7.3 Configuration files:

- tell people it's desirable to install both config.sample and config and
  provide a copy&pasteable lines for proper handling of it

Approved by:	keramida (mentor)

en_US.ISO8859-1/books/porters-handbook/book.sgml

@@ -5673,7 +5673,27 @@ lib/X11/oneko/sounds/cat.au
 
 	<para>Instead, install sample files with a suffix
 	  (<filename><replaceable>filename</replaceable>.sample</filename>
-	  will work well) and print out a <link
+	  will work well).  Copy the sample file as the real configuration
+	  file, if it does not exist.  On deinstall, delete the configuration
+	  file, but only if it was not modified by the user.  You need to
+	  handle this both in the port <filename>Makefile</filename>, and in
+	  the <filename>pkg-plist</filename> (for installation from
+	  the package).</para>
+
+	<para>Example of the <filename>Makefile</filename> part:</para>
+
+	<programlisting>post-install:
+	@if [ ! -f ${PREFIX}/etc/orbit.conf ]; then \
+		${CP} -p ${PREFIX}/etc/orbit.conf.sample ${PREFIX}/etc/orbit.conf ; \
+	fi</programlisting>
+
+	<para>Example of the <filename>pkg-plist</filename> part:</para>
+
+	<programlisting>@unexec if cmp -s %D/etc/orbit.conf.sample %D/etc/orbit.conf; then rm -f %D/etc/orbit.conf; fi
+etc/orbit.conf.sample
+@exec if [ ! -f %D/etc/orbit.conf ] ; then cp -p %D/%F %B/orbit.conf; fi</programlisting>
+
+	<para>Alternatively, print out a <link
 	    linkend="porting-message">message</link> pointing out that the
 	  user has to copy and edit the file before the software can be made
 	  to work.</para>