lfs-book/appendixa/ldso-desc.sgml

<sect2><title>Contents</title>

<para>
From the Ld.so package we're using the ldconfig and ldd programs.
</para>

</sect2>

<sect2><title>Description</title>

<sect3><title>ldconfig</title>

<para>
ldconfig creates the necessary links and cache (for use by the  run-time 
linker, ld.so) to the most recent shared libraries found in the directories 
specified on the command line, in the file /etc/ld.so.conf, and in the trusted
directories (/usr/lib and /lib). ldconfig checks the header and file names 
of the libraries it encounters when determining which versions should  
have their links updated.
</para>

</sect3>

<sect3><title>ldd</title>

<para>
ldd prints the shared libraries required by each program or shared library 
specified on the command line.
</para>

</sect3>

</sect2>