Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

usleep(1) [centos man page]

USLEEP(1)						      General Commands Manual							 USLEEP(1)

usleep - sleep some number of microseconds SYNOPSIS
usleep [number] DESCRIPTION
usleep sleeps some number of microseconds. The default is 1. OPTIONS
--usage Show short usage message. --help, -? Print help information. -v, --version Print version information. BUGS
Probably not accurate on many machines down to the microsecond. Count on precision only to -4 or maybe -5. AUTHOR
Donald Barnes <> Erik Troan <> Red Hat, Inc USLEEP(1)

Check Out this Related Man Page

USLEEP(3)						     Library Functions Manual							 USLEEP(3)

usleep - suspend execution for interval SYNOPSIS
usleep(useconds) unsigned useconds; DESCRIPTION
The current process is suspended from execution for the number of microseconds specified by the argument. The actual suspension time may be an arbitrary amount longer because of other activity in the system or because of the time spent in processing the call. The routine is implemented by setting an interval timer and pausing until it occurs. The previous state of this timer is saved and restored. If the sleep time exceeds the time to the expiration of the previous timer, the process sleeps only until the signal would have occurred, and the signal is sent a short time later. This routine is implemented using setitimer(2); it requires eight system calls each time it is invoked. A similar but less compatible function can be obtained with a single select(2); it would not restart after signals, but would not interfere with other uses of setitimer. SEE ALSO
setitimer(2), getitimer(2), sigpause(2), ualarm(3), sleep(3), alarm(3) NOTES (PDP-11) On the PDP-11, setitimer(2) rounds the number of microseconds up to seconds resolution, therefore usleep doesn't give you any more resolu- tion than sleep(3). Select(2) offers clock resolution (usually 60Hz in the U.S.A. and 50Hz elsewhere) and so should be used instead. 4.3 Berkeley Distribution August 26, 1988 USLEEP(3)
Man Page