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#66253
sort manpage should be more explicit
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Your bug report
#66253: sort manpage should be more explicit
which was filed against the coreutils package, has been closed.
The explanation is attached below, along with your original report.
If you require more details, please reply to 66253 <at> debbugs.gnu.org.
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66253: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=66253
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On 28/09/2023 11:11, Jorge Stolfi wrote:
> The full documentation of sort explains that numeric sorting (as in
> "sort -n") accepts a leading "-" sign, decimal points, thousands
> separators, etc, but does not accept an explicit "+" sign. Values with
> explicit "+" are treated as numeric 0 and ties are broken by alpha sort.
>
> However, the manpage only says that "-n" "compares according to string
> numerical value" -- and one would expect the numerical value of "+100"
> to be 100, not zero.
>
> It took me an hour to figure out that my "sort -n" was failing because
> of this "feature". Surely many users have wasted time too, or worse.
> So please either
>
> 1) explain precisely IN THE MANPAGE what is a valid number;
>
> 2) make numeric sort accept a leading "+", as users would expect;
>
> 3) make numeric sort abort with an error message if any field that is
> supposed to be sorted numerically is not a valid number.
>
> I think the best solution for users would be to implement all three of
> these...
>
> Thank you, and all the best
Note the --debug option really helps with all this:
$ printf '%s\n' '+4' ' 5' '-1,2.3' | sort -s -n --debug
sort: note numbers use ‘.’ as a decimal point in this locale
-1,2.3
______
+4
^ no match for key
5
_
In saying that, sorting numbers is such a common use case,
it's probably worth adding an extra couple of lines to the man page.
I think I'll apply the following later:
-n, --numeric-sort compare according to string numerical value.
leading blanks, negative sign, decimal point,
and thousands separators are supported.
cheers,
Pádraig
[Message part 3 (message/rfc822, inline)]
The full documentation of sort explains that numeric sorting (as in
"sort -n") accepts a leading "-" sign, decimal points, thousands
separators, etc, but does not accept an explicit "+" sign. Values with
explicit "+" are treated as numeric 0 and ties are broken by alpha sort.
However, the manpage only says that "-n" "compares according to string
numerical value" -- and one would expect the numerical value of "+100"
to be 100, not zero.
It took me an hour to figure out that my "sort -n" was failing because
of this "feature". Surely many users have wasted time too, or worse.
So please either
1) explain precisely IN THE MANPAGE what is a valid number;
2) make numeric sort accept a leading "+", as users would expect;
3) make numeric sort abort with an error message if any field that is
supposed to be sorted numerically is not a valid number.
I think the best solution for users would be to implement all three of
these...
Thank you, and all the best
--jorge
--
Jorge Stolfi - Professor Titular/Full Professor
Instituto de Computação/Computer Science Dept
Universidade Estadual de Campinas/State University of Campinas
Campinas, SP - Brazil
This bug report was last modified 1 year and 235 days ago.
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