tools, bpftool: Clean subcommand help messages

This is a clean-up for the formatting of the do_help functions for
bpftool's subcommands. The following fixes are included:

- Do not use argv[-2] for "iter" help message, as the help is shown by
  default if no "iter" action is selected, resulting in messages looking
  like "./bpftool bpftool pin...".

- Do not print unused HELP_SPEC_PROGRAM in help message for "bpftool
  link".

- Andrii used argument indexing to avoid having multiple occurrences of
  bin_name and argv[-2] in the fprintf() for the help message, for
  "bpftool gen" and "bpftool link". Let's reuse this for all other help
  functions. We can remove up to thirty arguments for the "bpftool map"
  help message.

- Harmonise all functions, e.g. use ending quotes-comma on a separate
  line.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200523010751.23465-1-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 6 insertions, 6 deletions

diff --git a/tools/bpf/bpftool/net.c b/tools/bpf/bpftool/net.c
index c5e3895b7c8b..56c3a2bae3ef 100644
--- a/tools/bpf/bpftool/net.c
+++ b/tools/bpf/bpftool/net.c
@@ -458,10 +458,10 @@ static int do_help(int argc, char **argv)
 	}
 
 	fprintf(stderr,
-		"Usage: %s %s { show | list } [dev <devname>]\n"
-		"       %s %s attach ATTACH_TYPE PROG dev <devname> [ overwrite ]\n"
-		"       %s %s detach ATTACH_TYPE dev <devname>\n"
-		"       %s %s help\n"
+		"Usage: %1$s %2$s { show | list } [dev <devname>]\n"
+		"       %1$s %2$s attach ATTACH_TYPE PROG dev <devname> [ overwrite ]\n"
+		"       %1$s %2$s detach ATTACH_TYPE dev <devname>\n"
+		"       %1$s %2$s help\n"
 		"\n"
 		"       " HELP_SPEC_PROGRAM "\n"
 		"       ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload }\n"
@@ -470,8 +470,8 @@ static int do_help(int argc, char **argv)
 		"      For progs attached to cgroups, use \"bpftool cgroup\"\n"
 		"      to dump program attachments. For program types\n"
 		"      sk_{filter,skb,msg,reuseport} and lwt/seg6, please\n"
-		"      consult iproute2.\n",
-		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
+		"      consult iproute2.\n"
+		"",
 		bin_name, argv[-2]);
 
 	return 0;