NAME

getty, uugetty — set terminal modes for system access

SYNOPSIS

getty

[type [tty]]

uugetty

[type [tty]]

DESCRIPTION

The getty program is called by init(8) to open and initialize the tty line, read a login name, and invoke login(1). The devices on which to run getty are normally determined by ttys(5).

The getty program can also recognize a Point to Point Protocol (PPP) negotiation, and, if the pp attribute in gettytab(5) is set, invoke the program given by that string, e.g., pppd(8), instead of login(1). This makes it possible to use a single serial port for either a “shell” account with command line interface, or a PPP network link.

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 ‘-', 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.

getty uses the ttyaction(3) facility with an action of “getty” and user “root” to execute site-specific commands when it starts.

Most of the default actions of getty can be circumvented, or modified, by a suitable gettytab(5) table.

The getty program 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.

The uugetty program is the same, except that it uses pidlock(3) to respect the locks in /var/spool/lock of processes that dial out on that tty.

FILES

/etc/gettytab

/etc/ttys

/var/spool/lock/LCK..ttyXX

DIAGNOSTICS

ttyxx: No such device or address.

ttyxx: No such file or address.

A terminal which is turned on in the ttys(5) 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.

SEE ALSO

login(1), ioctl(2), pidlock(3), ttyaction(3), tty(4), gettytab(5), ttys(5), init(8), pppd(8)

HISTORY

A getty program appeared in Version 6 AT&T UNIX.