Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!bionet!ames!amdahl!pyramid!leadsv!laic!nova!darin
From: darin@nova.laic.uucp (Darin Johnson)
Newsgroups: comp.sys.amiga
Subject: Re:  Struggling through the "C"
Message-ID: <510@laic.UUCP>
Date: 13 Apr 89 16:55:36 GMT
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Reply-To: darin@nova.UUCP (Darin Johnson)
Organization: Lockheed AI Center, Menlo Park
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As an example of the difference between "char *a", and "char a[100]", here
is a piece of code that bit me recently:

  put_args(xdr_wrapstring, &str)

Where I had assumed str was a "char *", but instead, was really an
array.  The routine needed the ADDRESS of the string pointer, not the
pointer.  As such, the compiler gave me a rude warning - "thou shalt not
take the address of an array!".  This was on UNIX.  I was surprised since
I do this sort of stuff in VMS, where a temporary variable is created
automatically (I can pass variables of the sort "&0", etc.).
The fix was simple:

  register char *sp;
  ... intervening code ...
  sp = str;	/* or instead, s = &str[0] */
  put_args(xdr_wrapstring, &sp);

Of course, if you pass an array or pointer as an argument to a routine,
then inside the routine, you don't have a problem, since you can always
take the address of the parameter - which is on the stack or in a temporary.

Darin Johnson (leadsv!laic!darin@pyramid.pyramid.com)
	Can you "Spot the Looney"?