iplink: shortify printing the usage of link type

Allow to print link type usage by: ip link help bridge_slave

Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>

diff --git a/ip/iplink_bridge_slave.c b/ip/iplink_bridge_slave.c
index a2851855e2ee81d877a3125a545a4e6c94fbf616..4593872ecd84d36ae056a2fe2915151cdcc99f5f 100644 (file)
--- a/ip/iplink_bridge_slave.c
+++ b/ip/iplink_bridge_slave.c
@@ -19,9 +19,9 @@
 #include "utils.h"
 #include "ip_common.h"
 
-static void explain(void)
+static void print_explain(FILE *f)
 {
-       fprintf(stderr,
+       fprintf(f,
                "Usage: ... bridge_slave [ state STATE ] [ priority PRIO ] [cost COST ]\n"
                "                        [ guard {on | off} ]\n"
                "                        [ hairpin {on | off} ] \n"
@@ -32,6 +32,11 @@ static void explain(void)
        );
 }
 
+static void explain(void)
+{
+       print_explain(stderr);
+}
+
 static const char *port_states[] = {
        [BR_STATE_DISABLED] = "disabled",
        [BR_STATE_LISTENING] = "listening",
@@ -172,10 +177,17 @@ static int bridge_slave_parse_opt(struct link_util *lu, int argc, char **argv,
        return 0;
 }
 
+static void bridge_slave_print_help(struct link_util *lu, int argc, char **argv,
+               FILE *f)
+{
+       print_explain(f);
+}
+
 struct link_util bridge_slave_link_util = {
        .id             = "bridge",
        .maxattr        = IFLA_BRPORT_MAX,
        .print_opt      = bridge_slave_print_opt,
        .parse_opt      = bridge_slave_parse_opt,
+       .print_help     = bridge_slave_print_help,
        .slave          = true,
 };