Operating systems provide a range of devices that are real terminals, or things pretending to be real terminals, attached via serial ports (and possibly modems). This package contains tools for running and managing TUI login services on real terminals. It also contains pre-written service bundles for such TUI login services.
Login on real terminals is done with ttylogin services, configured to use those devices.
They are always alias names for other services, that are in turn named after the serial-line "getty" programs that they employ (such as getty, mgetty, and agetty).
Such a TUI login service is a very simple service, which can be managed just like other ordinary services, started and stopped and enabled and disabled in the usual way.
There is one augmentation to ordinary service management: the preset command uses the ordinary preset file mechanism, but can also read the /etc/ttys file.
run scripts look like
Note:
Login services for real terminals have to do a lot more, from auto-sensing line speed to handling special login diversions for faxmodems, BBSes, PPP, and suchlike, than the login services of virtual terminals.
On the one hand, TUI login services for real terminals should not be relying upon any sort of getty program any more.
The use of getty in terminal login has in fact been obsolete since 1988, when one of the earliest service management systems for Unix superseded it with its own mechanisms.
On the other hand, the nosh toolset does not provide chain-loading utilities for these extra mechanisms, and current TUI login services for real terminals hence do still employ various getty programs.
On the gripping hand, the use of faxmodems, BBS "doors", variable speed serial lines to local terminals or to modems, PPP, chat scripts, and suchlike is uncommon in the 21st century.
Theoretically, in the future a lot of this could simplify to assuming a hardwired fixed high BPS rate, default line discipline settings, and no special login diversions; and thus even these residual getty uses could finally be removed.
The services are ttylogin@ttyu0 through to ttylogin@ttyuf, matching the operating system's real terminal devices /dev/ttyu0 to /dev/ttyuf.
These are aliases for getty@ttyu0 through to getty@ttyuf.
These services invoke the FreeBSD /usr/libexec/getty program, with the getty class of std.9600.
The run script for such services is basically this (using getty@ttyu1 as an example):
#!/bin/nosh setsid /usr/libexec/getty std.9600 ttyu1
The services are ttylogin@tty00 through to ttylogin@tty07 and ttylogin@ttyU0 through to ttylogin@ttyU3, matching the operating system's real terminal devices /dev/tty00 to /dev/tty07 and /dev/ttyU0 to /dev/ttyU3.
These are aliases for getty@tty00 through to getty@tty07 and getty@ttyU0 through to getty@ttyU3.
These services invoke the OpenBSD /usr/libexec/getty program, with the getty class of std.9600.
The run script for such services is basically this (using getty@tty03 as an example):
#!/bin/nosh setsid /usr/libexec/getty std.9600 tty03
The services are ttylogin@ttyS0 through to ttylogin@ttyS3, matching the operating system's real terminal devices /dev/ttyS0 to /dev/ttyS3.
By default, these are aliases for agetty@ttyS0 through to agetty@ttyS3.
But they can if one wishes instead be aliased to mgetty@ttyS0 through to mgetty@ttyS3.
The first set of services invokes Wietse Venema's agetty program.
The run script for such services is basically this (using agetty@ttyS2 as an example):
#!/bin/nosh setsid agetty ttyS2
The second set of services invokes Gert Doering's mgetty program.
The run script for such services is basically this (using mgetty@ttyS0 as an example):
#!/bin/nosh mgetty ttyS0
Note:
Florian La Roche's mingetty program and Felix von Leitner's fgetty program are not suitable for use with real terminals attached to serial devices.