3484 enhance and document tail follow support
Reviewed by: Joshua M. Clulow <jmc@joyent.com>

@@ -22,15 +22,17 @@
 /*
  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
+/*
+ * Copyright (c) 2013, Joyent, Inc. All rights reserved.
+ */
+
 #ifndef _SYS_PORT_H
 #define _SYS_PORT_H
 
-#pragma ident   "%Z%%M% %I%     %E% SMI"
-
 #ifdef  __cplusplus
 extern "C" {
 #endif
 
 #include <sys/types.h>

@@ -104,10 +106,11 @@
  * User watchable file events
  */
 #define FILE_ACCESS             0x00000001
 #define FILE_MODIFIED           0x00000002
 #define FILE_ATTRIB             0x00000004
+#define FILE_TRUNC              0x00100000
 #define FILE_NOFOLLOW           0x10000000
 
 /*
  * exception file events
  */