Hi nab,
On Sun, Dec 15, 2024 at 09:17:59PM +0100, Ahelenia Ziemiańska wrote:
> Compare, given:
> #include <stdlib.h>
> #include <stdio.h>
> #include <string.h>
> int compar(const char **l, const char **r) {
> return strverscmp(*l, *r);
> }
> int main(int argc, char ** argv) {
> qsort(argv + 1, argc - 1, sizeof(*argv), compar);
> for(int i = 1; i < argc; ++i)
> puts(argv[i]);
> }
> yields:
> $ /bin/ls -v1 a* # coreutils ls
> a-1.0a
> a-1.0.1a
> $ ../vers a* # as above
> a-1.0.1a
> a-1.0a
> $ ls -v1 a* # voreutils ls @ 5781698 with strverscmp()-equivalent sorting
> a-1.0.1a
> a-1.0a
Should we file a bug against glibc strverscmp(3)? We probably should.
> compare also the results for real data like
> netstat-nat-1.{0,1{,.1},2,3.1,4{,.{1,2,3,4,5,6,7,8,9,10}}}.tar.gz
>
> Thus, coreutils ls -v does NOT use strverscmp(3),
> it uses a similar algorithm that actually properly sorts versions,
> not just single numbers.
First time I learn about ls(1) having a -v option. :|
Was people too lazy to type `ls | sort -V`?
>
> Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@xxxxxxxxxxxxxxxxxx>
> ---
> man/man3/strverscmp.3 | 15 +++++----------
> 1 file changed, 5 insertions(+), 10 deletions(-)
>
> diff --git a/man/man3/strverscmp.3 b/man/man3/strverscmp.3
> index 41bc1ddbd..7c3643860 100644
> --- a/man/man3/strverscmp.3
> +++ b/man/man3/strverscmp.3
> @@ -25,16 +25,7 @@ .SH DESCRIPTION
> orders them
> .IR jan1 ", " jan10 ", ..., " jan2 ", ..., " jan9 .
> .\" classical solution: "rename jan jan0 jan?"
> -In order to rectify this, GNU introduced the
> -.I \-v
> -option to
> -.BR ls (1),
> -which is implemented using
> -.BR versionsort (3),
> -which again uses
> -.BR strverscmp ().
> -.P
> -Thus, the task of
> +The task of
> .BR strverscmp ()
> is to compare two strings and find the "right" order, while
> .BR strcmp (3)
> @@ -44,6 +35,10 @@ .SH DESCRIPTION
> .BR LC_COLLATE ,
> so is meant mostly for situations
> where the strings are expected to be in ASCII.
> +This is not actually the ordering produced by
> +.BR ls (1)
> +.BR -v .
> +.\" because it considers a-1.0.1a < a-1.0a; this is not what you want
I hate this reference to ls(1). ls(1) should not even have a -v option.
Please refer to sort(1) instead. I would wipe any references to file
names in this page, as I don't think they are relevant at all.
And the reference to sort(1), I'd put it in BUGS, saying that this API
is broken, and does not sort properly. Sounds good?
Have a lovely night!
Alex
> .P
> What this function does is the following.
> If both strings are equal, return 0.
> --
> 2.39.5
--
<https://www.alejandro-colomar.es/>
Attachment:
signature.asc
Description: PGP signature
