Store a char pointer from terminal input in C -

i'm trying create simple calculator input terminal. supposed work this:

./main.c 1 + 3 1 + 3 = 4 

it simple code per se, have problem terminal input. have read lot here @ stackexchange terminal input error while compiling:

error: assignment incompatible pointer type [-werror=incompatible-pointer-types] 

i not know why. have tried lot of different ways not work. here code, want know how store 1, + , 3 in example above. code post here example how can store "difficult" operation, in case + operator.

#include<stdio.h>  int main(int argc, char *argv[])   {      char operator;     int *operatorp;     operatorp = &operator;      operatorp = argv[2];      printf("%c\n",operator);      return 0;  } 

it not correct, trying convert int * char.

just

#include <stdio.h> #include <stdlib.h> #include <string.h>  int main(int argc, char **argv) {   int nbr1 = atoi(argv[1]);   char operator = argv[2][0];   int nbr2 = atoi(argv[3]);    int result = 0;    if (operator == '+')     result = nbr1 + nbr2;   printf("%d\n", result); }