2 files changed, 15 insertions, 2 deletions

diff --git a/coreutils/sleep.c b/coreutils/sleep.c
index 442841210..667db558d 100644
--- a/coreutils/sleep.c
+++ b/coreutils/sleep.c
@@ -65,15 +65,28 @@ int sleep_main(int argc UNUSED_PARAM, char **argv)
 {
         duration_t duration;
 
+        /* Note: sleep_main may be directly called from ash as a builtin.
+         * This brings some complications:
+         * + we can't use xfunc here
+         * + we can't use bb_show_usage
+         * + applet_name can be the name of the shell
+         */
         ++argv;
-        if (!*argv)
+        if (!*argv) {
+                /* Without this, bare "sleep" in ash shows _ash_ --help */
+                if (ENABLE_ASH_SLEEP && applet_name[0] != 's') {
+                        bb_simple_error_msg("sleep: missing operand");
+                        return EXIT_FAILURE;
+                }
                 bb_show_usage();
+        }
 
         /* GNU sleep accepts "inf", "INF", "infinity" and "INFINITY" */
         if (strncasecmp(argv[0], "inf", 3) == 0)
                 for (;;)
                         sleep(INT_MAX);
 
+//FIXME: in ash, "sleep 123qwerty" as a builtin aborts the shell
 #if ENABLE_FEATURE_FANCY_SLEEP
         duration = 0;
         do {
diff --git a/procps/kill.c b/procps/kill.c
index 8f10e21ab..208efebde 100644
--- a/procps/kill.c
+++ b/procps/kill.c
@@ -85,8 +85,8 @@
  * This brings some complications:
  *
  * + we can't use xfunc here
- * + we can't use applet_name
  * + we can't use bb_show_usage
+ * + applet_name can be the name of the shell
  * (doesn't apply for killall[5], still should be careful b/c NOFORK)
  *
  * kill %n gets translated into kill ' -<process group>' by shell (note space!)