Function next_file_name

src/split.c:405–511

   string 'outfile'.  */

static void
next_file_name (void)
{
  /* Index in suffix_alphabet of each character in the suffix.  */
  static idx_t *sufindex;
  static idx_t outbase_length;
  static idx_t outfile_length;
  static idx_t addsuf_length;

  if (! outfile)
    {
      bool overflow, widen;

new_name:
      widen = !! outfile_length;

      if (! widen)
        {
          /* Allocate and initialize the first file name.  */

          outbase_length = strlen (outbase);
          addsuf_length = additional_suffix ? strlen (additional_suffix) : 0;
          overflow = ckd_add (&outfile_length, outbase_length + addsuf_length,
                              suffix_length);
        }
      else
        {
          /* Reallocate and initialize a new wider file name.
             We do this by subsuming the unchanging part of
             the generated suffix into the prefix (base), and
             reinitializing the now one longer suffix.  */

          overflow = ckd_add (&outfile_length, outfile_length, 2);
          suffix_length++;
        }

      idx_t outfile_size;
      overflow |= ckd_add (&outfile_size, outfile_length, 1);
      if (overflow)
        xalloc_die ();
      outfile = xirealloc (outfile, outfile_size);

      if (! widen)
        memcpy (outfile, outbase, outbase_length);
      else
        {
          /* Append the last alphabet character to the file name prefix.  */
          outfile[outbase_length] = suffix_alphabet[sufindex[0]];
          outbase_length++;
        }

      outfile_mid = outfile + outbase_length;
      memset (outfile_mid, suffix_alphabet[0], suffix_length);
      if (additional_suffix)
        memcpy (outfile_mid + suffix_length, additional_suffix, addsuf_length);
      outfile[outfile_length] = 0;

      free (sufindex);