NAME
getty,
uugetty —
set
terminal modes for system access
SYNOPSIS
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
-
- /usr/libexec/getty
-
- /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.