This C Program converts the given binary number into decimal. The program reads the binary number, does a modulo operation to get the remainder, multiples the total by base 2 and adds the modulo and repeats the steps.
Here is source code of the C program to covert binary number to decimal. The C program is successfully compiled and run on a Linux system. The program output is also shown below.

/*
* C program to convert the given binary number into decimal
*/
#include <stdio.h>

void main()
{
int num, binary_val, decimal_val = 0, base = 1, rem;

printf("Enter a binary number(1s and 0s) \n");
scanf("%d", &num); /* maximum five digits */
binary_val = num;
while (num > 0)
{
rem = num % 10;
decimal_val = decimal_val + rem * base;
num = num / 10 ;
base = base * 2;
}
printf("The Binary number is = %d \n", binary_val);
printf("Its decimal equivalent is = %d \n", decimal_val);
}

$ cc pgm38.c
$ a.out
Enter a binary number(1s and 0s)
10101001
The Binary number is = 10101001
Its decimal equivalent is = 169S