lfs-book/chapter06/sysvinit.xml

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<sect1 id="ch-system-sysvinit" role="wrap">
<title>Sysvinit-&sysvinit-version;</title>
<?dbhtml filename="sysvinit.html"?>

<indexterm zone="ch-system-sysvinit"><primary sortas="a-Sysvinit">Sysvinit</primary></indexterm>

<sect2 role="package"><title/>
<para>The Sysvinit package contains programs for controlling the startup,
running, and shutdown of the system.</para>

<segmentedlist>
<segtitle>&buildtime;</segtitle>
<segtitle>&diskspace;</segtitle>
<seglistitem><seg>0.1 SBU</seg><seg>1012 KB</seg></seglistitem>
</segmentedlist>

<segmentedlist>
<segtitle>&dependencies;</segtitle>
<seglistitem><seg>Binutils, Coreutils, GCC, Glibc, and Make</seg></seglistitem>
</segmentedlist>
</sect2>

<sect2 role="installation">
<title>Installation of Sysvinit</title>

<para>When run-levels are changed (for example, when halting the
system), <command>init</command> sends termination signals to those
processes that <command>init</command> itself started and that should
not be running in the new run-level.  While doing this,
<command>init</command> outputs messages like <quote>Sending processes
the TERM signal</quote> which seem to imply that it is sending these
signals to all currently running processes. To avoid this
misinterpretation, modify the source so that these messages read like
<quote>Sending processes started by init the TERM signal</quote>
instead:</para>

<screen><userinput>sed -i 's@Sending processes@&amp; started by init@g' \
    src/init.c</userinput></screen>

<para>Compile the package:</para>

<screen><userinput>make -C src</userinput></screen>

<para>This package does not come with a test suite.</para>

<para>Install the package:</para>

<screen><userinput>make -C src install</userinput></screen>

</sect2>


<sect2 id="conf-sysvinit" role="configuration"><title>Configuring Sysvinit</title>
<indexterm zone="conf-sysvinit">
<primary sortas="a-Sysvinit">Sysvinit</primary>
<secondary>configuring</secondary></indexterm>

<indexterm zone="conf-sysvinit"><primary sortas="e-/etc/inittab">/etc/inittab</primary></indexterm>

<para>Create a new file <filename>/etc/inittab</filename> by running the
following:</para>

<screen><userinput>cat &gt; /etc/inittab &lt;&lt; "EOF"
<literal># Begin /etc/inittab

id:3:initdefault:

si::sysinit:/etc/rc.d/init.d/rc sysinit

l0:0:wait:/etc/rc.d/init.d/rc 0
l1:S1:wait:/etc/rc.d/init.d/rc 1
l2:2:wait:/etc/rc.d/init.d/rc 2
l3:3:wait:/etc/rc.d/init.d/rc 3
l4:4:wait:/etc/rc.d/init.d/rc 4
l5:5:wait:/etc/rc.d/init.d/rc 5
l6:6:wait:/etc/rc.d/init.d/rc 6

ca:12345:ctrlaltdel:/sbin/shutdown -t1 -a -r now

su:S016:once:/sbin/sulogin

1:2345:respawn:/sbin/agetty tty1 9600
2:2345:respawn:/sbin/agetty tty2 9600
3:2345:respawn:/sbin/agetty tty3 9600
4:2345:respawn:/sbin/agetty tty4 9600
5:2345:respawn:/sbin/agetty tty5 9600
6:2345:respawn:/sbin/agetty tty6 9600

# End /etc/inittab</literal>
EOF</userinput></screen>
</sect2>


<sect2 id="contents-sysvinit" role="content"><title>Contents of Sysvinit</title>

<segmentedlist>
<segtitle>Installed programs</segtitle>
<seglistitem><seg>halt, init, killall5, last, lastb (link to last), mesg, pidof (link to 
killall5), poweroff (link to halt), reboot (link to halt), runlevel, shutdown, sulogin, telinit 
(link to init), utmpdump, and wall</seg></seglistitem>
</segmentedlist>

<variablelist><bridgehead renderas="sect3">Short Descriptions</bridgehead>
<?dbfo list-presentation="list"?>
<?dbhtml list-presentation="table"?>

