Add ValidUUID() predicate.

db/emutil.pm.in

 #!/usr/bin/perl -w
 #
-# Copyright (c) 2000-2016 University of Utah and the Flux Group.
+# Copyright (c) 2000-2017 University of Utah and the Flux Group.
 # 
 # {{{EMULAB-LICENSE
 # 
@@ -34,7 +34,7 @@ use vars qw(@ISA @EXPORT);
 	     TBGetUniqueIndex ParRun VersionInfo UpdateVersionInfo
 	     SpanningTree GenFakeMac BackTraceOnWarning PassWordHash
              SSHwithTimeout TBDateStringGMT TBDateStringLocal runBusyLoop
-	     MapEventType MapEventObjectType MapEventTriggerType
+	     MapEventType MapEventObjectType MapEventTriggerType ValidUUID
 );
 
 use emdb;
@@ -992,5 +992,14 @@ sub MapEventTriggerType($)
     return $idx;
 }
 
+sub ValidUUID($)
+{
+    my ($uuid) = @_;
+    if ($uuid =~ /^\w+\-\w+\-\w+\-\w+\-\w+$/) {
+	return 1;
+    }
+    return 0;
+}
+
 # _Always_ make sure that this 1 is at the end of the file...
 1;