shutdown.tproj/shutdown.8

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  32 .\"     @(#)shutdown.8  8.2 (Berkeley) 4/27/95
  33 .\"
  34 .Dd April 27, 1995
  35 .Dt SHUTDOWN 8
  36 .Os BSD 4
  37 .Sh NAME
  38 .Nm shutdown
  39 .Nd "close down the system at a given time"
  40 .Sh SYNOPSIS
  41 .Nm shutdown
  42 .Op Fl
  43 .Op Fl fhkrn
  44 .Ar time
  45 .Op Ar warning-message ...
  46 .Sh DESCRIPTION
  47 .Nm Shutdown
  48 provides an automated shutdown procedure for super-users
  49 to nicely notify users when the system is shutting down,
  50 saving them from system administrators, hackers, and gurus, who
  51 would otherwise not bother with such niceties.
  52 .Pp
  53 Available friendlinesses:
  54 .Bl -tag -width time
  55 .It Fl f
  56 .Nm Shutdown
  57 arranges, in the manner of
  58 .Xr fastboot 8 ,
  59 for the file systems
  60 .Em not to be
  61 checked on reboot.
  62 .It Fl h
  63 The system is halted at the specified
  64 .Ar time
  65 when
  66 .Nm shutdown
  67 execs
  68 .Xr halt 8 .
  69 .It Fl k
  70 Kick everybody off.
  71 The
  72 .Fl k
  73 option
  74 does not actually halt the system, but leaves the
  75 system multi-user with logins disabled (for all but super-user).
  76 .It Fl n
  77 Prevent the normal
  78 .Xr sync 2
  79 before stopping.
  80 .It Fl r
  81 .Nm Shutdown
  82 execs
  83 .Xr reboot 8
  84 at the specified
  85 .Ar time .
  86 .It Ar time
  87 .Ar Time
  88 is the time at which
  89 .Nm shutdown
  90 will bring the system down and
  91 may be the word
  92 .Ar now
  93 (indicating an immediate shutdown) or
  94 specify a future time in one of two formats:
  95 .Ar +number ,
  96 or
  97 .Ar yymmddhhmm ,
  98 where the year, month, and day may be defaulted
  99 to the current system values.  The first form brings the system down in
 100 .Ar number
 101 minutes and the second at the absolute time specified.
 102 .It Ar warning-message
 103 Any other arguments comprise the warning message that is broadcast
 104 to users currently logged into the system.
 105 .It Fl
 106 If
 107 .Ql Fl
 108 is supplied as an option, the warning message is read from the standard
 109 input.
 110 .El
 111 .Pp
 112 At intervals, becoming more frequent as apocalypse approaches
 113 and starting at ten hours before shutdown, warning messages are displayed
 114 on the terminals of all users logged in.  Five minutes before
 115 shutdown, or immediately if shutdown is in less than 5 minutes,
 116 logins are disabled by creating
 117 .Pa /etc/nologin
 118 and copying the
 119 warning message there.  If this file exists when a user attempts to
 120 log in,
 121 .Xr login 1
 122 prints its contents and exits.  The file is
 123 removed just before
 124 .Nm shutdown
 125 exits.
 126 .Pp
 127 At shutdown time a message is written in the system log, containing the
 128 time of shutdown, who initiated the shutdown and the reason.
 129 A terminate
 130 signal is then sent to
 131 .Xr init
 132 to bring the system down to single-user state (depending on above
 133 options).
 134 The time of the shutdown and the warning message
 135 are placed in
 136 .Pa /etc/nologin
 137 and should be used to
 138 inform the users about when the system will be back up
 139 and why it is going down (or anything else).
 140 .Sh FILES
 141 .Bl -tag -width /etc/nologin -compact
 142 .It Pa /etc/nologin
 143 tells login not to let anyone log in
 144 .It Pa /fastboot
 145 tells
 146 .Xr rc 8
 147 not to run fsck when rebooting
 148 .El
 149 .Sh SEE ALSO
 150 .Xr login 1 ,
 151 .Xr wall 1 ,
 152 .Xr fastboot 8 ,
 153 .Xr halt 8 ,
 154 .Xr reboot 8
 155 .Sh BACKWARD COMPATIBILITY
 156 The hours and minutes in the second time format may be separated by
 157 a colon (``:'') for backward compatibility.
 158 .Sh HISTORY
 159 The
 160 .Nm
 161 command appeared in
 162 .Bx 4.0 .