Subject: Re: /etc/login.conf required to exist after user(8) changes
To: Christos Zoulas <>
From: Denis Lagno <>
List: current-users
Date: 07/30/2005 19:01:28
On Fri, Jul 29, 2005 at 02:12:46PM -0400, Christos Zoulas scribed:
> It is used, but not de-referenced so it is not a problem. I.e. the value
> at the end of the pointer is freed, but we are only checking if there
> was a value.

well, it works but as far as the C standard is concerned it is wrong.

Subsection "Memory management functions" says:

The  value  of  a  pointer that refers to freed space is indeterminate.

And section about undefined behaviour says:

undefined behavior:
behavior, upon use of <blah-blah-blah> or of indeterminately valued
objects ...

No derefernce required for undefined behaviour, use suffies.