lfs-book/chapter06/file-inst.xml

<sect2>
<title>Installation of File</title>

<para>
Install File by running the following commands:
</para>

<para>
<screen>
<userinput>./configure --prefix=/usr --datadir=/usr/share/misc &amp;&amp;</userinput>
<userinput>make &amp;&amp;</userinput>
<userinput>make install</userinput>
</screen>
</para>

<para>
File uses magic numbers to determine a file type. These magic numbers come with
File in a plain text file.  File internally compiles this database each time it
is run. This is not the normal type of operation for File since compiling a
plain text file each time is not the fastest way to do it. File offers an
option "-C" to compile this magic number file. The reason this isn't done
automatically is that some people like to work on the magic numbers.  On the
other hand many people didn't get it that they should compile the magic
numbers, so the author of File added a warning when the plain text magic file
is used. As we usually won't work on the plain text magic file, we 
compile this file, because it's faster, fixes that annoying warning and is how
it was meant to be:
</para>

<para>
<screen>
<userinput>file -C</userinput>
</screen>
</para>

</sect2>