How to generate a random int in C?

Question

Is there a function to generate a random int number in C? Or will I have to use a third party library?

Answer 1

Note: Don't use rand() for security. If you need a cryptographically secure number, see this answer instead.

#include <time.h> #include <stdlib.h>  srand(time(NULL));   // Initialization, should only be called once. int r = rand();      // Returns a pseudo-random integer between 0 and RAND_MAX. 

On Linux, you might prefer to use random and srandom.