Function load_buffer

src/csplit.c:453–494

   (in which case end-of-file must have been encountered). */

static bool
load_buffer (void)
{
  if (have_read_eof)
    return false;

  /* We must make the buffer at least as large as the amount of data
     in the partial line left over from the last call,
     plus room for a sentinel '\n'. */
  idx_t bytes_wanted = MAX (START_SIZE, hold_count + 1);

  while (true)
    {
      struct buffer_record *b = get_new_buffer (bytes_wanted);
      idx_t bytes_alloc = b->bytes_alloc;
      idx_t bytes_avail = bytes_alloc;
      char *p = b->buffer;

      /* First check the 'holding' area for a partial line. */
      if (hold_count)
        {
          p = mempcpy (p, hold_area, hold_count);
          b->bytes_used += hold_count;
          bytes_avail -= hold_count;
          hold_count = 0;
        }

      b->bytes_used += read_input (p, bytes_avail - 1);

      if (record_line_starts (b) != 0)
        {
          save_buffer (b);
          return true;
        }

      free_buffer (b);
      if (have_read_eof)
        return false;
      if (ckd_add (&bytes_wanted, bytes_alloc, bytes_alloc >> 1))
        xalloc_die ();
    }
}

/* Return the line number of the first line that has not yet been retrieved.
   Return 0 if no lines available.  */