Administering the ttymon port monitor

Administering the ttymon port monitor

ttymon is a port monitor invoked by the Service Access Controller (SAC) to monitor asynchronous terminal devices, such as terminals and modems. From UNIX System V Release 4 onward, ttymon performed the functions that getty and uugetty performed in previous releases. Like getty and uugetty, ttymon sets terminal modes and line speeds for the port to which the user is connected, allowing communication with the service associated with that port.

ttymon differs from getty and uugetty in several important ways:

ttymon provides any configured service (such as the shell or a database). getty and uugetty provided only login service.
Each invocation of ttymon can support multiple ports. getty and uugetty supported only one port per invocation.
ttymon is a persistent process that continues to run after the service process is initiated. The getty and uugetty processes were replaced by the process of the service invoked.
ttymon can take advantage of all STREAMS I/O capabilities.
Line disciplines are configurable on a per-port basis.
ttymon provides an optional autobaud facility that automatically determines the line speed of the hardware connected to any port monitored by a ttymon port monitor.