Date: Mon, 31 Oct 94 07:58:13 -0500
From: dj AT stealth DOT ctron DOT com (DJ Delorie)
To: peter AT deakin DOT edu DOT au
Cc: tony AT nt DOT tuwien DOT ac DOT at, djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: strcat() ? 

> The C library string functions have an unstated precondition that string 
> pointers are not NULL. It is up to the user to ensure this. strcat() will not 
> test your arguments.

My ansi reference (not quite the official one, but a summary reference) states:

"If an argument to a library function has a pointer type, then the
value of the argument expression must be a valid address for a data
object of its type.  This is true even if the library function has no
need to access a data object by using the pointer argument."

The example they give includes this line:

	strcpy(s1, NULL)	is INVALID