On 14/10/10 11:06, Jim Meyering wrote:
> I noticed that using a field number of SIZE_MAX or larger makes --debug
> give an invalid diagnostic:
>
> $ :|_POSIX2_VERSION=199209 src/sort --debug +$(echo 2^64-1|bc).4 -1.2
> src/sort: using simple byte comparison
> src/sort: obsolescent key `+0 -2' used; consider `-k 1,2' instead
> src/sort: leading blanks are significant in key 1; consider also specifying
> `b'
I'd nearly call that corner case a feature,
as it informs you the passed count has been wrapped.
I.E. the obsolete syntax has a 1-less narrower range
and this is informing you of that fact.
printf "1 2\n" | src/sort -sb --debug +$((2**32-1)) -1
src/sort: using `en_IE.UTF-8' sorting rules
src/sort: obsolescent key `+0 -1' used; consider `-k 1,1' instead
1 2
_
It does mean though, that overflows on the start field
for obsolete syntax do sort the data, while overflows
with the -k syntax do not. We could detect that for
the old syntax, and map overflows to SIZE_MAX-1?
I suppose we could also add a debug warning for when
we do overflow, something along the lines of:
$ src/sort -sb --debug -k$((2**32)) /dev/null
src/sort: 4294967296 is too large, using 4294967295
@@ -3882,6 +3882,8 @@ parse_field_count (char const *string, size_t *val, char
const *msgid)
case LONGINT_OVERFLOW:
case LONGINT_OVERFLOW | LONGINT_INVALID_SUFFIX_CHAR:
*val = SIZE_MAX;
+ if (debug) /* Note --debug must come before keys to diagnose this. */
+ error (0, 0, _("%" PRIuMAX " is too large, using %zu"), n, *val);
break;
cheers,
Pádraig.
