lfs-book/appendixa/m4-desc.xml

<sect2><title>Contents of m4-&m4-contversion;</title>

<sect3><title>Program Files</title>
<para>m4</para></sect3>

<sect3><title>Descriptions</title>

<sect4><title>m4</title>
<para>M4 is a macro processor. It copies input to output expanding macros as it 
goes. Macros are either built-in or user-defined and can take any number
of arguments. Besides just doing macro expansion m4 has built-in functions 
for including named files, running UNIX commands, doing integer arithmetic, 
manipulating text in various ways, recursion, etc. M4 can be used either 
as a front-end to a compiler or as a macro processor in its own
right.</para></sect4>

</sect3>

</sect2>