USLEEP(3C) Standard C Library Functions USLEEP(3C)
NAME
usleep - suspend execution for interval in microseconds
SYNOPSIS
#include <unistd.h> int usleep(
useconds_t useconds);
DESCRIPTION
The
usleep() function suspends the caller from execution for the number
of microseconds specified by the
useconds argument. The actual
suspension time might be less than requested because any caught signal
will terminate
usleep() following execution of that signal's catching
routine. The suspension time might be longer than requested by an
arbitrary amount because of the scheduling of other activity in the
system.
If the value of
useconds is 0, then the call has no effect.
The use of the usleep function has no effect on the action or blockage
of any signal. In a multithreaded process, only the invoking thread is
suspended from execution.
RETURN VALUES
On completion,
usleep() returns 0. There are no error returns.
ERRORS
No errors are returned.
USAGE
The
usleep() function is included for its historical usage and is
Obsolete. The
nanosleep(3C) function is preferred over this function.
INTERFACE STABILITY
Obsolete Standard.
MT-LEVEL Safe.
SEE ALSO
nanosleep(3C),
sleep(3C),
unistd.h(3HEAD),
standards(7)STANDARDS
The
usleep() function is available in the following compilation
environments. See
standards(7).
+o X/Open Portability Guide Issue 4, Version 2 ("XPG4.2")
+o Version 2 of the Single UNIX Specification ("SUSv2")
+o Version 3 of the Single UNIX Specification ("SUSv3")
It is marked obsolete in Version 3 of the Single UNIX Specification
("SUSv3"), and was removed from IEEE Std 1003.1-2008 ("POSIX.1").
illumos August 16, 2014 illumos
