Re: Feature Request for 'sort' utility

[Pádraig Brady]

On 27/06/11 13:53, Eric Blake wrote:
> On 06/26/2011 06:05 PM, Bob Proulx wrote:
>> scott n-h wrote:
>>> -I or --ip-address
>>> I'm hoping the usefulness of this would be apparent.
>>
>> The coreutils manual:
>>
>>   
>> http://www.gnu.org/software/coreutils/manual/html_node/sort-invocation.html#sort-invocation
>>
>> Shows an example of sorting IPv4 addresses this way:
>>
>>   sort -s -t. -k 1,1n -k 2,2n -k 3,3n -k 4,4n
> 
> However, there's no easy way to sort IPv6 addresses using existing sort
> keys, so maybe there is indeed room for improvement, if someone would
> care to contribute code.
> 

Well the argument here is whether IP addresses are
a fundamental enough type to support directly within sort,
or whether using the Decorate Sort Undecorate pattern is more appropriate.

Here is an example of using DSU with funcpy¹
which handles the various formats IPV6 addresses can be in:

printf '%s\n' ::03 ::2 ::1 |
funcpy --import socket,struct "
':'.join('%04x' % x for x in
  struct.unpack('>HHHHHHHH',
    socket.inet_pton(socket.AF_INET6,
      x.split()[0])))+'\t'+x
" | sort | cut -f2-

While being more general, this is fairly awkward.
Also there is a binary to ascii step that would
not be required if done internally.
I guess if we were supporting this we'd use the 'I' option.
I'm 50:50 on adding this though, as I'm not
sure how common it is to need to sort IP addresses?

cheers,
Pádraig.

¹ http://www.pixelbeat.org/scripts/funcpy