Endless Loop in C while making Fibonacci Sequence with fork()

Question

I am a beginner programmer in C and have been trying to program a Fibonacci sequence sequence in C that reads a command line argument and uses a fork command to output the results. However whenever I run it my program gets stuck in an infinite loop and I have no idea what is causing the issue in the While loop. I haven't been able to use an IDE for this so I apologize for the rough formatting.

int main(int argc, char* argv[])
{
    pid_t id;
    int x = 0;
    int y = 1;
    int fib = 0;
    long input = 0;



    input = (long)argv[1];

    id = fork();

    if(input < 0){
        printf("Enter a positive number. Invalid input");
    }

    if(id == 0){ /*Child Process */
       printf("The numbers in your Fib sequence are: 0, 1, ");
       while(input > 0){
          fib = x + y;
          printf("%d", fib);
          x = y;
          y = fib;
          input = input -1;
       }
       return 1;
    }
    else{ /*parent*/
       wait(NULL);
       printf("Parent is done");
    }
    return 0;
  }

Answer 1

this is wrong

input = (long)argv[1];

argv[1] is a string. You have forced a pointer into being a long and so have ended up with a huge number.

You need strtol, see https://man7.org/linux/man-pages/man3/strtol.3.html

Test argc first to be sure argc > 1