#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>  //errno -l
 
int main(int argc, char *argv[]){
    
    //hard code "data.txt"
    int fd = open("data.txt", O_RDONLY);
    //printf("%d\n", fd);
    if (fd < 0) {
        //fprintf(stderr, "Could not open file (code %d)\n", errno);
        perror("Open");
        return 1;
    }
    char c;
    read(fd, &c, 1);
    printf("%c\n", c);
    close(fd);
    return 0;
}