char **argv vs. char *argv[]
Date:	Wed, 11 Jun 1997 08:27:18 -0700
Organization:	Alcyone Systems
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Message-ID:	<339EC3D6.6B9A09B9@alcyone.com>
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To:	djgpp AT delorie DOT com
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Andrea Glorioso wrote:

> I guess they mean exactly the same, because declaring a variable int a[]
> is pretty equal to declaring int ** a.

Be careful about this; pointers and arrays are _not_ the same.  They can
be manipulated in a few different ways, but they are _not_ identical.

> I've seen char * argv[] and
> char** argv being used many times without problems. I think they are
> also compiled in the same way, but maybe you should try to compile to
> assembly code to figure it out.

. . . except in the case of function arguments.  A function with an
argument of a single-dimensioned array is treated in all ways identically
to a pointer.  That is, a function with prototype 

    f(int ai[]);

is treated precisely the same as one with prototype 

    f(int *ai);

Since main is just another function, this applies to it as well.  Either
char **argv (pointer to pointer to char) or char *argv[] (array of pointer
to char) are both treated the same, and so both are legal.  (Note that
char (*argv)[], or pointer to array of char, would be illegal.)

-- 
       Erik Max Francis, &tSftDotIotE / email / max AT alcyone DOT com
                     Alcyone Systems /   web / http://www.alcyone.com/max/
San Jose, California, United States /  icbm / 37 20 07 N  121 53 38 W
                                   \
     "Covenants without the sword / are but words."
                                 / Camden

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