From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: [PATCH iproute2 net-next 0/3] ss: Allow selection of columns to be displayed Date: Tue, 30 Oct 2018 10:34:45 -0600 Message-ID: <7ffc00c8-bdf6-5c75-564e-2663494bda5d@gmail.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: "Yoann P." , Stephen Hemminger , netdev@vger.kernel.org To: Stefano Brivio Return-path: Received: from mail-pf1-f195.google.com ([209.85.210.195]:36641 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727411AbeJaB3A (ORCPT ); Tue, 30 Oct 2018 21:29:00 -0400 Received: by mail-pf1-f195.google.com with SMTP id j22-v6so2303305pfh.3 for ; Tue, 30 Oct 2018 09:34:48 -0700 (PDT) In-Reply-To: Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 10/30/18 9:05 AM, Stefano Brivio wrote: > Now that we have an abstraction for columns, it's relatively easy to > selectively display only some of them, and Yoann has a use case for it. > > Patch 1/3 fixes a rendering issue that shows up only when display of > arbitrary columns is disabled. Patch 2/3 implements the relevant option, > and patch 3/3 makes the output more readable when some columns are > disabled. > > I like the intent, and I have prototyped something similar for 'ip'. A more flexible approach is to use format strings to allow users to customize the output order and whitespace as well. So for ss and your column list (winging it here): netid = %N state = %S recv Q = %Qr send Q = %Qs local address = %Al lport port = %Pl remote address = %Ar remote port = %Pr process data = %p ... then a format string could be: "%S %Qr %Qs %Al:%Pl %Ar:%Pr %p\n" or for csv output: "%S,%Qr,%Qs,%Al,%Pl,%Ar,%Pr,%p\n" I have not had time to look into an implementation for ip. Conceptually - and scanning the kernel's vsprintf code - it does not look that difficult, just time consuming on the frontend with the initial setup.