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term::receive(3tcl) Terminal control term::receive(3tcl)


term::receive - General input from terminals


package require Tcl 8.4

package require term::receive ?0.1?

::term::receive::getch ?chan?

::term::receive::listen cmd ?chan?

cmd process string

cmd eof

::term::receive::unlisten ?chan?


This package provides the most primitive commands for receiving characters to a terminal. They are in essence convenient wrappers around the builtin commands read and fileevent.

::term::receive::getch ?chan?
This command reads a single character from the channel with handle chan and returns it as the result of the command.

If not specified chan defaults to stdin.

It is the responsibility of the caller to make sure that the channel can provide single characters. On unix this can be done, for example, by using the command of package term::ansi::ctrl::unix.

::term::receive::listen cmd ?chan?
This command sets up a filevent listener for the channel with handle chan and invokes the command prefix cmd whenever characters have been received, or EOF was reached.

If not specified chan defaults to stdin.

The signature of the command prefix is

This method is invoked when characters were received, and string holds them for processing.
This method is invoked when EOF was reached on the channel we listen on. It will be the last call to be received by the callback.
::term::receive::unlisten ?chan?
This command disables the filevent listener for the channel with handle chan.

If not specified chan defaults to stdin.


This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category term of the Tcllib Trackers []. Please also report any ideas for enhancements you may have for either package and/or documentation.

When proposing code changes, please provide unified diffs, i.e the output of diff -u.

Note further that attachments are strongly preferred over inlined patches. Attachments can be made by going to the Edit form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar.


character input, control, get character, listener, receiver, terminal


Terminal control


Copyright (c) 2006 Andreas Kupries <>
0.1 tcllib