[PATCH iproute2-next 4/7] netshaper: put help to stdout and usage to stderr

[Stephen Hemminger <stephen@networkplumber.org>]

Similar change to other iproute2 commands.
Syntax error should print to stderr and exit with non-zero.
Help command should print to stdout and exit with zero status.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 netshaper/netshaper.c | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/netshaper/netshaper.c b/netshaper/netshaper.c
index 3b47d43d..85999dd5 100644
--- a/netshaper/netshaper.c
+++ b/netshaper/netshaper.c
@@ -26,9 +26,11 @@
 static struct rtnl_handle gen_rth = { .fd = -1 };
 static int genl_family = -1;
 
-static void usage(void)
+static void usage(bool help) __attribute__((noreturn));
+
+static void usage(bool help)
 {
-	fprintf(stderr,
+	fprintf(help ? stdout : stderr,
 		"Usage: netshaper [ OPTIONS ] { COMMAND | help }\n"
 		"OPTIONS := { -V[ersion] | -c[olor] | -help }\n"
 		"COMMAND := { set | get | delete | group } dev DEVNAME\n"
@@ -46,6 +48,8 @@ static void usage(void)
 		"       HANDLE_ID       := UINT (required for queue/node, optional for netdev)\n"
 		"       BW_MIN/BW_MAX   := UINT{ kbit | mbit | gbit }\n"
 		"       WEIGHT          := UINT\n");
+
+	exit(help ? EXIT_SUCCESS : EXIT_FAILURE);
 }
 
 static const char *net_shaper_scope_names[NET_SHAPER_SCOPE_MAX + 1] = {
@@ -243,7 +247,7 @@ static int do_cmd(int argc, char **argv, int cmd)
 
 			if (strcmp(*argv, "scope") != 0) {
 				fprintf(stderr, "What is \"%s\"\n", *argv);
-				usage();
+				usage(false);
 				return -1;
 			}
 			NEXT_ARG();
@@ -270,7 +274,7 @@ static int do_cmd(int argc, char **argv, int cmd)
 				NEXT_ARG();
 				if (strcmp(*argv, "id") != 0) {
 					fprintf(stderr, "What is \"%s\"\n", *argv);
-					usage();
+					usage(false);
 					return -1;
 				}
 				NEXT_ARG();
@@ -282,7 +286,7 @@ static int do_cmd(int argc, char **argv, int cmd)
 			}
 		} else {
 			fprintf(stderr, "What is \"%s\"\n", *argv);
-			usage();
+			usage(false);
 			return -1;
 		}
 		argc--;
@@ -363,7 +367,7 @@ static int parse_scope_id(const char *what, int *argcp, char ***argvp, int *scop
 		NEXT_ARG();
 		if (strcmp(*argv, "id") != 0) {
 			fprintf(stderr, "What is \"%s\"\n", *argv);
-			usage();
+			usage(false);
 			return -1;
 		}
 		NEXT_ARG();
@@ -517,7 +521,7 @@ static int do_group(int argc, char **argv)
 			continue;
 		} else {
 			fprintf(stderr, "What is \"%s\"\n", *argv);
-			usage();
+			usage(false);
 			goto free_leaves;
 		}
 		argc--;
@@ -609,8 +613,7 @@ int main(int argc, char **argv)
 			opt++;
 
 		if (strcmp(opt, "-help") == 0) {
-			usage();
-			exit(0);
+			usage(true);
 		} else if (strcmp(opt, "-Version") == 0 ||
 			   strcmp(opt, "-V") == 0) {
 			printf("netshaper utility, %s\n", version);
@@ -627,6 +630,9 @@ int main(int argc, char **argv)
 
 	check_enable_color(color, 0);
 
+	if (argc > 1 && strcmp(argv[1], "help") == 0)
+		usage(true);
+
 	if (genl_init_handle(&gen_rth, NET_SHAPER_FAMILY_NAME, &genl_family))
 		exit(1);
 
@@ -642,15 +648,10 @@ int main(int argc, char **argv)
 			return do_cmd(argc - 1, argv + 1, NET_SHAPER_CMD_GET);
 		if (strcmp(*argv, "group") == 0)
 			return do_group(argc - 1, argv + 1);
-		if (strcmp(*argv, "help") == 0) {
-			usage();
-			return 0;
-		}
 		fprintf(stderr,
 			"Command \"%s\" is unknown, try \"netshaper help\".\n",
 			*argv);
 		exit(-1);
 	}
-	usage();
-	exit(-1);
+	usage(false);
 }
-- 
2.53.0