Added description to file -C

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@429 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter06/file-inst.xml

@@ -10,8 +10,27 @@ Install File by running the following commands:
 	<userinput>./configure --prefix=/usr 
 		--datadir=/usr/share/misc &amp;&amp;</userinput>
 	<userinput>make &amp;&amp;</userinput>
-	<userinput>make install &amp;&amp;</userinput>
-	<userinput>file -C</userinput>
+	<userinput>make install</userinput>
+
+</literallayout></blockquote>
+
+<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
+automagically 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>
+
+<blockquote><literallayout>
+
+        <userinput>file -C</userinput>
 
 </literallayout></blockquote>