CommandLine in C Programming

#include<Stdio.h>

#include<string.h>

#include<stdlib.h>

int main(int argc, char *argv[])

{

    char *operator;

    int a,b;

    operation = argv[1];

    a = atoi(argv[2]);

    b = atoi(argv[3]);

    if(strcmp(operation, "add")==0)

    {

        printf("%d",a+b);

    }

         else if(strcmp(operation, "sub")==0)

    {

        printf("%d",a-b);

    }

        else if(strcmp(operation, "mul")==0)

    {

        printf("%d",a*b);

    }  

        else if(strcmp(operation, "div")==0)

    {

        printf("%d",a/b);

    }

    return 0;

}