How to eject a Kindle Touch 3rd Generation when it is USB drive mode in Linux command

When I connect my Kindle to a pc for charging, it shows the following link image

https://images-na.ssl-images-amazon.com/images/G/01/00/00/06/73/72/25/673722510.gif

Then, it rejects "charging". doesn't allow me to read a document, so...

1. find the right dev name, for me, it was /dev/sdc1. I am using tail -f /var/log/message with SU
2. eject /dev/sdc
   

One might ask, why do you need this command?. I am a user of FVWM, so I don't have any fancy "click".