Allow appending to default props for zfs and zpool list.

cmd/zfs/zfs_main.c

@@ -3863,6 +3863,7 @@ zfs_do_list(int argc, char **argv)
 	zfs_sort_column_t *sortcol = NULL;
 	int flags = ZFS_ITER_PROP_LISTSNAPS | ZFS_ITER_ARGS_CAN_BE_PATHS;
 	nvlist_t *data = NULL;
+	char full_fields[1024];
 
 	struct option long_options[] = {
 		{"json", no_argument, NULL, 'j'},
@@ -3875,7 +3876,23 @@ zfs_do_list(int argc, char **argv)
 	    NULL)) != -1) {
 		switch (c) {
 		case 'o':
-			fields = optarg;
+			if (optarg[0] == '+') {
+				/* +2 for the , and the null terminator */
+				if (strlen(fields) + strlen(optarg + 1) + 2 <=
+				    1024) {
+					(void) snprintf(full_fields,
+					    sizeof (full_fields), "%s,%s",
+					    fields, optarg + 1);
+				} else {
+					(void) fprintf(stderr, gettext(
+					    "argument too long for '-o'"
+					    " option.\n"));
+					usage(B_FALSE);
+				}
+				fields = full_fields;
+			} else {
+				fields = optarg;
+			}
 			break;
 		case 'p':
 			cb.cb_literal = B_TRUE;

cmd/zpool/zpool_main.c

@@ -7400,6 +7400,7 @@ zpool_do_list(int argc, char **argv)
 	boolean_t first = B_TRUE;
 	nvlist_t *data = NULL;
 	current_prop_type = ZFS_TYPE_POOL;
+	char full_props[1024];
 
 	struct option long_options[] = {
 		{"json", no_argument, NULL, 'j'},
@@ -7423,7 +7424,23 @@ zpool_do_list(int argc, char **argv)
 			cb.cb_name_flags |= VDEV_NAME_FOLLOW_LINKS;
 			break;
 		case 'o':
-			props = optarg;
+			if (optarg[0] == '+') {
+				/* +2 for the , and the null terminator */
+				if (strlen(props) + strlen(optarg + 1) + 2 <=
+				    1024) {
+					(void) snprintf(full_props,
+					    sizeof (full_props), "%s,%s",
+					    props, optarg + 1);
+				} else {
+					(void) fprintf(stderr, gettext(
+					    "argument too long for '-o'"
+					    " option.\n"));
+					usage(B_FALSE);
+				}
+				props = full_props;
+			} else {
+				props = optarg;
+			}
 			break;
 		case 'P':
 			cb.cb_name_flags |= VDEV_NAME_PATH;

man/man8/zfs-list.8

@@ -107,6 +107,13 @@ This is a shortcut for specifying
 .Sy usedds , Ns Sy usedrefreserv , Ns Sy usedchild
 .Fl t Sy filesystem , Ns Sy volume .
 .El
+.Pp
+The default list of properties can be extended by using
+.Sy +property
+instead of
+.Sy property .
+For example,
+.Sy zfs list -o +guid .
 .It Fl p
 Display numbers in parsable
 .Pq exact

man/man8/zpool-list.8

@@ -84,6 +84,13 @@ manual page for a list of valid properties.
 The default list is
 .Sy name , size , allocated , free , checkpoint, expandsize , fragmentation ,
 .Sy capacity , dedupratio , health , altroot .
+.Pp
+The default list of properties can be extended by using
+.Sy +property
+instead of
+.Sy property .
+For example,
+.Sy zpool list -o +guid .
 .It Fl L
 Display real paths for vdevs resolving all symbolic links.
 This can be used to look up the current block device name regardless of the