As we know,when we are operating in ubuntu command console terminal,we type first few letters of command-name or file-name and press tab key instead of type the whole word.We also press up/down arrow key to find out history command we just typed.But if you create a new user with adduser command and want to do some command things with this user,these tab and up/down functional keys won’t work.
Following shows how to enable these functional key:

First,type this command:

cat /etc/passwd

In the output,we can find out that this new user use /bin/sh rather than /bin/bash as its shell.And following command tells me /bin/sh point to dash:

ls -l /bin/sh

So,just edit /etc/passwd and change /bin/sh to /bin/bash in that line.In theory,make /bin/sh point to bash will also do this work.