computer.pullSignal works like event.pull does...
And you should most certainly read up on these functions before just using them.
if you do computer.pullSignal, it'll block until a signal is recieved, this could be component_added, component_removed, key_down or key_up alot of information is being sent ...
So you take down each keypress, and build it into a string
A very very crude example would be
local str = ''
local c = true
while c == true do
local e,_, uni, code = computer.pullSignal ()
if e == 'key_down' then -- So a key was pressed, yay, this is what we want
if uni