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/include/libbb.h b/include/libbb.h
index 135d911..ece03e7 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1219,6 +1219,7 @@
int find_applet_by_name(const char *name) FAST_FUNC;
void run_applet_no_and_exit(int a, const char *name, char **argv) NORETURN FAST_FUNC;
#endif
+void show_usage_if_dash_dash_help(int applet_no, char **argv) FAST_FUNC;
#if defined(__linux__)
void set_task_comm(const char *comm) FAST_FUNC;
#else