C/Console/Console Menu

Console menu: calculation

<source lang="cpp">

1. include <stdlib.h>
2. include <stdio.h>
3. include <string.h>

int main(void) {

 char command[80], temp[80];
 int i, j;
 for( ; ; ) {
   printf("Operation: add, subtract, divide and multiply? \n");
   
   printf("Enter the whole word \n");
   gets(command);
   /* if user wants to stop */
   if(!strcmp(command, "quit")) 
       break;
   printf("Enter the first number: ");
   gets(temp);
   i = atoi(temp);
   printf("Enter the second number: ");
   gets(temp);
   j = atoi(temp);
   /*  now, perform the operation */
   if(!strcmp(command, "add"))
     printf("%d\n", i + j);
   else if(!strcmp(command, "subtract")) 
     printf("%d\n", i - j);
   else if(!strcmp(command, "divide")) {
     if(j)/* non - zero*/ 
         printf("%d\n", i / j);
   }
   else if(!strcmp(command, "multiply"))
     printf("%d\n", i * j);
   else 
     printf("Unknown command. \n");
 }
 return 0;

}

      </source>