blob: 51a015c440625fd17e6cd1f3293fea35e7d850ba [file] [log] [blame]
/* vi: set sw=4 ts=4: */
* usleep implementation for busybox
* Copyright (C) 2003 Manuel Novoa III <>
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
//config:config USLEEP
//config: bool "usleep (1.3 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-$(CONFIG_USLEEP) += usleep.o
/* BB_AUDIT SUSv3 N/A -- Apparently a busybox extension. */
//usage:#define usleep_trivial_usage
//usage: "N"
//usage:#define usleep_full_usage "\n\n"
//usage: "Pause for N microseconds"
//usage:#define usleep_example_usage
//usage: "$ 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) MAIN_EXTERNALLY_VISIBLE;
int usleep_main(int argc UNUSED_PARAM, char **argv)
if (!argv[1]) {
/* 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.