getty - set terminal mode
getty [ type [ tty ] ]
Getty is usually invoked by init(8) to open and initialize the tty line, read a login
name, and invoke login(1). getty attempts to adapt the system to the speed and type of
terminal being used.
The argument tty is the special device file in /dev to open for the terminal (e.g.,
``ttyh0''). If there is no argument or the argument is ``-'', the tty line is assumed to
be open as file descriptor 0.
The type argument can be used to make getty treat the terminal line specially. This argu-
ment is used as an index into the gettytab(5) database, to determine the characteristics
of the line. If there is no argument, or there is no such table, the default table is
used. If there is no /etc/gettytab 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 of the login prompt will include the system
hostname. Then the user's name is read, a character at a time. If a null character is
received, it is assumed to be the result of the user pushing the `break' (`interrupt')
key. The speed is usually then changed and the `login:' is typed again; a second `break'
changes the speed again and the `login:' is typed once more. Successive `break' charac-
ters cycle through the same standard set of speeds.
The user's name is terminated by a new-line 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 lower-case alphabetic characters; if
not, and if the name is nonempty, the system is told to map any future upper-case charac-
ters into the corresponding lower-case characters.
Finally, login is called with the user's name as an argument.
Most of the default actions of getty can be circumvented, or modified, by a suitable get-
Getty can be set to timeout after some interval, which will cause dial up lines to hang up
if the login name is not entered reasonably quickly.
ttyxx: No such device or address. ttyxx: No such file or address. A terminal which is
turned on in the ttys file cannot be opened, likely because the requisite lines are either
not configured into the system, the associated device was not attached during boot-time
system configuration, or the special file in /dev does not exist.
gettytab(5), init(8), login(1), ioctl(2), tty(4), ttys(5)
4th Berkeley Distribution November 17, 1996 GETTY(8)