Q:

opposite of eject command?

I have a ton of CDs to image, and I just got curious. I can eject with the eject command. What command inserts the disk tray back into the CD drive?
yes it is the type that can pull the tray back in. I searched the eject man page, and guessed at the command, but i couldn't figure it out. 

A:

To close CD tray with Ubuntu 11.04 or 14.04:
eject -t

or toggle with
eject -T

for a summary
eject --help

