login.tproj/login.1

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  32 .\"     @(#)login.1     8.2 (Berkeley) 5/5/94
  33 .\" $FreeBSD: src/usr.bin/login/login.1,v 1.33 2007/11/30 11:02:36 philip Exp $
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  35 .Dd September 13, 2006
  36 .Dt LOGIN 1
  37 .Os
  38 .Sh NAME
  39 .Nm login
  40 .Nd log into the computer
  41 .Sh SYNOPSIS
  42 .Nm
  43 .Op Fl pq
  44 .Op Fl h Ar hostname
  45 .Op Ar user
  46 .Nm
  47 .Fl f
  48 .Op Fl lpq
  49 .Op Fl h Ar hostname
  50 .Op Ar user Op Ar prog Op Ar args...
  51 .Sh DESCRIPTION
  52 The
  53 .Nm
  54 utility logs users (and pseudo-users) into the computer system.
  55 .Pp
  56 If no user is specified, or if a user is specified and authentication
  57 of the user fails,
  58 .Nm
  59 prompts for a user name.
  60 Authentication of users is configurable via
  61 .Xr pam 8 .
  62 Password authentication is the default.
  63 .Pp
  64 The following options are available:
  65 .Bl -tag -width indent
  66 .It Fl f
  67 When a user name is specified, this option indicates that proper
  68 authentication has already been done and that no password need be
  69 requested.
  70 This option may only be used by the super-user or when an already
  71 logged in user is logging in as themselves.
  72 .Pp
  73 With the
  74 .Fl f
  75 option, an alternate program (and any arguments) may be run instead of the
  76 user's default shell.
  77 The program and arguments follows the user name.
  78 .It Fl h
  79 Specify the host from which the connection was received.
  80 It is used by various daemons such as
  81 .Xr telnetd 8 .
  82 This option may only be used by the super-user.
  83 .It Fl l
  84 Tells the program executed by
  85 .Nm
  86 that this is not a login session (by convention, a login session is
  87 signalled to the program with a hyphen as the first character of
  88 .Em argv[0] ;
  89 this option disables that), and prevents it from chdir(2)ing to the user's home directory.
  90 The default is to add the hyphen (this is a login session).
  91 .It Fl p
  92 By default,
  93 .Nm
  94 discards any previous environment.
  95 The
  96 .Fl p
  97 option disables this behavior.
  98 .It Fl q
  99 This forces quiet logins, as if a
 100 .Pa .hushlogin
 101 is present.
 102 .El
 103 .Pp
 104 If the file
 105 .Pa /etc/nologin
 106 exists,
 107 .Nm
 108 dislays its contents to the user and exits.
 109 This is used by
 110 .Xr shutdown  8
 111 to prevent users from logging in when the system is about to go down.
 112 .Pp
 113 Immediately after logging a user in,
 114 .Nm
 115 displays the system copyright notice, the date and time the user last
 116 logged in, the message of the day as well as other information.
 117 If the file
 118 .Pa .hushlogin
 119 exists in the user's home directory, all of these messages are suppressed.
 120 .Fl q
 121 is specified, all of these messages are suppressed.
 122 This is to simplify logins for non-human users, such as
 123 .Xr uucp 1 .
 124 .Nm
 125 then records an entry in
 126 .Xr utmpx 5
 127 and the like, and executes the user's command interpreter (or the program
 128 specified on the command line if
 129 .Fl f
 130 is specified).
 131 .Pp
 132 The
 133 .Nm
 134 utility enters information into the environment (see
 135 .Xr environ 7 )
 136 specifying the user's home directory (HOME), command interpreter (SHELL),
 137 search path (PATH), terminal type (TERM) and user name (both LOGNAME and
 138 USER).
 139 .Pp
 140 Some shells may provide a builtin
 141 .Nm
 142 command which is similar or identical to this utility.
 143 Consult the
 144 .Xr builtin 1
 145 manual page.
 146 .Pp
 147 The
 148 .Nm
 149 utility will submit an audit record when login succeeds or fails.
 150 Failure to determine the current auditing state will
 151 result in an error exit from
 152 .Nm .
 153 .Sh FILES
 154 .Bl -tag -width /var/mail/userXXX -compact
 155 .It Pa /etc/motd
 156 message-of-the-day
 157 .It Pa /etc/nologin
 158 disallows logins
 159 .It Pa /var/run/utmpx
 160 current logins
 161 .It Pa /var/mail/user
 162 system mailboxes
 163 .It Pa \&.hushlogin
 164 makes login quieter
 165 .It Pa /etc/pam.d/login
 166 .Xr pam 8
 167 configuration file
 168 .It Pa /etc/security/audit_user
 169 user flags for auditing
 170 .It Pa /etc/security/audit_control
 171 global flags for auditing
 172 .El
 173 .Sh SEE ALSO
 174 .Xr builtin 1 ,
 175 .Xr chpass 1 ,
 176 .Xr newgrp 1 ,
 177 .Xr passwd 1 ,
 178 .Xr rlogin 1 ,
 179 .Xr getpass 3 ,
 180 .Xr utmpx 5 ,
 181 .Xr environ 7
 182 .Sh HISTORY
 183 A
 184 .Nm
 185 utility appeared in
 186 .At v6 .