Ethan Mallove <emallove at yahoo dot com> wrote: > > why is ctrl-d a logout command >instead of NULL? > Because that's what ctrl-d is supposed to be for!
In the ASCII character code set, ctrl-d is defined as the EOT signal, short for "End Of Transmission". So Unix (and consequently Cygwin) were just following the published standard. NUL would, in general, be a terrible choice for an OS to adopt because NUL characters have perfectly useful applications in serial data streams (e.g., as something that you can insert into a stream to affect the timing without altering the message). ctrl-z, by the way, used as the terminator by MSDOS and other early PC operating systems was an unintentionally humorous choice. It's defined as the SUB character, used as a placeholder to indicate the data lost during a garbled transmission. Steve Z -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Bug reporting: http://cygwin.com/bugs.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
