libbb: fix '--help' handling in FEATURE_SH_NOFORK=y
Most BusyBox applets respond to the '--help' option by printing
a usage message. This is normally handled by busybox_main() so
applet main routines don't have support for '--help'.
In standalone shell mode with FEATURE_SH_NOFORK enabled nofork
applets are invoked directly, bypassing busybox_main(). This
results in inconsistent handling of '--help':
- applets which call getopt() report "unrecognized option '--help'"
and print help anyway;
- realpath says "--help: No such file or directory" and doesn't
print help;
- usleep says "invalid number '--help'" and doesn't print help.
Avoid inconsistency by checking for '--help' in run_nofork_applet().
Bug found by Ron Yorston.
function old new delta
show_usage_if_dash_dash_help - 70 +70
run_nofork_applet 347 362 +15
run_applet_no_and_exit 432 365 -67
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/1 up/down: 85/-67) Total: 18 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index 5422112..67c540a 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -905,16 +905,8 @@
# endif
# if NUM_APPLETS > 0
-void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **argv)
+void FAST_FUNC show_usage_if_dash_dash_help(int applet_no, char **argv)
{
- int argc = string_array_len(argv);
-
- /*
- * We do not use argv[0]: do not want to repeat massaging of
- * "-/sbin/halt" -> "halt", for example.
- */
- applet_name = name;
-
/* Special case. POSIX says "test --help"
* should be no different from e.g. "test --foo".
* Thus for "test", we skip --help check.
@@ -931,15 +923,32 @@
&& applet_no != APPLET_NO_false
# endif
) {
- if (argc == 2 && strcmp(argv[1], "--help") == 0) {
+ if (argv[1] && !argv[2] && strcmp(argv[1], "--help") == 0) {
/* Make "foo --help" exit with 0: */
xfunc_error_retval = 0;
bb_show_usage();
}
}
+}
+
+void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **argv)
+{
+ int argc;
+
+ /*
+ * We do not use argv[0]: do not want to repeat massaging of
+ * "-/sbin/halt" -> "halt", for example.
+ */
+ applet_name = name;
+
+ show_usage_if_dash_dash_help(applet_no, argv);
+
if (ENABLE_FEATURE_SUID)
check_suid(applet_no);
+
+ argc = string_array_len(argv);
xfunc_error_retval = applet_main[applet_no](argc, argv);
+
/* Note: applet_main() may also not return (die on a xfunc or such) */
xfunc_die();
}