elixir, 218 bytes

Result

AC

Duration

1890ms

Code [DL]

defmodule F do
def f(s,t)do
case IO.gets("")do
:eof->IO.write String.slice(String.trim_trailing(t)<>String.duplicate("*",99),0,String.length String.trim_trailing s)
t->IO.write s
f(s,t)
end
end
end
F.f(IO.gets(""),"")

stdin

                                                T 
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                   K                              

stdout

                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                                                T 
                   K*****************************

stderr

strace