GETTY(8) — UNIX Programmer’s Manual
NAME
getty − set terminal mode
SYNOPSIS
/etc/getty [ type ]
DESCRIPTION
Getty attempts to adapt the system to the type of terminal being used. Getty is called by init(8) immediately after making a connection. Init first reads the entry in the /etc/ttys file for the terminal line being opened and then calls getty, passing the second character in the entry as an argument. Getty uses this character to select an entry from the /etc/gettytab file. This entry describes characteristics of the terminal, including its baud rate. If there is no argument or no such table, the default table is used. If there is no /etc/gettytab file, a set of system defaults is used.
If indicated by the table located, getty will clear the terminal screen, print a banner heading, and prompt for a login name. Usually either the banner or the login prompt will include the system hostname. Then the user’s name is read, one character at a time. If a null character is received, it is assumed to be the result of the user having pushed the break (interrupt) key. The speed is usually changed and the login is typed again; a second break changes the speed again and the login is typed once more. Successive break characters cycle through the same standard set of speeds.
The user’s name is terminated by a newline or carriage-return character. The latter results in the system being set to treat carriage returns appropriately (see tty(4)).
The user’s name is scanned to see if it contains any lowercase alphabetic characters; if not, and if the name is nonempty, the system is told to map any future uppercase characters into the corresponding lowercase characters.
Finally, login is called with the user’s name as argument.
Most of the default actions of getty can be circumvented, or modified, by a suitable gettytab table.
Getty can be set to time out after an interval; if the login name is not entered within a reasonable amount of time, the dial-up lines will hang up.
FILES
/etc/gettytab
SEE ALSO
gettytab(5), init(8), login(1), ioctl(2), tty(4), ttys(5)
DYNIX System Administration Guide
BUGS
Currently, the format of /etc/ttys limits the permitted table names to a single character; this should be expanded.
/etc/ttys should be replaced completely.
4BSD