Short for ''pseudo teletype'', but more commonly referred to as a pseudo terminal.

A pseudo terminal is a pair of character devices, a master device, and a slave device. These allow communication between an application process and a server process. When sending data to pty devices (such as windows), a pty device must exist for every window that is open at any given time.

Also see [expect], a [Tcl] [extension] which deals nicely with ptys
on [UNIX].  Alas, on [Windows] things are a bit problematic.  And
on other Operating Systems, things can be even worse...



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[Helmut Giese] provides in [comp.lang.tcl%|%clt] Tcl source for pty management
[http://groups-beta.google.com/group/comp.lang.tcl/browse_thread/thread/2a434eab8ba68117/];
[Don Libes]
points out that this is less portable than one might hope.