Subject: bug#6176: [PATCH 2/2] sort: --debug: output data independent key warnings

From: Pádraig Brady <[email-masked]>
Date: Sat, 15 May 2010 01:26:21 +0100

On 14/05/10 22:47, Pádraig Brady wrote:
> On 14/05/10 22:23, Paul Eggert wrote:

>> Something like the following diagnostic would be far more helpful for
>> users who are not 'sort' experts:
>>
>>   sort: obsolescent key `+2 -4' used; consider `-k 3,4' instead
>>
>> Can you please arrange for that?

I did that using this chunk.
Note that it doesn't reproduce char offsets or flags
on the old or new formats, but they're the same on
both formats, so it's not worth the complexity I think.

if (key->obsolete_used)
  {
    /* obsolescent syntax +A.x -B.y is equivalent to:
         -k A+1.x+1,B.y   (when y = 0)
         -k A+1.x+1,B+1.y (when y > 0)  */
    char obuf[INT_BUFSIZE_BOUND (size_t) * 2 + 4]; /* +# -#  */
    char nbuf[INT_BUFSIZE_BOUND (size_t) * 2 + 5]; /* -k #,#  */

    char *po = obuf;
    char *pn = nbuf;

    size_t sword = key->sword;
    size_t eword = key->eword;
    if (sword == SIZE_MAX)
      sword++;

    po += sprintf (po, "+%" PRIuMAX, (uintmax_t) sword);
    pn += sprintf (pn, "-k %" PRIuMAX, (uintmax_t) sword + 1);
    if (key->eword != SIZE_MAX)
      {
        po += sprintf (po, " -%" PRIuMAX, (uintmax_t) eword + 1);
        pn += sprintf (pn, ",%" PRIuMAX,
                       (uintmax_t) eword + 1 + (key->echar == SIZE_MAX));
      }
    error (0, 0, _("obsolescent key `%s' used; consider `%s' instead"),
           obuf, nbuf);
  }

That latest patch is at http://url.ie/660o

cheers,
Pádraig.