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><H1
CLASS="SECT1"
><A
NAME="SHUTTING-DOWN"
></A
>Shutting Down/Rebooting the System</H1
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
>shutdown&nbsp;now</DT
><DD
><P
><A
NAME="AEN5159"
></A
>Shutdown the computer immediately (don't power down<A
NAME="AEN5161"
></A
>). Note that in <SPAN
CLASS="PRODUCTNAME"
>UNIX</SPAN
> <A
NAME="AEN5164"
></A
>systems this kind of shutdown <A
NAME="AEN5166"
></A
>means to go to &ldquo; single-user mode&rdquo;.<A
NAME="AEN5168"
></A
><A
NAME="AEN5170"
></A
> Single-user mode is a mode where only the administrator <A
NAME="AEN5172"
></A
>(root) has access<A
NAME="AEN5174"
></A
> to the computer, this mode <A
NAME="AEN5176"
></A
>is designed <A
NAME="AEN5178"
></A
>for maintenance <A
NAME="AEN5180"
></A
>and is often used for repairs.<A
NAME="AEN5182"
></A
></P
><P
>For example this would take you to single user mode </P
><PRE
CLASS="SCREEN"
>shutdown now</PRE
></DD
><DT
>shutdown&nbsp;-h&nbsp;now</DT
><DD
><P
><A
NAME="AEN5190"
></A
>Shutdown <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>(-h<A
NAME="AEN5193"
></A
> = halt) </I
></SPAN
>the computer immediately. It begins the shutdown procedure,<A
NAME="AEN5195"
></A
> press
<B
CLASS="KEYCAP"
>CTRL</B
>-<B
CLASS="KEYCAP"
>C</B
>
<A
NAME="AEN5200"
></A
>
(break-key) to stop <A
NAME="AEN5202"
></A
>it. After the end of the command you can also leave a message <A
NAME="AEN5204"
></A
>in quotation<A
NAME="AEN5206"
></A
> marks <A
NAME="AEN5208"
></A
>which will be broad-casted <A
NAME="AEN5210"
></A
>to all users, for example:</P
><PRE
CLASS="SCREEN"
>shutdown -h now "Warning system malfunction, self-destruct imminent"</PRE
><P
>This would halt <A
NAME="AEN5214"
></A
>the system and send <A
NAME="AEN5216"
></A
>the message <A
NAME="AEN5218"
></A
>to anyone who <A
NAME="AEN5220"
></A
>is currently logged<A
NAME="AEN5222"
></A
> in.</P
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>Shutting down at a particular time: </B
>You can also put a time that the system should shutdown instead of &ldquo;now&rdquo;. Typing &ldquo;+x minutes<A
NAME="AEN5227"
></A
>&rdquo; (any number <A
NAME="AEN5229"
></A
>of minutes <A
NAME="AEN5231"
></A
>is appropriate) or you can even set an exact <A
NAME="AEN5233"
></A
>time. For example to shutdown <A
NAME="AEN5235"
></A
>at <A
NAME="AEN5237"
></A
>11:50 type:
<PRE
CLASS="SCREEN"
>shutdown -h 11:50</PRE
></P
></BLOCKQUOTE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Shutdown -h vs poweroff: </B
>On some systems, <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>shutdown -h </I
></SPAN
>and <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>halt </I
></SPAN
>do not actually turn the system's power off. On systems that do not power off with these commands use the <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>poweroff</I
></SPAN
><A
NAME="AEN5246"
></A
> command</P
></BLOCKQUOTE
></DIV
></DD
><DT
>halt</DT
><DD
><P
><A
NAME="AEN5252"
></A
>The same as <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>shutdown -h now</I
></SPAN
> doesn't take any options,<A
NAME="AEN5255"
></A
> this command simply shuts down immediately.</P
></DD
><DT
>shutdown&nbsp;-r&nbsp;now</DT
><DD
><P
><A
NAME="AEN5261"
></A
>Shutdown (<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
> -r <A
NAME="AEN5264"
></A
>= reboot<A
NAME="AEN5266"
></A
></I
></SPAN
