Dropbox has a useful but rather simplistic command-line interface, which I use almost exclusively. The reason I call it simplistic is that when you start Dropbox with dropbox start, all you see is

$ dropbox start
Starting...Done!

It starts Dropbox then brings you right back to the command-line prompt, at which point you have no idea what Dropbox is doing in the background. For me it’s important to know when Dropbox is finished syncing because I prefer to leave Dropbox off otherwise; that is, once the sync is done, I want to know that and then stop Dropbox.

There is a command dropbox status, but all that does is check the status (whether Dropbox is idle, uploading, downloading, indexing, etc.) at the particular moment you call dropbox status, and that’s it. I could of course keep calling dropbox status until it starts to return Idle every time

$ dropbox status
Connecting...
$ dropbox status
Initializing...
$ dropbox status
Starting...
$ dropbox status
Downloading file list...
$ dropbox status
Updating (4 files)
Indexing (4 files)
$ dropbox status
Idle
$ dropbox status
Idle

but there is an easier way to do this: the Linux command watch, which “execute[s] a program periodically, showing output fullscreen.” Suppose I want to check Dropbox’s status every one second. Then I just run

watch -n1 dropbox status

(The option -n1 is short for --interval 1 and always refers to seconds.)

To stop watching the program (to exit watch), just hit Ctrl-C.

When I run Dropbox, I basically just want to start it, watch what it does until it returns Idle every time, and then stop Dropbox. Here is simple alias (to put in .bashrc or .zshrc or whatever) that lets me do that:

alias db='dropbox start && watch -n1 dropbox status && dropbox stop'

With this alias, I just type db at the command line, watch what Dropbox does until I keep seeing Idle, hit Ctrl-C, and then Dropbox stops automatically.