ADDED   xvfs-create-random
Index: xvfs-create-random
==================================================================
--- xvfs-create-random
+++ xvfs-create-random
@@ -0,0 +1,17 @@
+#! /usr/bin/env tclsh
+
+set sourceDirectory [file dirname [file normalize [info script]]]
+lappend auto_path [file join $sourceDirectory lib]
+package require xvfs
+
+proc ::xvfs::callback::setOutputFileName {file workingDirectory inputFile outputDirectory outputFile} {
+	if {$outputFile eq ""} {
+		return $outputFile
+	}
+
+	set outputFile [expr rand()]
+
+	return $outputFile
+}
+
+::xvfs::run --directory [pwd]/example --name random