>) the computer immediately. It begins the reboot procedure,<A
NAME="AEN5268"
></A
> press <A
NAME="AEN5270"
></A
>
<B
CLASS="KEYCAP"
>CTRL</B
>-<B
CLASS="KEYCAP"
>C</B
>
<A
NAME="AEN5275"
></A
>
(break-key) to stop <A
NAME="AEN5277"
></A
>it. After the end of the command you can also leave a message <A
NAME="AEN5279"
></A
>in quotation<A
NAME="AEN5281"
></A
> marks <A
NAME="AEN5283"
></A
>which will be broad-casted <A
NAME="AEN5285"
></A
>to all users, for example: </P
><PRE
CLASS="SCREEN"
>shutdown -r now "Warning system rebooting, all files will be destroyed"</PRE
><P
>This would reboot the system and send <A
NAME="AEN5289"
></A
>the message <A
NAME="AEN5291"
></A
>to anyone who <A
NAME="AEN5293"
></A
>was logged in.</P
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>Rebooting at a particular time: </B
>You can also put a time that the system should reboot instead of &ldquo;now&rdquo;. Typing &ldquo;+x minutes<A
NAME="AEN5298"
></A
>&rdquo; (any number of minutes <A
NAME="AEN5300"
></A
>is appropriate) or you can even set <A
NAME="AEN5302"
></A
>an exact <A
NAME="AEN5304"
></A
>time. For example to reboot <A
NAME="AEN5306"
></A
>at 11:50 type:
<PRE
CLASS="SCREEN"
>shutdown -r 11:50</PRE
></P
></BLOCKQUOTE
></DIV
></DD
><DT
>reboot</DT
><DD
><P
>The same as <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>shutdown -r now</I
></SPAN
>, doesn't take any options, simply reboots <A
NAME="AEN5314"
></A
>the computer immediately. </P
></DD
><DT
><B
CLASS="KEYCAP"
>CTRL</B
>-<B
CLASS="KEYCAP"
>ALT</B
>-<B
CLASS="KEYCAP"
>DEL</B
>
<A
NAME="AEN5322"
></A
></DT
><DD
><P
> (key-combination) May be used from a terminal <A
NAME="AEN5326"
></A
>to reboot or shutdown,<A
NAME="AEN5328"
></A
> it depends on your system configuration. Note that this doesn't work from an xterminal.<A
NAME="AEN5330"
></A
>
<B
CLASS="KEYCAP"
>CTRL</B
>-<B
CLASS="KEYCAP"
>ALT</B
>-<B
CLASS="KEYCAP"
>DEL</B
>
<A
NAME="AEN5336"
></A
>
begins the reboot/shutdown immediately, the user does not have to be logged in.</P
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>You can change the behaviour of
<B
CLASS="KEYCAP"
>CTRL</B
>-<B
CLASS="KEYCAP"
>ALT</B
>-<B
CLASS="KEYCAP"
>DEL</B
>
<A
NAME="AEN5344"
></A
>
from rebooting: </B
>To disable
<B
CLASS="KEYCAP"
>CTRL</B
>-<B
CLASS="KEYCAP"
>ALT</B
>-<B
CLASS="KEYCAP"
>DEL</B
>
<A
NAME="AEN5351"
></A
>
from rebooting your computer (or to have it do something different), you can edit the /etc/inittab<A
NAME="AEN5353"
></A
> file (as root). </P
><P
>Here is how it looks on a Mandrake/Mandriva <SPAN
CLASS="PRODUCTNAME"
>Linux</SPAN
> system:
<PRE
CLASS="SCREEN"
># Trap
<B
CLASS="KEYCAP"
>CTRL</B
>-<B
CLASS="KEYCAP"
>ALT</B
>-<B
CLASS="KEYCAP"
>DEL</B
>
<A
NAME="AEN5362"
></A
>
ca::ctrlaltdel:/sbin/shutdown -t3 -r now </PRE
></P
><P
>Note that the # means a comment (and is not used). If you simply put a # (hash) before the command it would disable it (it would become a comment). </P
><P
>You could also change the command it runs for example if you changed the <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>-r</I
></SPAN
> to a <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>-h </I
></SPAN
>the computer would turn off instead of rebooting, or you could have it do anything you want. It's up to your creativity to make it do something interesting.</P
></BLOCKQUOTE
></DIV
></DD
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