On 2024-11-19 09:53, Pádraig Brady wrote:
Do we really want to treat NUL and NULL strings differently?
$ src/printf '%d\n'
0
$ src/printf '%d\n' ''
printf: ‘’: expected a numeric value
0
Both behaviors are required by POSIX, so yes, we want to treat them
differently. Also, it makes sense to treat '' like ' '; we report an
error for the latter so we should report it for the former too.
More problematically I think is it's also inconsistent with %s
$ src/printf '%s'
$ src/printf '%s' ''
I don't see a problem there. As per POSIX, missing string arguments are
treated as empty strings, whereas missing numeric arguments are treated
as zero.
That's different to bash and dash.
AIX and Solaris 10 printf do things the right way (i.e., conform to
POSIX) - not surprising as AIX at least has gone through POSIX
conformance tests. I expect the GNU divergence from tradition was
accidental, as it doesn't make sense for printf to treat '' differently
from other non-numbers.
I filed bug reports for both Bash and Dash; see:
https://lists.gnu.org/r/bug-bash/2024-11/msg00149.html
https://lore.kernel.org/dash/20241119193211.1585716-1-egg...@cs.ucla.edu/T/#u
BTW after we decide the best operation, we should update NEWS.
Thanks, good point. How about something like the following:
printf now diagnoses attempts to treat empty strings as numbers, as per
POSIX. For example, "printf '%d' ''" now issues a diagnostic and fails
instead of silently succeeding.
