text: #include <unistd.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  
  int main() {
      char c;
      int in, out;
      in = open("file.in", O_RDONLY);
      out = open("file.out", O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
  
      while (read(in, &c, 1) == 1) {
          write(out, &c, 1);
      }
  
      exit(0);
  }
  
  