<varlistentry id="halt">
<term><command>halt</command></term>
<listitem>
<para>Normally invokes <command>shutdown</command> with the
<parameter>-h</parameter> option, except when already in run-level 0,
then it tells the kernel to halt the system; it notes in the
file <filename>/var/log/wtmp</filename> that the system is being
brought down</para>
<indexterm zone="ch-system-sysvinit halt"><primary sortas="b-halt">halt</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="init">
<term><command>init</command></term>
<listitem>
<para>The first process to be started when the kernel has initialized
the hardware which takes over the boot process and 
starts all the proceses it is instructed to</para>
<indexterm zone="ch-system-sysvinit init"><primary sortas="b-init">init</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="killall5">
<term><command>killall5</command></term>
<listitem>
<para>Sends a signal to all processes, except the processes in its own
session so it will not kill the shell running the script that called
it</para>
<indexterm zone="ch-system-sysvinit killall5"><primary sortas="b-killall5">killall5</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="last">
<term><command>last</command></term>
<listitem>
<para>Shows which users last logged in (and out),
searching back through the <filename>/var/log/wtmp</filename> file; it
also shows system boots, shutdowns, and run-level changes</para>
<indexterm zone="ch-system-sysvinit last"><primary sortas="b-last">last</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="lastb">
<term><command>lastb</command></term>
<listitem>
<para>Shows the failed login attempts, as logged in
<filename>/var/log/btmp</filename></para>
<indexterm zone="ch-system-sysvinit lastb"><primary sortas="b-lastb">lastb</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="mesg">
<term><command>mesg</command></term>
<listitem>
<para>Controls whether other users can send messages to the current
user's terminal</para>
<indexterm zone="ch-system-sysvinit mesg"><primary sortas="b-mesg">mesg</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="mountpoint">
<term><command>mountpoint</command></term>
<listitem>
<para>Checks if the directory is a mountpoint</para>
<indexterm zone="ch-system-sysvinit mountpoint"><primary sortas="b-mountpoint">mountpoint</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="pidof">
<term><command>pidof</command></term>
<listitem>
<para>Reports the PIDs of the given programs</para>
<indexterm zone="ch-system-sysvinit pidof"><primary sortas="b-pidof">pidof</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="poweroff">
<term><command>poweroff</command></term>
<listitem>
<para>Tells the kernel to halt the system and switch off the computer
(see <command>halt</command>)</para>
<indexterm zone="ch-system-sysvinit poweroff"><primary sortas="b-poweroff">poweroff</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="reboot">
<term><command>reboot</command></term>
<listitem>
<para>Tells the kernel to reboot the system (see
<command>halt</command>)</para>
<indexterm zone="ch-system-sysvinit reboot"><primary sortas="b-reboot">reboot</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="runlevel">
<term><command>runlevel</command></term>
<listitem>
<para>Reports the previous and the current run-level, as noted in the last run-level 
record in <filename>/var/run/utmp</filename></para>
<indexterm zone="ch-system-sysvinit runlevel"><primary sortas="b-runlevel">runlevel</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="shutdown">
<term><command>shutdown</command></term>
<listitem>
<para>Brings the system down in a secure way, signaling all processes
and notifying all logged-in users</para>
<indexterm zone="ch-system-sysvinit shutdown"><primary sortas="b-shutdown">shutdown</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="sulogin">
<term><command>sulogin</command></term>
<listitem>
<para>Allows <emphasis>root</emphasis> to log in; it is
normally invoked by <command>init</command> when the system goes into single user mode</para>
<indexterm zone="ch-system-sysvinit sulogin"><primary sortas="b-sulogin">sulogin</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="telinit">
<term><command>telinit</command></term>
<listitem>
<para>Tells <command>init</command> which run-level to change to</para>
<indexterm zone="ch-system-sysvinit telinit"><primary sortas="b-telinit">telinit</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="utmpdump">
<term><command>utmpdump</command></term>
<listitem>
<para>Displays the content of the given login file in a more
user-friendly format</para>
<indexterm zone="ch-system-sysvinit utmpdump"><primary sortas="b-utmpdump">utmpdump</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="wall">
<term><command>wall</command></term>
<listitem>
<para>Writes a message to all logged-in users</para>
<indexterm zone="ch-system-sysvinit wall"><primary sortas="b-wall">wall</primary></indexterm>
</listitem>
</varlistentry>
</variablelist>

</sect2>

</sect1>