getty(8) — bsd

GETTY(8)                             BSD                              GETTY(8)



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 (for example, ttyh0).  If there is no argument or the argument
     is a dash (-), 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, one character at a time.  If a null character is received, it is
     assumed to be the result of the user typing the break (interrupt)
     character.  The speed is usually then changed and the login prompt is
     typed again; a second "break" changes the speed again and the login
     prompt 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 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."  A terminal which is turned on in the
     ttys file cannot be opened, probably 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);
     Using Your BSD Environment.
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