[PATCH] weston-launch: Fixed TTY switching

[Bill Spitzak]

On 04/07/2015 05:03 PM, Bryce Harrington wrote:

> I'm sure this is not going to ever be a problem since tty filenames and
> paths are on the short side, but since the tty string is an input
> parameter to this routine, it would be better defensive programming to
> use strncpy.

strncpy is not a fix and should never be used.

That is because the proper invocation is:

	strncpy(dest, len-1, src); dest[len-1] = 0;

This is almost always done incorrectly, and even when correct it is hard 
to read and it wastes time filling the buffer with 0 when only the first 
0 needs to be written.

The best solution is to use strlcpy.

If politics make that impossible, use snprintf(dest, len, "%s", src) 
which is exactly the same as strlcpy, including the return value! 
(imagine that...)