Subject: Re: bug#20745: I would like to make a request for the sort command

From: Eric Blake <[email-masked]>
Date: Mon, 08 Jun 2015 08:14:20 -0600

On 06/08/2015 05:14 AM, Stephane Chazelas wrote:

> Maybe there's a way to allow that without having to implement
> the specifics in sort.
> 
> Like sort key flags to invoke commands:
> 
>    sort '-k1,1|ip2hex' '-k2,2n|roman2int' '-k3,3|iconv -t us//TRANSLIT'

That would result in a LOT of process overhead (one command spawned per
sort key per line).  True, it would be more generic, but the performance
would suffer compared to having a direct way to do the sorting within
the current process.  It's going to be more efficient to do a single
pre-process pass, then sort, then post-process, with a complicated
script language doing the right processing per field in a single pass,
than to do one conversion per key per row.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org