Subject: Re: [iproute PATCH] ip-route: Pretty-print expired routes

From: Stephen Hemminger <[email-masked]>
Date: Fri, 12 Aug 2016 12:58:15 -0700

On Thu, 11 Aug 2016 15:54:50 +0200
Phil Sutter <[email-masked]> wrote:

> On Thu, Aug 11, 2016 at 02:46:26PM +0100, Edward Cree wrote:
> > On 10/08/16 12:14, Phil Sutter wrote:  
> > > Instead of printing 'expires -23sec' for expired (but not yet garbage
> > > collected) routes, print 'expired 23sec' instead.
> > >
> > > Signed-off-by: Phil Sutter <[email-masked]>
> > > ---
> > >  ip/iproute.c | 12 ++++++++++--
> > >  1 file changed, 10 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/ip/iproute.c b/ip/iproute.c
> > > index c52294d298210..a89a26d68be0f 100644
> > > --- a/ip/iproute.c
> > > +++ b/ip/iproute.c
> > > @@ -305,6 +305,14 @@ static void print_rtax_features(FILE *fp, unsigned int features)
> > >               fprintf(fp, " 0x%x", of);
> > >  }
> > >
> > > +static void print_expires(FILE *fp, __s32 expires, int hz)
> > > +{
> > > +     if (expires > 0)
> > > +             fprintf(fp, " expires %dsec", expires/hz);
> > > +     else
> > > +             fprintf(fp, " expired %dsec", -expires/hz);
> > > +}  
> > Perhaps something that differs by more than a single character, to
> > make it stand out more?  I don't know what to suggest, though.  
> 
> Yes, I thought about that, too. At first, I had "expired for %dsec" for
> the second case, but decided that it was a bit too verbose given that
> all route info goes into a single line and is still meant to be
> human-readable. :)
> 
> Cheers, Phil

This makes sense to humans but changing the output format can break some brittle
scripts that parse output of iproute tools.  The risk of incompatibility is a
bigger issue than the small gain in readability. Sorry, not taking this.