[PATCH net-next 02/12] tools: bpftool: add option parsing to bpftool, --help and --version

[Jakub Kicinski]

From: Quentin Monnet <quentin.mon...@netronome.com>

Add an option parsing facility to bpftool, in prevision of future
options for demanding JSON output. Currently, two options are added:
--help and --version, that act the same as the respective commands
`help` and `version`.

Signed-off-by: Quentin Monnet <quentin.mon...@netronome.com>
---
 tools/bpf/bpftool/Documentation/bpftool-map.rst  |  8 +++++++
 tools/bpf/bpftool/Documentation/bpftool-prog.rst |  8 +++++++
 tools/bpf/bpftool/Documentation/bpftool.rst      |  8 +++++++
 tools/bpf/bpftool/main.c                         | 27 +++++++++++++++++++++++-
 4 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst 
b/tools/bpf/bpftool/Documentation/bpftool-map.rst
index ff63e89e4b6c..5210c4fab356 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-map.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst
@@ -68,6 +68,14 @@ DESCRIPTION
        **bpftool map help**
                  Print short help message.
 
+OPTIONS
+=======
+       -h, --help
+                 Print short generic help message (similar to **bpftool 
help**).
+
+       -v, --version
+                 Print version number (similar to **bpftool version**).
+
 EXAMPLES
 ========
 **# bpftool map show**
diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst 
b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
index 69b3770370c8..6620a81d9dc9 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -50,6 +50,14 @@ DESCRIPTION
        **bpftool prog help**
                  Print short help message.
 
+OPTIONS
+=======
+       -h, --help
+                 Print short generic help message (similar to **bpftool 
help**).
+
+       -v, --version
+                 Print version number (similar to **bpftool version**).
+
 EXAMPLES
 ========
 **# bpftool prog show**
diff --git a/tools/bpf/bpftool/Documentation/bpftool.rst 
b/tools/bpf/bpftool/Documentation/bpftool.rst
index 45ad8baf1915..9c04cd6677bd 100644
--- a/tools/bpf/bpftool/Documentation/bpftool.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool.rst
@@ -31,6 +31,14 @@ DESCRIPTION
        Note that format of the output of all tools is not guaranteed to be
        stable and should not be depended upon.
 
+OPTIONS
+=======
+       -h, --help
+                 Print short help message (similar to **bpftool help**).
+
+       -v, --version
+                 Print version number (similar to **bpftool version**).
+
 SEE ALSO
 ========
        **bpftool-map**\ (8), **bpftool-prog**\ (8)
diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c
index 814d19e1b53f..613e3c75f78a 100644
--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -36,6 +36,7 @@
 #include <bfd.h>
 #include <ctype.h>
 #include <errno.h>
+#include <getopt.h>
 #include <linux/bpf.h>
 #include <linux/version.h>
 #include <stdio.h>
@@ -215,8 +216,32 @@ static int do_batch(int argc, char **argv)
 
 int main(int argc, char **argv)
 {
+       static const struct option options[] = {
+               { "help",       no_argument,    NULL,   'h' },
+               { "version",    no_argument,    NULL,   'V' },
+               { 0 }
+       };
+       int opt;
+
+       last_do_help = do_help;
        bin_name = argv[0];
-       NEXT_ARG();
+
+       while ((opt = getopt_long(argc, argv, "Vh",
+                                 options, NULL)) >= 0) {
+               switch (opt) {
+               case 'V':
+                       return do_version(argc, argv);
+               case 'h':
+                       return do_help(argc, argv);
+               default:
+                       usage();
+               }
+       }
+
+       argc -= optind;
+       argv += optind;
+       if (argc < 0)
+               usage();
 
        bfd_init();
 
-- 
2.14.1