// Postfix calculator
// Adds, subtracts, multiplies, divides, and does modular arithmetic
#include <stdio.h>
int main(int argc, char *argv[]){
int num1, num2, ans;
if(argc != 4){ //quits at invalid arguement #
puts("Usage: calc int int operation.");
return 0;
}
else{
num1 = *argv[1] - '0'; //converts char input to integers
num2 = *argv[2] - '0';
switch(*argv[3]){ //calc operations
case '+':
ans = num1 + num2;
printf("%d\n", ans);
break;
case '-':
ans = num1 - num2;
printf("%d\n", ans);
break;
case 'x':
ans = num1 * num2;
printf("%d\n", ans);
break;
case '/':
ans = num1 / num2;
printf("%d\n", ans);
break;
case '%':
ans = num1 % num2;
printf("%d\n", ans);
break;
default:
puts("Bad operator. Use +, -, x, /, or %");
}
}
return 0;
}