SCSI device numbers

[Mike Jeays]

I have at present two emulated SCSI devices on my system; a USB flash
drive, and a DVD-writer.

They get assigned:
 
 0,0,0     0) 'SanDisk ' 'Cruzer Micro    ' '2033' Removable Disk
 2,0,0   200) 'HL-DT-ST' 'DVDRAM GSA-4160B' 'A300' Removable CD-ROM

if the USB device is present at boot time (I think).

So my script for burning CDs, which says:
  mkisofs -J -L -R -o x1.iso "$*"
  cdrecord -v dev=2,0,0 x1.iso
  rm -f x1.iso
is very fragile.

How should I do it?  Write a script to read the output of cdrecord
-scanbus and grab the device number?  There has to be a "right" way, and
instinct says this isn't it.