Readln on ki-shell (windows )

Hi,

in ki-shell I tried
var x:String?=readln()
Using keyboard I type 123456 and enter. Nothing happens. Then I pressed Ctrl+z . I have got my data in x.
In readln doc it is written

LF or CRLF is treated as the line terminator. Line terminator is not included in the returned string.

Why do i need ctrl+z?

x.length is 7 with

x?.get(6) 
Char =