Arguments and type casting

I wanted to start learning C, and I just got to arguments and they are pretty useful and I decided to write a celsius to fahtrenheit program that took the celsius degree as an arg and typecast it to type long so I could do the calculation. I don't know what's wrong, but I always get a really big negative number. Here is the code:

Code:

1:      /**************************************
2:       * cels2fahr.c:
3:       * A program that takes an integer as an argument
4:       * and converts it from Celsius (C) to Fahrenheit
5:       * (F).
6:       ************************************/
7:
8:      #include <stdio.h>
9:
10:     int main(int argc, char *argv[]) {
11:
12:             int fahr = 0;
13:
14:             if (argc < 2) {
15:                     printf("Proper Usage: \n");
16:                     printf("cels2fahr <DEGREES IN CELSIUS>\n\n");
17:                     return 1;
18:             }
19:
20:             fahr = (9.0/5.0) * (long) argv[1] + 32;
21:
22:             printf("%d\n", fahr);
23:
24:             return 0;
25:     }

Arguments are charactor arrays, you can't just type cast them and have them changed to a numeric representation for you. There is the atoi function that accepts a char pointer and returns it's numeric value.

Did you actually try to compile the code with the line numbers in? That won't work.

atoi() . . . sscanf() is better. See the FAQ.

No, I wrote a program that lists it out like that for me and I copied/pasted it onto here. Ok, so I need to use atoi()? I will get right on that.