On Wed, Nov 02, 2005 at 01:05:31AM +0100, Kay Sievers wrote:
> On Tue, Nov 01, 2005 at 02:53:57PM -0800, Patrick Mansfield wrote:
> > If we could set and compare environment variables
>
> Sure we can do that with ENV. '=' sets, '==' compares.
>
> > or compare SYMLINK,
>
> How would we compare the list of sysmlinks?
> True, if on of them matches?
Yes, perhaps:
SYMLINK == "* disk/by-id/scsi-360a98000686f68656c6e7a416f4b6849 *" SYMLINK+="user/name"
I like the above better than using other env variables, it is easier to
read.
> > separate rules file (doesn't have to be separate, just seems like a good
> > idea) could be used to add symlinks to user specified names.
>
> All the persistent symlinks are composed from variables still available
> to match anytime later to add more links.
>
> > i.e. move udev_rules.c:apply_format() into udev_utils.c, and call it
> > before comparison as well as before (AFAIUI) generating names, though I
> > somehow doubt the change is that simple.
> >
> > Then, we could have rules like:
> >
> > KERNEL=="sd*[!0-9]|sr*|dasd*[!0-9]", ENV{ID_SERIAL}=="?*", ENV{ID_FULL_PATH}="disk/by-id/$env{ID_BUS}-$env{ID_SERIAL}"
> > ENV{ID_FULL_PATH}=="?*", SYMLINK+="$env{ID_FULL_PATH}"
>
> Hmm, why this indirection? Can't you just use ID_SERIAL and ID_BUS in
> the second rule again?
Yes, but it is simpler to use one variable, for this and in the by-id
partitions, rather than use "disk/by-id/$env{ID_BUS}-$env{ID_SERIAL}" in
multiple places (it is used in two places today, my scheme would mean two
more references).
But it still would not match, per the issue below, right?
> > Running with udev 069 on FC rawhide, with these rules:
> >
> > SYMLINK=="*foo*" SYMLINK+="user/bar"
>
> SYMLINK lists can't be matched until now.
You mean it is possible with current udev?
> > KERNEL="sdm" ENV{VAL1}="somevalue"
> > KERNEL="sdm" ENV{VAL2}="$env{VAL1}"
>
> The value does not get expanded at the time you assign it, so the later compare
> will look like:
> 'somevalue' == '$env{VAL1}'
>
> which does not match.
Right ... so should udev be changed to avoid that problem?
-- Patrick Mansfield
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