NAME
getty - set terminal mode

SYNOPSIS
/etc/getty [ type [ tty ] ]

DESCRIPTION
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 argument 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 or 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’ characters 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 characters 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 gettytab table.

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.

DIAGNOSTICS
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.

FILES
/etc/gettytab

SEE ALSO
gettytab(5), init(8), login(1), ioctl(2), tty(4), ttys(5)

BUGS
If a user id (in /etc/passwd) has all capital letters, login
confuses the response to the login request as input coming from a
terminal with capital letters only. This causes all output to the
terminal to be in capitals and havoc ensues.