lfs/chapter06/ed-inst.xml

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

<sect2>
<title>Installation of Ed</title>

<note><para>Ed isn't something which many people use. It's installed here
because it can be used by the patch program if you encounter an ed-based patch
file. This happens rarely because diff-based patches are preferred these
days.</para></note>

<para>This package requires its patch to be applied before you can
install it. This patch fixes a symlink vulnerability in
<userinput>ed</userinput>. The <userinput>ed</userinput> executable
creates files in <filename class="directory">/tmp</filename> with
predictable names. By using various symlink attacks, it is possible
to have ed write to files it should not, change the permissions of
files, etc.</para>

<para>Apply the patch:</para>

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

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

<para><screen><userinput>./configure --prefix=/usr</userinput></screen></para>

<para>Continue with compiling the package:</para>

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

<para>And finish off installing the package:</para>

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

<para>We need to move the Ed binaries to the <filename
class="directory">/bin</filename> directory so they may be used in
the event that the <filename class="directory">/usr</filename>
partition is unavailable.</para>

<para><screen><userinput>mv /usr/bin/{ed,red} /bin</userinput></screen></para>

</sect2>