On 08.02.2014 16:10, Tony Houghton wrote:
On Sat, 08 Feb 2014 15:17:09 +0100 Klaus Schmidinger Klaus.Schmidinger@tvdr.de wrote:
On 08.02.2014 14:34, Tony Houghton wrote:
The warning is justified, because if rid is 0 it's still there as an argument, but just happens to have a value of 0. I think you can make snprintf "consume" it without printing anything by adding %.d to the second format string.
I'm afraid not. If I run
#include <stdio.h> int main(void) { for (int n = 0; n < 2; n++) printf(n ? "'%d-%d'\n" : "'%d%.d'\n", 1, 2); return 0; }
I get
'12' '1-2'
But maybe there *is* such a format character, it just isn't "%.d".
You're right, it looks like it has to be %.s, it doesn't work with %.d. If you used %.s you'd probably just get a type mismatch warning instead :-(. There's nothing wrong with the way you wrote it, but I like to enable all possible warnings and eliminate them. In this case I think I'd just print the rid even if it's 0.
The thing is that I'd rather get rid of the RID altogether at some point, so I wouldn't want to manifest it by printing it if it is 0 ;-).
Can you suggest a different way of causing a segfault at this point?
You could add volatile as the warning suggests. Is there a good reason not to use abort() instead?
The idea behind this was to allow for easy backtracking in such a case. I believe abort() wouldn't allow this, would it?
abort() does usually generate a useful core dump/stack backtrace IME.
You're right, I've changed it.
Klaus