Index: en_US.ISO8859-1/books/handbook/printing/chapter.xml
===================================================================
--- en_US.ISO8859-1/books/handbook/printing/chapter.xml
+++ en_US.ISO8859-1/books/handbook/printing/chapter.xml
@@ -775,11 +775,10 @@
 
 	<para>A filter that detects the type of input and
 	  automatically converts it to the correct format for the
-	  printer can be very convenient.  The first two characters of
-	  a &postscript; file are usually <literal>%!</literal>.  A
-	  filter can detect those two characters.  &postscript; files
-	  can be sent on to a &postscript; printer unchanged.  Text
-	  files can be converted to &postscript; with
+	  printer can be very convenient.  The &man.file.1;
+	  command can be leveraged to recognize &postscript; files.
+	  &postscript; files can be sent on to a &postscript; printer
+	  unchanged.  Text files can be converted to &postscript; with
 	  <application>Enscript</application> as shown earlier.
 	  Create <filename>/usr/local/libexec/psif</filename> with
 	  these contents:</para>
@@ -789,20 +788,22 @@
 #  psif - Print PostScript or plain text on a PostScript printer
 #
 IFS="" read -r first_line
-first_two_chars=`expr "$first_line" : '\(..\)'`
 
-case "$first_two_chars" in
-%!)
-    # %! : PostScript job, print it.
+# Pass $first_line to file(1) and extract the mime type it found
+mime=`echo "$first_line" | file -bi - | cut -f 1 -d ";"`
+
+if [ "$mime" = "application/postscript" ]; then
+    # PostScript job, print it.
     echo "$first_line" &amp;&amp; cat &amp;&amp; exit 0
     exit 2
-    ;;
-*)
-    # otherwise, format with enscript
+elif [ "${mime%%/*}" = "text" ]; then
+    # Text file, format with enscript
     ( echo "$first_line"; cat ) | /usr/local/bin/enscript -o - &amp;&amp; exit 0
     exit 2
-    ;;
-esac</programlisting>
+fi
+
+# Unsupported MIME type, exit with error state
+exit 2</programlisting>
 
 	<para>Set the permissions and make it executable:</para>