Re: Problem parsing %s in udev rules

[Andrew Patterson <andrew.patterson@hp.com>]

[-- Attachment #1: Type: text/plain, Size: 2293 bytes --]

On Wed, 2004-10-13 at 16:56 -0700, Greg KH wrote:
> On Wed, Oct 13, 2004 at 05:13:12PM -0600, Andrew Patterson wrote:
> > > We already trim it off when matching, but we also allow matching if you
> > > do put the spaces in there.  This patch breaks that, right?
> > 
> > Correct, I have a new patch that trims after the comparison, so it
> > should work in both cases. 
> 
> Thanks, I've applied this.

Thanks.

> 
> > > > I also wonder if it might be a good idea to do some sort of
> > > > transformation for characters in an attribute that are illegal in a file
> > > > system, rather than just chopping everything off. e.g, spaces that are
> > > > not leading or trailing would be changed to underscores.
> > > 
> > > ick, no.
> > 
> > Really?  Care to elaborate? 
> > 
> > Do you not like any transformation (besides the "let's chop off
> > everything after anything illegal") or just the underscores for spaces
> > one?  Perhaps a configuration value to make it optional? This sort of
> > thing might relieve a lot of the script writing that must be done to
> > handle cases that may be common.
> 
> Have you run into any cases where something like this is needed?  I
> don't really want to do any transformation within udev itself if
> possible, as it's a slippery slope down...  Helper programs can be used
> if people run into anything really nasty, and the fact that this hasn't
> come up yet, lends me to belive it really isn't a problem.  
> 
> Do you have any device that would need such transformation?

Need, no.  Want perhaps.  Example: using the following rule:

BUS="scsi", KERNEL="sd*", NAME="%k", SYMLINK="scsi_disks/%s{vendor}-%
s{model}"

I have this stupid disk drive that has the following vendor and model
entry:

Vendor: HP 36.4G Model: ST336753LC

So the resulting device file created by udev is
/dev/scsi_disks/HP-ST336753LC

Intuitively, I would expect /dev/scsi_disks/HP 36.4G-ST336753LC.
Given that spaces are bad, it would be be nice to see something like:

/dev/scsi_disks/HP_36.4G-ST336753LC.

Is the %s stuff used a lot?  I am somewhat surprised that I am the only
one running into issues like this.

Andrew

> 
> thanks,
> 
> greg k-h
> 
-- 
Andrew Patterson                
Hewlett-Packard

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 189 bytes --]