[PATCH iproute2] ip: return correct status from help command

[PATCH iproute2] ip: return correct status from help command

[Rose Wright]

Currently, "ip help" or "ip -help" always returns an error code because usage() is used as a fall through on "ip" and defaults to stderr with -1.

This is a minor bug that breaks "ip help | grep" and other scripts that rely on standard exit codes. The fix is to pass the status code as a parameter into usage() and change stderr to stdout when needed.

Signed-off-by: Rose Wright <rosesophiewright@gmail.com>
---
 ip/ip.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/ip/ip.c b/ip/ip.c
index e4b71bde..ee4595e8 100644
--- a/ip/ip.c
+++ b/ip/ip.c
@@ -52,11 +52,12 @@ const char *get_ip_lib_dir(void)
 	return lib_dir;
 }
 
-static void usage(void) __attribute__((noreturn));
+static void usage(int status) __attribute__((noreturn));
 
-static void usage(void)
+static void usage(int status)
 {
-	fprintf(stderr,
+	FILE *out = status == 0 ? stdout : stderr;
+	fprintf(out,
 		"Usage: ip [ OPTIONS ] OBJECT { COMMAND | help }\n"
 		"       ip [ -force ] -batch filename\n"
 		"where  OBJECT := { address | addrlabel | fou | help | ila | ioam | l2tp | link |\n"
@@ -72,12 +73,12 @@ static void usage(void)
 		"                    -o[neline] | -t[imestamp] | -ts[hort] | -b[atch] [filename] |\n"
 		"                    -rc[vbuf] [size] | -n[etns] name | -N[umeric] | -a[ll] |\n"
 		"                    -c[olor]}\n");
-	exit(-1);
+	exit(status);
 }
 
 static int do_help(int argc, char **argv)
 {
-	usage();
+	usage(0);
 	return 0;
 }
 
@@ -279,7 +280,7 @@ int main(int argc, char **argv)
 			rcvbuf = size;
 		} else if (matches_color(opt, &color)) {
 		} else if (matches(opt, "-help") == 0) {
-			usage();
+			usage(0);
 		} else if (matches(opt, "-netns") == 0) {
 			NEXT_ARG();
 			if (netns_switch(argv[1]))
@@ -321,5 +322,5 @@ int main(int argc, char **argv)
 		return do_cmd(argv[1], argc-1, argv+1, true);
 
 	rtnl_close(&rth);
-	usage();
+	usage(-1);
 }
-- 
2.54.0

Re: [PATCH iproute2] ip: return correct status from help command

[Stephen Hemminger]

On Sun, 21 Jun 2026 18:03:11 +0000
Rose Wright <rosesophiewright@gmail.com> wrote:

> Currently, "ip help" or "ip -help" always returns an error code because usage() is used as a fall through on "ip" and defaults to stderr with -1.
> 
> This is a minor bug that breaks "ip help | grep" and other scripts that rely on standard exit codes. The fix is to pass the status code as a parameter into usage() and change stderr to stdout when needed.
> 
> Signed-off-by: Rose Wright <rosesophiewright@gmail.com>
> ---

This is the closest of the three submissions, but there are way more commands in iproute2
than just ip. Need to address all the commands. Looks like perfect trivial job for AI
coding tools. I am looking into it now.