enosys: add common arguments

Signed-off-by: Thomas Weißschuh <thomas@t-8ch.de>

diff --git a/misc-utils/enosys.c b/misc-utils/enosys.c
index 5a337fd81356f09c4c9950818cd8c6696e220997..793b646463ed3789c7548bb1df60e50629c38977 100644 (file)
--- a/misc-utils/enosys.c
+++ b/misc-utils/enosys.c
@@ -73,6 +73,24 @@ static const struct syscall syscalls[] = {
        { "fallocate", __NR_fallocate },
 };
 
+static void __attribute__((__noreturn__)) usage(void)
+{
+       FILE *out = stdout;
+
+       fputs(USAGE_HEADER, out);
+       fprintf(out, _(" %s [options] -- <command>\n"), program_invocation_short_name);
+
+       fputs(USAGE_OPTIONS, out);
+       fputs(_(" -s, --syscall           syscall to block\n"), out);
+
+       fputs(USAGE_SEPARATOR, out);
+       fprintf(out, USAGE_HELP_OPTIONS(25));
+
+       fprintf(out, USAGE_MAN_TAIL("enosys(1)"));
+
+       exit(EXIT_SUCCESS);
+}
+
 int main(int argc, char **argv)
 {
        int c;
@@ -80,12 +98,14 @@ int main(int argc, char **argv)
        bool found;
        static const struct option longopts[] = {
                { "syscall", required_argument, NULL, 's' },
+               { "version", no_argument,       NULL, 'V' },
+               { "help",    no_argument,       NULL, 'h' },
                { 0 }
        };
 
        bool blocked_syscalls[ARRAY_SIZE(syscalls)] = {};
 
-       while ((c = getopt_long (argc, argv, "s:", longopts, NULL)) != -1) {
+       while ((c = getopt_long (argc, argv, "Vhs:", longopts, NULL)) != -1) {
                switch (c) {
                case 's':
                        found = 0;
@@ -99,13 +119,17 @@ int main(int argc, char **argv)
                        if (!found)
                                errx(EXIT_FAILURE, "Unknown syscall '%s'", optarg);
                        break;
+               case 'V':
+                       print_version(EXIT_SUCCESS);
+               case 'h':
+                       usage();
                default:
-                       errx(EXIT_FAILURE, "Unknown option");
+                       errtryhelp(EXIT_FAILURE);
                }
        }
 
        if (optind >= argc)
-               errx(EXIT_FAILURE, "No executable specified");
+               errtryhelp(EXIT_FAILURE);
 
 #define N_FILTERS (ARRAY_SIZE(syscalls) + 3)