projects / unix-history / blame
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|---|---|---|
| 7ead89cf KM |
1 | .\" Copyright (c) 1980 Regents of the University of California. |
| 2 | .\" All rights reserved. The Berkeley software License Agreement | |
| 3 | .\" specifies the terms and conditions for redistribution. | |
| 4 | .\" | |
| cccdca83 | 5 | .\" @(#)shutdown.8 5.1 (Berkeley) %G% |
| 7ead89cf | 6 | .\" |
| cccdca83 | 7 | .TH SHUTDOWN 8 4/1/83 |
| 7ead89cf KM |
8 | .UC 4 |
| 9 | .SH NAME | |
| 10 | shutdown \- close down the system at a given time | |
| 11 | .SH SYNOPSIS | |
| 12 | .B /etc/shutdown | |
| 13 | [ | |
| 14 | .B \-k | |
| 15 | ] [ | |
| 16 | .B \-r | |
| 17 | ] [ | |
| 18 | .B \-h | |
| 19 | ] | |
| 20 | time [ warning-message ... ] | |
| 21 | .SH DESCRIPTION | |
| 22 | .I Shutdown | |
| 23 | provides an automated shutdown procedure which a super-user | |
| 24 | can use to notify users | |
| 25 | nicely when the system is shutting down, saving them from | |
| 26 | system administrators, hackers, and gurus, who would otherwise | |
| 27 | not bother with niceties. | |
| 28 | .LP | |
| 29 | .I Time | |
| 30 | is the time at which | |
| 31 | .I shutdown | |
| 32 | will bring the system down and | |
| cccdca83 KM |
33 | may be the word |
| 34 | .B now | |
| 35 | (indicating an immediate shutdown) | |
| 36 | or specify a future time in one of two formats: | |
| 7ead89cf KM |
37 | .BR + number |
| 38 | and | |
| 39 | .RB hour : min. | |
| 40 | The first form brings the system down in | |
| 41 | .I number | |
| 42 | minutes | |
| 43 | and the second brings the system down at the time of day indicated | |
| 44 | (as a 24\-hour clock). | |
| 45 | .PP | |
| 46 | At intervals which get closer together as apocalypse approaches, | |
| 47 | warning messages are displayed at the terminals of all users on the | |
| 48 | system. Five minutes before shutdown, or immediately if | |
| 49 | shutdown is in less than 5 minutes, logins are disabled by | |
| 50 | creating | |
| 51 | /etc/nologin | |
| 52 | and writing a message there. | |
| cccdca83 | 53 | If this file exists when a user attempts to log in, |
| 7ead89cf KM |
54 | .IR login (1) |
| 55 | prints its contents | |
| 56 | and exits. | |
| 57 | The file is removed just before | |
| 58 | .I shutdown | |
| 59 | exits. | |
| 60 | .PP | |
| 61 | At shutdown time a | |
| 62 | message is written in the file /usr/adm/shutdownlog, containing the | |
| 63 | time of shutdown, who ran shutdown and the reason. | |
| 64 | Then a terminate signal is sent at | |
| 65 | .I init | |
| 66 | to bring the system down to single-user state. | |
| 67 | Alternatively, if | |
| cccdca83 KM |
68 | .B \-r, |
| 69 | .B \-h, | |
| 7ead89cf | 70 | or |
| cccdca83 | 71 | .B \-k |
| 7ead89cf KM |
72 | was used, then |
| 73 | .I shutdown | |
| 74 | will exec | |
| 75 | .IR reboot (8), | |
| 76 | .IR halt (8), | |
| 77 | or avoid shutting the system down (respectively). | |
| 78 | (If it isn't obvious, | |
| 79 | .B \-k | |
| 80 | is to make people | |
| 81 | .I think | |
| 82 | the system is going down!) | |
| 83 | .PP | |
| 84 | The time of the shutdown and the warning message | |
| 85 | are placed in /etc/nologin and should be used to | |
| 86 | inform the users about when the system will be back up | |
| 87 | and why it is going down (or anything else). | |
| 88 | .SH FILES | |
| 89 | .DT | |
| 90 | /etc/nologin tells login not to let anyone log in | |
| 91 | .br | |
| cccdca83 | 92 | /usr/adm/shutdownlog log file for successful shutdowns. |
| 7ead89cf KM |
93 | .SH "SEE ALSO" |
| 94 | login(1), reboot(8) | |
| 95 | .SH BUGS | |
| 96 | Only allows you to kill the system between now and 23:59 if | |
| 97 | you use the absolute time for shutdown. |