Is there any option to use Amazon Cloud Drive from terminal (Linux)?
As you probably know, Amazon did not release any Cloud Drive client for Linux. Is there any other option to access ACD from terminal?
At the time of asking the answer was unfortunately No, but no more! You can now easily access Amazon Cloud Drive from the terminal using an OpenSource client called acd_cli, which is written in Python (3) and runs under Windows / Linux / Mac. There was a list of authorised apps here: https://www.amazon.com/clouddrive/apps but it now only shows official Amazon clients for MacOS and Windows.
These are mostly "cloud-to-cloud-sync" services and absolutely not what you are looking for, though. Even the Amazon build app for Mac OS X, which actually is a stand-alone uploader, does not provide a command-line-interface and you can not upload files from the console.
The only hope is an open REST-based API that allows interaction with Amazon Cloud Drive, which is good news, as it essentially means, anybody could build a client for it.
One app called ExpanDrive also supports Amazon Cloud Drive by now due to user requests. That doesn't help much, though, since they also don't have a Linux version of their (commercial) app, yet, but they are also working on that apparently (originally to be released mid-summer 2015). There are a number of similar products such as Netdrive (only supports Windows). The (discontinued) DragonDisk already has linux command-line binaries and supports:
Amazon S3®, Google Cloud Storage®, and all cloud storage services that provides compatibility with Amazon S3 API
You could of course try to run either of those through wine.
There is also some software that lifehacker mentions to be used under Windows. I imagine you could use wine to run it (or any of the former tools) to see if you can make those work.
If all this doesn't make you happy right now:
There is another idea I thought about: Terminal-based web browsing. Install w3m or any alternative (lynx, links2, etc.) and try it out - I didn't get very far, but I haven't tested all of them and you can at least log into the website from your terminal-based browser. I also couldn't test the image-rendering capabilities (you need xterm for that). Here is a decent guide.
sudo apt-get install w3m w3m-img
w3m cloud.amazon.com
The problem is that it doesn't display any files and you will have trouble with the drag & drop upload functionality. So we are generally out of luck.
I've been using http://rclone.org/ with much success. I find it quite mature and robust. It also includes bandwidth throttling that works!
Edit: Please note that this is no longer the case. Amazon Drive has banned rclone and this appears to be permanent.
Apparently there's another newbie command line access project as well.
The ACD 3rd Party Tools page lists acd_cli, a command line access tool in the alpha stages.