source: udev/check-cdrom.sh@ dd6636b

#!/bin/bash

pos=0
n=0
sp="$1"
what="$2"
found=0

[ -e /proc/sys/dev/cdrom/info ] || exit 1

/bin/cat /proc/sys/dev/cdrom/info | { 
        while read line; do
                if [ "$found" = "0" -a "${line/drive name:}" != "$line" ]; then
                        set ${line/drive name:} 
                        while [ $# -gt 0 ]; do
                                pos=$[$pos+1]
                                if [ "$1" == "$sp" ]; then
                                        found=1
                                        break
                                fi
                                shift
                        done
                        [ "$found" = "0" ] && exit 1
                elif [ "${line/$what:}" != "$line" ]; then
                        set ${line##*$what:}    
                        while [ $# -gt 0 ]; do
                                n=$[$n+1]
                                if [ "$n" == "$pos" ]; then
                                        if [ "$1" = "1" ]; then
                                                exit 0
                                        fi
                                        break
                                fi
                                shift
                        done
                fi    
        done
exit 1
}