eject 2.1.5+deb1+cvs20081104-9 (amd64 binary) in ubuntu precise

 This little program will eject CD-ROMs (assuming your drive supports
 the CDROMEJECT ioctl). It also allows setting the autoeject feature.
 .
 On supported ATAPI/IDE multi-disc CD-ROM changers, it allows changing
 the active disc.
 .
 You can also use eject to properly disconnect external mass-storage
 devices like digital cameras or portable music players.