[DRMAA-WG] C binding -- string lengths

[Piotr Domagalski]

On Thu, Oct 23, 2008 at 7:49 PM, Roger Brobst <rogerb at cadence.com> wrote:
>> So if error_diag_len is supposed to mean size of the
>> string buffer why sizeof(buf) is not used?
>> Shouldn't it be called error_diag_size to be less confusing?
>
> Yes, *IF* the intent was to accept the buffer size, then
> the variable error_diag_size would be a better choice.
> Since that's not the intent, it wasn't chosen.

I was just wondering why the buffer size concept was not chosen. I
think it's a lot simpler and less error-prone.

But OK, I understand that the intent was to accept maximum string
length. Now let's get back to the example:

char buf[DRMAA_ERROR_STRING_BUFFER];
drmaa_init(NULL, buf, sizeof(buf) - 1);

How would you implement the string copying in drmaa_init()? One would
probably use the following code:

int
drmaa_init(..., char *err_diag, size_t err_diag_len)
{
  strncpy(err_diag, SRC, err_diag_len)
}

Now what happens if strlen(SRC) >= sizeof(buf) - 1? Who is responsible
for adding the terminating '\0'?

-- 
Piotr Domagalski