Marco d'Itri wrote:
> I am attaching the rules and the script which I am using in the Debian 
> package to generate on demand aliases for CD readers.

This is a bit buggy :(

> choose_rules_file() {
>   [ -e "$RULES_FILE" ] || PRINT_HEADER=1
>   if writeable ${RULES_FILE%/*}; then
>     RO_RULES_FILE='/dev/null'
>   else
>     RO_RULES_FILE=$RULES_FILE
>     RULES_FILE="/dev/.udev/tmp-rules--${RULES_FILE##*/}"
>   fi
> }

Sorry, I don't understand how /dev/.udev/tmp-rules--* is moved to 
/etc/udev/rules.d. In my version, I removed this hack and instead added the rule 
to fail the entire uevent if / is not writeable. Then the udev_retry script that 
runs after mounting filesystems picks the uevents up from /dev/.udev/failed 
(yes, I know that this script is not available in Debian).

> find_next_available() {
>   local links="$(find_all_symlinks $1)"

This contains embedded newlines.

>   local basename=${links%%[0-9]*}

This doesn't work as expected because of newlines. To see the effect, connect 4 
IDE CD-ROMs to one box (special thanks to Archaic from the Linux From Scratch 
team for testing this).

Anyway, the fixed script (adapted to non-Debian systems) and rules are attached.

-- 
Alexander E. Patrakov