[unix-history] / usr / src / usr.bin / login / login.1

.\" Copyright (c) 1980, 1990 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"	@(#)login.1	6.12 (Berkeley) 6/29/91
.\"
.Dd June 29, 1991
.Dt LOGIN 1
.Os BSD 4
.Sh NAME
.Nm login
.Nd log into the computer
.Sh SYNOPSIS
.Nm login
.Op Fl fp
.Op Fl h Ar hostname
.Op Ar user
.Sh DESCRIPTION
The
.Nm login
utility logs users (and pseudo-users) into the computer system.
.Pp
If no user is specified, or if a user is specified and authentication
of the user fails,
.Nm login
prompts for a user name.
Authentication of users is done via passwords.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl f
The
.Fl f
option is used when a user name is specified to indicate that proper
authentication has already been done and that no password need be
requested.
This option may only be used by the super-user or when an already
logged in user is logging in as themselves.
.It Fl h
The
.Fl h
option specifies the host from which the connection was received.
It is used by various daemons such as
.Xr telnetd  8 .
This option may only be used by the super-user.
.It Fl p
By default,
.Nm login
discards any previous environment.
The
.Fl p
option disables this behavior.
.El
.Pp
If the file
.Pa /etc/nologin
exists,
.Nm login
dislays its contents to the user and exits.
This is used by
.Xr shutdown  8
to prevent users from logging in when the system is about to go down.
.Pp
Immediately after logging a user in,
.Nm login
displays the system copyright notice, the date and time the user last
logged in, the message of the day as well as other information.
If the file
.Dq Pa .hushlogin
exists in the user's home directory, all of these messages are suppressed.
This is to simplify logins for non-human users, such as
.Xr uucp 1 .
.Nm Login
then records an entry in the
.Xr wtmp 5
and
.Xr utmp 5
files and executes the user's command interpretor.
.Pp
Login enters information into the environment (see
.Xr environ 7 )
specifying the user's home directory (HOME), command interpreter (SHELL),
search path (PATH), terminal type (TERM) and user name (both LOGNAME and
USER).
.Pp
The standard shells,
.Xr csh 1
and
.Xr sh 1 ,
do not fork before executing the
.Nm login
utility.
.Sh FILES
.Bl -tag -width /var/mail/userXXX -compact
.It Pa /etc/motd
message-of-the-day
.It Pa /etc/nologin
disallows logins
.It Pa /var/run/utmp
current logins
.It Pa /var/log/wtmp
login account records
.It Pa /var/mail/user
system mailboxes
.It Pa \&.hushlogin
makes login quieter
.El
.Sh SEE ALSO
.Xr chpass 1 ,
.Xr passwd 1 ,
.Xr rlogin 1 ,
.Xr getpass 3 ,
.Xr utmp 5 ,
.Xr environ 7 ,
.Sh HISTORY
A
.Nm login
appeared in
.At v6 .
Commit	Line	Data
8eaae950 WJ	1	.\" Copyright (c) 1980, 1990 The Regents of the University of California.
	2	.\" All rights reserved.
	3	.\"
	4	.\" Redistribution and use in source and binary forms, with or without
	5	.\" modification, are permitted provided that the following conditions
	6	.\" are met:
	7	.\" 1. Redistributions of source code must retain the above copyright
	8	.\" notice, this list of conditions and the following disclaimer.
	9	.\" 2. Redistributions in binary form must reproduce the above copyright
	10	.\" notice, this list of conditions and the following disclaimer in the
	11	.\" documentation and/or other materials provided with the distribution.
	12	.\" 3. All advertising materials mentioning features or use of this software
	13	.\" must display the following acknowledgement:
	14	.\" This product includes software developed by the University of
	15	.\" California, Berkeley and its contributors.
	16	.\" 4. Neither the name of the University nor the names of its contributors
	17	.\" may be used to endorse or promote products derived from this software
	18	.\" without specific prior written permission.
	19	.\"
	20	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	21	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	24	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	.\" SUCH DAMAGE.
	31	.\"
	32	.\" @(#)login.1 6.12 (Berkeley) 6/29/91
	33	.\"
	34	.Dd June 29, 1991
	35	.Dt LOGIN 1
	36	.Os BSD 4
	37	.Sh NAME
	38	.Nm login
	39	.Nd log into the computer
	40	.Sh SYNOPSIS
	41	.Nm login
	42	.Op Fl fp
	43	.Op Fl h Ar hostname
	44	.Op Ar user
	45	.Sh DESCRIPTION
	46	The
	47	.Nm login
	48	utility logs users (and pseudo-users) into the computer system.
	49	.Pp
	50	If no user is specified, or if a user is specified and authentication
	51	of the user fails,
	52	.Nm login
	53	prompts for a user name.
	54	Authentication of users is done via passwords.
	55	.Pp
	56	The options are as follows:
	57	.Bl -tag -width Ds
	58	.It Fl f
	59	The
	60	.Fl f
	61	option is used when a user name is specified to indicate that proper
	62	authentication has already been done and that no password need be
	63	requested.
	64	This option may only be used by the super-user or when an already
65	logged in user is logging in as themselves.
66	.It Fl h
67	The
68	.Fl h
69	option specifies the host from which the connection was received.
70	It is used by various daemons such as
71	.Xr telnetd 8 .
72	This option may only be used by the super-user.
73	.It Fl p
74	By default,
75	.Nm login
76	discards any previous environment.
77	The
78	.Fl p
79	option disables this behavior.
80	.El
81	.Pp
82	If the file
83	.Pa /etc/nologin
84	exists,
85	.Nm login
86	dislays its contents to the user and exits.
87	This is used by
88	.Xr shutdown 8
89	to prevent users from logging in when the system is about to go down.
90	.Pp
91	Immediately after logging a user in,
92	.Nm login
93	displays the system copyright notice, the date and time the user last
94	logged in, the message of the day as well as other information.
95	If the file
96	.Dq Pa .hushlogin
97	exists in the user's home directory, all of these messages are suppressed.
98	This is to simplify logins for non-human users, such as
99	.Xr uucp 1 .
100	.Nm Login
101	then records an entry in the
102	.Xr wtmp 5
103	and
104	.Xr utmp 5
105	files and executes the user's command interpretor.
106	.Pp
107	Login enters information into the environment (see
108	.Xr environ 7 )
109	specifying the user's home directory (HOME), command interpreter (SHELL),
110	search path (PATH), terminal type (TERM) and user name (both LOGNAME and
111	USER).
112	.Pp
113	The standard shells,
114	.Xr csh 1
115	and
116	.Xr sh 1 ,
117	do not fork before executing the
118	.Nm login
119	utility.
120	.Sh FILES
121	.Bl -tag -width /var/mail/userXXX -compact
122	.It Pa /etc/motd
123	message-of-the-day
124	.It Pa /etc/nologin
125	disallows logins
126	.It Pa /var/run/utmp
127	current logins
128	.It Pa /var/log/wtmp
129	login account records
130	.It Pa /var/mail/user
131	system mailboxes
132	.It Pa \&.hushlogin
133	makes login quieter
134	.El
135	.Sh SEE ALSO
136	.Xr chpass 1 ,
137	.Xr passwd 1 ,
138	.Xr rlogin 1 ,
139	.Xr getpass 3 ,
140	.Xr utmp 5 ,
141	.Xr environ 7 ,
142	.Sh HISTORY
143	A
144	.Nm login
145	appeared in
146	.At v6 .