*
* Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
+//config:config USLEEP
+//config: bool "usleep (1.1 kb)"
+//config: default y
+//config: help
+//config: usleep is used to pause for a specified number of microseconds.
+
+//applet:IF_USLEEP(APPLET_NOFORK(usleep, usleep, BB_DIR_BIN, BB_SUID_DROP, usleep))
+
+//kbuild:lib-$(CONFIG_USLEEP) += usleep.o
/* BB_AUDIT SUSv3 N/A -- Apparently a busybox extension. */
+//usage:#define usleep_trivial_usage
+//usage: "N"
+//usage:#define usleep_full_usage "\n\n"
+//usage: "Pause for N microseconds"
+//usage:
+//usage:#define usleep_example_usage
+//usage: "$ usleep 1000000\n"
+//usage: "[pauses for 1 second]\n"
+
#include "libbb.h"
/* This is a NOFORK applet. Be very careful! */
-int usleep_main(int argc, char **argv);
-int usleep_main(int argc, char **argv)
+int usleep_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int usleep_main(int argc UNUSED_PARAM, char **argv)
{
- if (argc != 2) {
+ if (!argv[1]) {
bb_show_usage();
}
- if (usleep(xatou(argv[1]))) {
- bb_perror_nomsg_and_die();
- }
+ /* Safe wrt NOFORK? (noforks are not allowed to run for
+ * a long time). Try "usleep 99999999" + ^C + "echo $?"
+ * in hush with FEATURE_SH_NOFORK=y.
+ * At least on uclibc, usleep() thanslates to nanosleep()
+ * which returns early on any signal (even caught one),
+ * and uclibc does not loop back on EINTR.
+ */
+ usleep(xatou(argv[1]));
return EXIT_SUCCESS;
}