exclon 1 user commands djbwares exclon reserve tty for exclusive use exclon exclon attempts to reserve your terminal for exclusive use. This means that any attempt to open your terminal, including through /dev/tty, will fail. excloff attempts to undo the effect of exclon1. Exception: root can still open your terminal. On most systems this means that talk1 is not affected by exclon even though write1 is. excloff1 the reverse of this command exclon was originally part of Daniel J. Bernstein's ptyget toolset in 1996. Original code and documentation by Daniel J. Bernstein. Documentation modernizations by Jonathan de Boyne Pollard.