passwd

For some time, I was having trouble getting the arrow keys to function correctly in my terminal sessions when logging into one of my remote Linode servers running Ubuntu 10.04. Whenever I pressed an arrow key, instead of moving the cursor or going up and down the command history, I would get a string of gibberish like [[A^[[B^[[D^[[C. Not very helpful!

So, after some searching, I found that the cause for this is an incorrect shell environment being set in the passwd file. To fix this problem, simply edit the /etc/passwd file and change the final string (after the last :) to /bin/bash (it is set to /bin/sh if you create a user via the command line/useradd):

$ sudo nano /etc/passwd

Change this:
<username>:x:1000:1000::/home/<username>/:/bin/sh

to this:
<username>:x:1000:1000::/home/<username>/:/bin/bash

...and then save the file, log out, and log back in. Problem solved!