Re: [Smartmontools-support]Thanks - and some random ideas

[Bruce A. <ba...@gr...>]

Hi Tim,

> > > I wasn't sure about the usefulness of '%s', but I've just realised that it
> > > is necessary if we are to allow Directives to be used with DEVICESCAN as Tim
> > > suggested (I think that's a good idea, btw.).  
> > 
> > Actually I agree that %s is needed, but don't agree with the reason why.
> > It's only needed to indicate where in the command line argument for the
> > program to be execed the device name should appear.  Eg:
> > /usr/sbin/smartctlreplacement %s -a takes -b arguments -c afterwards
> > /usr/sbin/dougsscsiutility -a takes -b device -c name -d %s -e midway
> > 
> > But the %s is NOT needed for DEVICESCAN, since internally we always know
> > what device we are concerned with.
> 
> But how does the user specify where they want the device name to be
> inserted into the exec string, without the %s?

I completely agree with this justification for having %s.

> I agree that in the case of specific device lines in smartd.conf, the
> user could hard code the same device name into the exec string (bit
> yukky IMO), but in the case of DEVICESCAN neither the user nor the
> called script knows which device tripped the email unless it can be
> passed as a parameter...

I'm still confused by this latter remark.  Since I agree that we need %s
for the reason given previously, this is beating a dead horse.  So here
goes.

Supppose that we didn't have the previous reason for including
%s.  Suppose that we always have (for instance) the convention that the
device name was inserted at the end of the exec string.  Then there would
be no need for %s.  Since, within the smartd code, each time that we
detect a problem with a device, we ALREADY have the device name internally
in cfg->name.  So smartd would just do:
  sprintf(cmdline,"%s %s", users_argument_to_-M_exec, cfg->name);
  system(cmdline);
Thus, the ONLY reason for having %s is the one given above -- that we need
a way to indicate where in the command to be execed the device name should
go.

Cheers,
	Bruce