lfs-book/chapter06/zlib-inst.xml

<sect2><title>&nbsp;</title><para>&nbsp;</para></sect2>

<sect2>
<title>Installation of Zlib</title>

<para>Zlib has a potential buffer overflow in its gzprintf() function,
that, though difficult to take advantage of, should be taken care of. Do
so by applying this patch:</para>

<para><screen><userinput>patch -Np1 -i ../zlib-&zlib-patch-version;</userinput></screen></para>

<para>Prepare Zlib to be compiled:</para>

<para><screen><userinput>CFLAGS="$CFLAGS -fPIC" \
&nbsp;&nbsp;&nbsp;&nbsp;./configure --prefix=/usr --shared</userinput></screen></para>

<para>The <emphasis>-fPIC</emphasis> flag helps to assure
quality in the dynamic zlib library.</para>

<para>Some packages expect a static zlib library to be present
on the system. To satisfy those programs, compile both the
shared and static libraries:</para>

<para><screen><userinput>make LIBS="libz.so.1.1.4 libz.a"</userinput></screen></para>

<para>Install the libraries:</para>

<para><screen><userinput>make LIBS="libz.so.1.1.4 libz.a" install</userinput></screen></para>

<para>The shared zlib library should be installed in the
<filename>/lib</filename> directory. That way, in the event
that you must boot without the <filename>/usr</filename>
directory, vital system programs will still have access to
the library:</para>

<para><screen><userinput>mv /usr/lib/libz.so.* /lib</userinput></screen></para>

<para>The <filename>/usr/lib/libz.so</filename> symlink is
linked to a file which no longer exists, because we moved
it. Create a symbolic link to the new location of the
library:</para>

<para><screen><userinput>ln -sf ../../lib/libz.so.1 /usr/lib/libz.so</userinput></screen></para>

<para>Zlib does not install its manual page. Issue the
following command to install this documentation:</para>

<para><screen><userinput>cp zlib.3 /usr/share/man/man3</userinput></screen></para>

</sect2>