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;.patch</userinput></screen></para>

<para>Now prepare Zlib for compilation:</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>Compile the package:</para>

<para><screen><userinput>make</userinput></screen></para>

<para>Install the shared libraries:</para>

<para><screen><userinput>make install</userinput></screen></para>

<para>Now also build and install the non-shared libraries:</para>
<para><screen><userinput>make clean
./configure --prefix=/usr
make
make test
make 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>