Cannot use 'tell application "System Events" to keystroke

Have you verified that you have assistant devices turned on?

Could put all commands in an applescript and then invoke from the command line.

could use unix sleep 1 instead of ... < just thought that I'd comment. >

osascript -e 'tell application "System Events" to delay 1.0'; \

Mavericks doesn't seen to give focus to the username field when booting up. A more sophisticated script could address this, but it would run afoul of the tighter security around access for assistive devices. The simpler solution is to run the command "killall loginwindow" before running osascript. When the loginwindow comes back, focus is on the username field so the osascript commands will work. You typically don't need the delay lines on modern hardware. If using ARD or a similar tool killall loginwindow must be run separately, since nothing coming immediately after it will be processed.

run as root

osascript <<EndOfMyScript

tell application "System Events"

keystroke "your user"

delay 5.0

keystroke return

delay 1.0

keystroke "your password"

keystroke return

delay 1.0

keystroke return

end tell

EndOfMyScript