greater_check.c Code: #include<stdio.h> #define EQUAL_ERROR 0 //This function inputs 2 numbers and returns the greater one.. // Returns zero if the numbers are equal int max(no1,no2) { if(no1 > no2) { return(no1); } else if(no1 < no2) { return(no2); } else { return(0); // If the no's are equal } } int main() { int no1 = 0 , no2 = 0; // Declare and initialise integers int greater = 0; // The holder of the greater no printf("Please enter 2 numbers seperated by a [space] and the program will tell you which one is greater :- \n"); scanf("%d %d",&no1,&no2); greater = max(no1,no2); // ERROR CHECKING // Check for errors if(greater == EQUAL_ERROR) { printf("The numbers input are equal\n"); return(-1); } // else we are clean print the outut else { printf("%d is greater\n",greater); } return(0); } Compiling :- Code: gcc greater_check.c -o greater_check