Illumos #2803: zfs get guid pretty-prints the output

Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Richard Elling <richard.elling@gmail.com>
Reviewed by: Alexander Eremin <alexander.eremin@nexenta.com>
Approved by: Dan McDonald <danmcd@nexenta.com>

References:
  https://www.illumos.org/issues/2803

Ported by: Martin Matuska <martin@matuska.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

Author: gdamore

lib/libzfs/libzfs_dataset.c

@@ -23,6 +23,7 @@
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2010 Nexenta Systems, Inc. All rights reserved.
  * Copyright (c) 2012 by Delphix. All rights reserved.
+ * Copyright (c) 2012 DEY Storage Systems, Inc.  All rights reserved.
  * Copyright (c) 2012 Pawel Jakub Dawidek <pawel@dawidek.net>.
  */
 
@@ -2313,6 +2314,17 @@ zfs_prop_get(zfs_handle_t *zhp, zfs_prop_t prop, char *propbuf, size_t proplen,
 		}
 		break;
 
+	case ZFS_PROP_GUID:
+		/*
+		 * GUIDs are stored as numbers, but they are identifiers.
+		 * We don't want them to be pretty printed, because pretty
+		 * printing mangles the ID into a truncated and useless value.
+		 */
+		if (get_numeric_property(zhp, prop, src, &source, &val) != 0)
+			return (-1);
+		(void) snprintf(propbuf, proplen, "%llu", (u_longlong_t)val);
+		break;
+
 	default:
 		switch (zfs_prop_get_type(prop)) {
 		case PROP_TYPE_NUMBER: