Implementation of dependency checking 3

Add an XSL stylesheet for listing packages in LFS. Those are
not listed anywhere else, but they are considered dependencies of
everything, so should never be erased.

BLFS/gen_pkg_book.sh

@@ -28,6 +28,7 @@ declare BookXml="${TOPDIR}/book.xml"
 declare MakeBook="${TOPDIR}/xsl/make_book.xsl"
 declare GetVersion="${TOPDIR}/xsl/get_version.xsl"
 declare MakeScripts="${TOPDIR}/xsl/scripts.xsl"
+declare ListLFS="${TOPDIR}/xsl/list_lfs.xsl"
 declare BookHtml="${TOPDIR}/book-html"
 declare BLFS_XML="${TOPDIR}/blfs-xml"
 declare -a TARGET

BLFS/xsl/list_lfs.xsl

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="ISO-8859-1"?>
+
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+                version="1.0">
+
+  <xsl:output method="text"/>
+
+  <xsl:template match="/">
+    <xsl:text>bootscripts </xsl:text>
+    <xsl:text>lfs-bootscripts </xsl:text>
+    <xsl:text>kernel </xsl:text>
+    <xsl:apply-templates select=".//chapter[@id='chapter-building-system']/sect1/sect1info/productname"/>
+  </xsl:template>
+
+  <xsl:template match="productname">
+    <xsl:copy-of select="text()"/>
+    <xsl:text> </xsl:text>
+  </xsl:template>
+
+</xsl:stylesheet>