#include <stdio.h>

int main(int argc, char *argv[]){ 
    if(argc < 2){
        fprintf(stderr, "Usage %s filename\n", argv[0]);
        return 1;
    }

    FILE *f = fopen(argv[1], "a");
    //int fd = open(argv[1], O_WRONLY | O_CREAT | O_TRUNC, 0666); "w"
    //int fd = open(argv[1], O_WRONLY | O_CREAT | O_APPEND, 0666); "a"
    //printf("fd was %d\n", fd);
    if (f == NULL) {
        fprintf(stderr,"Could not open file %s: ",argv[1]);
        perror("");
        return 1;
    }

    fprintf(f, "potato");
    //write(fd, "potato", 6);

    fclose(f);
    return 0;
}