On 04/10/2021 21:01, Paul Eggert wrote:
On 10/4/21 08:58, Pádraig Brady wrote:
The --debug option points out the issue:
$ printf '%s\n' 1,a 0,9 | sort --debug -nk1 -t ,
sort: key 1 is numeric and spans multiple fields
1,a
_
___
0,9
___
___
As Juncheng points out, it is a bit odd that -n and -g disagree here,
even in locales where ',' is not a decimal point. For example:
$ printf '1,a\n0,9\n' | sort -gk1 -t, --debug
sort: text ordering performed using ‘en_US.UTF-8’ sorting rules
sort: key 1 is numeric and spans multiple fields
0,9
_
___
1,a
_
___
$ printf '1,a\n0,9\n' | sort -nk1 -t, --debug
sort: text ordering performed using ‘en_US.UTF-8’ sorting rules
sort: key 1 is numeric and spans multiple fields
1,a
_
___
0,9
___
___
The difference here is due to ',' being treated as a thousands sep,
not a decimal point. So Juncheng to specifically answer your question,
0,9 is being interpreted as 9, which sorts after 1,a. For e.g. consider:
$ printf '%s\n' 1,a 0,900 | sort -s -k1,1g --debug
0,900
_
1,a
_
$ printf '%s\n' 1,a 0,900 | sort -s -k1,1n --debug
1,a
_
0,900
_____
Given the various groupings possible (depending on locale
one can group in 2, 3, 4, 5 digits) we effectively just
ignore the grouping separator in numeric mode, hence the difference.
Note in locales where , is a decimal point we do get
consistent order between -g and -n as expected:
$ printf '%s\n' '1,a' '0,9' | LC_ALL=fr_FR.utf8 sort -s -k1,1n --debug
sort: tri du texte réalisé en utilisant les règles de tri « fr_FR.utf8 »
0,9
___
1,a
__
$ printf '%s\n' '1,a' '0,9' | LC_ALL=fr_FR.utf8 sort -s -k1,1g --debug
sort: tri du texte réalisé en utilisant les règles de tri « fr_FR.utf8 »
0,9
___
1,a
__
For completeness we do have another issue with grouping separators,
where we don't support multi-byte separators appropriately.
For e.g. fr_FR.utf8 uses "narrow non breaking space" as the separator,
which we don't support:
$ sep=$(LC_ALL=fr_FR.utf8 locale thousands_sep)
$ printf '%s\n' 0800 "0${sep}900" | LC_ALL=fr_FR.utf8 sort -s -k1,1n --debug
sort: tri du texte réalisé en utilisant les règles de tri « fr_FR.utf8 »
0 900
_
0800
____
cheers,
Pádraig
