C Program to display Prime Numbers between two numbers

Problem

Write a program in C to display all the prime numbers between a range of 2 numbers.

How to display prime numbers between a range of 2 numbers in C ?

#include <stdio.h>
int main()
{
    int lowerlimit, upperlimit, index, flag;
    
    printf("Abundantcode.com coding sample\n");
    
    printf("Enter Lower limit :");
    scanf("%d", &lowerlimit);
    
    printf("Enter Upper limit :");
    scanf("%d", &upperlimit);


    printf("Prime numbers between %d and %d : ", lowerlimit, upperlimit);

    while (lowerlimit < upperlimit)
    {
        flag = 0;

        for(index = 2; index <= lowerlimit/2; ++index)
        {
            if(lowerlimit % index == 0)
            {
                flag = 1;
                break;
            }
        }

        if (flag == 0)
            printf("%d ", lowerlimit);

        ++lowerlimit;
    }

    return 0;
}

Output

Abundantcode.com coding sample  
Enter Lower limit :5

Enter Upper limit :20      
Prime numbers between 5 and 20 : 5 7 11 13 17 19

%d