Re: [lm-sensors] [Patch] libsensors: Introduce error string -

[Jean Delvare <khali@linux-fr.org>]

On Thu, 29 Jan 2009 12:12:28 +0100, Andre Prendel wrote:
> On Thu, Jan 29, 2009 at 10:57:03AM +0100, Jean Delvare wrote:
> > Hi Andre,
> > 
> > On Thu, 29 Jan 2009 10:09:45 +0100, Andre Prendel wrote:
> > > sensors_error() returns NULL if errnum is not valid. Returning
> > > "Unknown error" in this case, makes output clearer than:
> > > 
> > > foo: (null)
> > > 
> > > and prevents error output/logging from segmentation faults.
> > > 
> > > What do you think?
> > > 
> > > Andre
> > > 
> > > Signed-off-by: Andre Prendel <andre_prendel@gmx.de>
> > > ---
> > > 
> > > --- lm-sensors-dev/lib/error.c	2009-01-26 17:43:43.000000000 +0100
> > > +++ my-lm-sensors/lib/error.c	2009-01-28 22:49:53.000000000 +0100
> > > @@ -33,7 +33,7 @@ void (*sensors_fatal_error) (const char 
> > >  						sensors_default_fatal_error;
> > >  
> > >  static const char *errorlist[] = {
> > > -	/* Invalid error code    */ NULL,
> > > +	/* Invalid error code    */ "Unknown error",
> > >  	/* SENSORS_ERR_WILDCARDS */ "Wildcard found in chip name",
> > >  	/* SENSORS_ERR_NO_ENTRY  */ "No such subfeature known",
> > >  	/* SENSORS_ERR_ACCESS_R  */ "Can't read",
> > 
> > Out of curiosity: did you actually hit this problem in real life?
> 
> No, I didn't. It's just theoretical.
>  
> > I was about to say that the caller was supposed to check for NULL, but
> > apparently neither sensors nor sensord nor even libsensors does, so...
> 
> IMO error reporting should be very stable. If the caller checks
> return value carefully it's fine too. Fprintf() isn't a problem. But I
> don't know what about vsnprintf(), syslog().
> 
> > I guess you're right, having an error string instead of NULL would be
> > better. Actually that's what libsensors 2.x did, I can't remember why I
> > changed that in 3.x:
> > http://www.lm-sensors.org/changeset/4854
> > 
> > Probably I thought it was not supposed to happen, but I guess it may
> > actually happen if mixing a recent application with an older version of
> > libsensors.
> > 
> > So I am pretty much inclined to apply your patch.
> 
> Vous avez le choix. :)

Sicherlich :)

Patch applied, thanks. If you intend to contribute to the lm-sensors
project again on a regular basis, please let me know, we can create an
account for you.

-- 
Jean Delvare

_______________________________________________
lm-sensors mailing list
lm-sensors@lm-sensors.org
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors