rand.h

基于挑战—应答模式的客户端认证程序

#define RANDOM_MAX 0x7FFFFFFF

static long my_do_rand(unsigned long *value)

{

/*


   */

   long quotient, remainder, t;

 

   quotient = *value / 127773L;

   remainder = *value % 127773L;

   t = 16807L * remainder - 2836L * quotient;

 

   if (t <= 0)

      t += 0x7FFFFFFFL;

  return ((*value = t) % ((unsigned long)RANDOM_MAX + 1));

}

static unsigned long next = 1;

int my_rand(void)

{

   return my_do_rand(&next);

}

void my_srand(unsigned int seed)

{

   next = seed;

}

#include <time.h>

int main()

{

   int i;

  

   my_srand((unsigned)(time(NULL)));

   for(i=0;i<100;i++)

   {

      if(i % 10 == 0)

         printf("\n");

      printf("%d\t",my_rand());

   }
   return 0;

}