lfs-book/chapter06/config-ldso.xml

<sect2>
<title>Configuring Dynamic Loader</title>

<para>
By default the dynamic loader searches a few default paths for dynamic
libraries, so there normally isn't a need for the
<filename>/etc/ld.so.conf</filename> file unless the system has extra
directories in which a user wants the system to search for paths. The
<filename class="directory">/usr/local/lib</filename> directory isn't
searched through for dynamic libraries by default, so we want to add
this path so when you install software you won't be surprised by them not
running for some reason.
</para>

<para>
Create a new file <filename>/etc/ld.so.conf</filename> by running the
following:
</para>

<para>
<screen>
<userinput>cat &gt; /etc/ld.so.conf &lt;&lt; "EOF"</userinput>
# Begin /etc/ld.so.conf

/lib
/usr/lib
/usr/local/lib

# End /etc/ld.so.conf
<userinput>EOF</userinput>
</screen>
</para>

<para>
Although it's not necessary to add the 
<filename class="directory">/lib</filename> and 
<filename class="directory">/usr/lib</filename> directories it doesn't 
hurt. This way it can be seen right away what's being searched and a you
don't have to remember the default search paths if you don't want to.
</para>

</sect2>