It is sad to see that something is stated "RANDOM" and it is in reality not random and still in OpenBSD. This misleads people.
> Sent: Friday, November 04, 2016 at 7:27 PM > From: Shazaum <shaz...@bsd.com.br> > To: misc@openbsd.org > Subject: Re: Why isn't "sort -R" random? > > Sorry for saying this, but debian it would not be wrong... > > # sort -R a.txt > 7 > 7 > 7 > 7 > ... > > On 11/04/2016 02:17 PM, Joel Wir��mu Pauling wrote: > > Pipe through uniq and you'll get what you are after. > > > > Design intent for sort, as others point out this behaviour is documented. > > > > On 4 November 2016 at 11:47, Christian Gruhl <cgr...@uni-kassel.de> wrote: > > > >> Hi minek, > >> > >> On 11/04/2016 04:41 PM, minek van wrote: > >>> Hello, > >>> > >>> # strings /dev/arandom | grep -o '[[:print:]]' | head -100 > a.txt > >>> # sort -R a.txt > >>> K > >> ... > >>> 9 > >>> # uname -mrs > >>> OpenBSD 6.0 amd64 > >>> # > >>> # sort -R a.txt > b.txt > >>> # cksum b.txt > >>> 3374888359 200 b.txt > >>> # sort -R a.txt > b.txt > >>> # cksum b.txt > >>> 109071951 200 b.txt > >>> # sort -R a.txt > b.txt > >>> # cksum b.txt > >>> 3441576000 200 b.txt > >>> # > >>> > >>> from: http://man.openbsd.org/OpenBSD-current/man1/sort.1 > >>> > >>> -R, --random-sort, --sort=random > >>> > >>> Sort lines in random order. This is a random permutation of the > >> inputs with the exception that equal keys sort together. It is > >> implemented by hashing the input keys and sorting the hash values. The > >> hash function is randomized with data from arc4random_buf(3), or by file > >> content if one is specified via --random-source. If multiple sort fields > >> are specified, the same random hash function is used for all of them. > >>> Although the "b.txt" differs, if we check it by the human eye... that > >> is not random.. **Why**? Why is it called random, WHEN IT IS NOT > >> RANDOM?! Random should mean RANDOM. Not "almost" random.. > >>> The same can be seen on ex.: RHEL7. > >>> > >> I would guess this is the desired behavior. The man page cited by you > >> also states: > >> > >> 'This is a random permutation of the inputs with the exception that > >> equal keys sort together. It is implemented by hashing the input keys > >> and sorting the hash values.' > >> > >> So clearly same values/strings will be put together. > >> > >> Best wishes > >> > >> Chris > >> > >> [demime 1.01d removed an attachment of type application/pkcs7-signature > >> which had a name of smime.p7s]
