Bugs in Hello World(blog.sunfishcode.online)

  long result = write(1, "Hello", sizeof("Hello") - 1);

  switch (result) {
    case -EAGAIN:
      /* Occurs only if opened with O_NONBLOCK. */
      break;
    case -EWOULDBLOCK:
      /* Occurs only if opened with O_NONBLOCK. */
      break;
    case -EBADF:       
      /* File descriptor is invalid or wasn't opened for writing. */
      break;
    case -EDQUOT:
      /* User's disk quota reached. */
      break;
    case -EFAULT:
      /* Buffer points outside accessible address space. */
      break;
    case -EFBIG:
      /* Maximum file size reached. */
      break;
    case -EINTR:
      /* Write interrupted by signal before writing. */
      break;
    case -EINVAL:
      /* File descriptor unsuitable for writing. */
      break;
    case -EIO:
      /* General output error. */
      break;
    case -ENOSPC:
      /* No space available on device. */
      break;
    case -EPERM:
      /* File seal prevented the file from being written. */
      break;
    case -EPIPE:
      /* The pipe or socket being written to was closed. */
      break;
  }

  /* Even exiting has subtleties.  On exit, if any writes failed, change
     the exit status.  The /dev/full device on GNU/Linux can be used for
     testing; for instance, hello >/dev/full should exit unsuccessfully.
     This is implemented in the Gnulib module "closeout".  */

    echo header > gen.txt && ./helloworld >> gen.txt && ./upload_to_prod gen.txt

  if (fflush(stdout) != 0 || ferror(stdout) != 0)
  {
    perror("stdout");
    return EXIT_FAILURE;
  }

    puts("Hello, world!");
    puts("message received OK? [y/n]")
    return (fgets(buffer, sizeof buffer, stdin) != NULL && buffer[0] == 'y')
            ? EXIT_SUCCESS : EXIT_FAILURE;

  $ ./hello < /dev/null > /dev/null

  $ yes | ./hello > /dev/null

  internal/fs/utils.js:332
      throw err;
      ^
  Error: ENOSPC: no space left on device, write
      at writeSync (fs.js:736:3)

  #include <stdlib.h>
  #include <unistd.h>
  
  int main(void)
  {
      int status;
      status = write(1, "Hello World!\n", 13);
      if (status < 0)  { return EXIT_FAILURE; }
      return EXIT_SUCCESS;
  }

  #include <stdio.h>
  #include <stdlib.h>
  
  int main(void)
  {
      int status;
      puts("Hello World!");
      status = fflush(stdout);
      if (status < 0)  { return EXIT_FAILURE; }
      return EXIT_SUCCESS;
  }

  return (printf("Hello world!\n") < 0) && fflush(stdout);

  int x = printf("Hello world!\n");
  if(x<0) return x; // maybe fflush here, too, ignoring errors?
  return fflush(stdout);