xref: /minix/libexec/getty/getty.8 (revision 84d9c625)
1.\"	$NetBSD: getty.8,v 1.18 2013/05/29 15:02:12 wiz Exp $
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30.\"     from: @(#)getty.8	8.1 (Berkeley) 6/4/93
31.\"
32.Dd May 29, 2013
33.Dt GETTY 8
34.Os
35.Sh NAME
36.Nm getty ,
37.Nm uugetty
38.Nd set terminal modes for system access
39.Sh SYNOPSIS
40.Nm
41.Oo
42.Ar type
43.Op Ar tty
44.Oc
45.Nm uugetty
46.Oo
47.Ar type
48.Op Ar tty
49.Oc
50.Sh DESCRIPTION
51The
52.Nm
53program
54is called by
55.Xr init 8
56to open and initialize the tty line, read a login name, and invoke
57.Xr login 1 .
58The devices on which to run
59.Nm
60are normally determined by
61.Xr ttys 5 .
62.Pp
63The
64.Nm
65program can also recognize a Point to Point Protocol
66.Pq Tn PPP
67negotiation, and, if the
68.Sy pp
69attribute in
70.Xr gettytab 5
71is set, invoke the program given by that string, e.g.,
72.Xr pppd 8 ,
73instead of
74.Xr login 1 .
75This makes it possible to use a single serial port for either a
76.Qq shell
77account with command line interface, or a
78.Tn PPP
79network link.
80.Pp
81The argument
82.Ar tty
83is the special device file in
84.Pa /dev
85to open for the terminal
86.Po
87for example,
88.Qq ttyh0
89.Pc .
90If there is no argument or the argument is
91.Ql Fl ,
92the tty line is assumed to be open as file descriptor 0.
93.Pp
94The
95.Ar type
96argument can be used to make
97.Nm
98treat the terminal line specially.
99This argument is used as an index into the
100.Xr gettytab 5
101database, to determine the characteristics of the line.
102If there is no argument, or there is no such table, the
103.Em default
104table is used.
105If there is no
106.Pa /etc/gettytab
107a set of system defaults is used.
108If indicated by the table located,
109.Nm
110will clear the terminal screen,
111print a banner heading,
112and prompt for a login name.
113Usually either the banner or the login prompt will include
114the system hostname.
115.Pp
116.Nm
117uses the
118.Xr ttyaction 3
119facility with an action of
120.Qq getty
121and user
122.Qq root
123to execute site-specific commands when it starts.
124.Pp
125Most of the default actions of
126.Nm
127can be circumvented, or modified, by a suitable
128.Xr gettytab 5
129table.
130.Pp
131The
132.Nm
133program can be set to timeout after some interval,
134which will cause dial up lines to hang up
135if the login name is not entered reasonably quickly.
136.Pp
137The
138.Nm uugetty
139program is the same, except that it uses
140.Xr pidlock 3
141to respect the locks in
142.Pa /var/spool/lock
143of processes that dial out on that tty.
144.Sh FILES
145.Bl -tag -width /var/spool/lock/LCK..ttyXX -compact
146.It Pa /etc/gettytab
147.It Pa /etc/ttys
148.It Pa /usr/libexec/getty
149.It Pa /var/spool/lock/LCK..ttyXX
150.El
151.Sh DIAGNOSTICS
152.Bl -diag
153.It "ttyxx: No such device or address."
154.It "ttyxx: No such file or address."
155A terminal which is turned on in the
156.Xr ttys 5
157file cannot be opened, likely because the requisite
158lines are either not configured into the system, the associated device
159was not attached during boot-time system configuration,
160or the special file in
161.Pa /dev
162does not exist.
163.El
164.Sh SEE ALSO
165.Xr login 1 ,
166.Xr ioctl 2 ,
167.Xr pidlock 3 ,
168.Xr ttyaction 3 ,
169.Xr tty 4 ,
170.Xr gettytab 5 ,
171.Xr ttys 5 ,
172.Xr init 8 ,
173.Xr pppd 8
174.Sh HISTORY
175A
176.Nm
177program appeared in
178.At v6 .
179