How to write a logic for detecting a prime number?

Prime numbers are those positive numbers which are only divisible by 1 and the number itself. A simple logic can be written to check this like starting iteration with 2 to (number -1) and inside this we check if number is divisible. If it completes all iterations and found not divisible by any number in the range then it is a prime number.

#define TRUE 1
#define FALSE 0
bool is_prime(unsigned int number)
{
  unsigned int i;
  for (i = 2; i < number; i++)
  {
    if((number%i) ==0) 
      return FALSE;
  }
  return TRUE;
}

Print all prime numbers in a given range


int main(int argc, char* argv[])
{
  unsigned int index;
  unsigned int range;
  printf("Print Prime numbers till #");
  scanf("%u", &range);
  for(index = 1; index <= range; index++)
  {
    if(is_prime(index) != FALSE){
      printf("%u,", index);
    }
  }
  printf("\b.");
  return 0;
}

Output:
Print Prime numbers till #50
1,2,3,5,7,11,13,17,19,23,29,31,37,41,43,47.

Print first n-number of prime numbers


int main(int argc, char* argv[])
{
  unsigned int index;
  unsigned int count;

  printf("\nHow many prime no to print #");
  scanf("%u", &count);
  for(index = 1; count > 0; index++)
  {
    if(is_prime(index) != FALSE){
      printf("%u,", index);
      count--;
    }
  }
  printf("\b.");
  return 0;
}
Output:
How many prime no to print #10
1,2,3,5,7,11,13,17,19,23.

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