USLEEP(1) The SuSE boot concept USLEEP(1)NAME
Usleep - sleep for the specified number of microseconds
SYNOPSIS
usleep [ usec ]
DESCRIPTION
usleep pauses for the number of usec microseconds. The default is 1 microsecond. If 0 microseconds are specified sched_yield(2) is called.
BUGS
The usleep program uses the usleep(3) function and therefore shows the same weaknesses by any system activity.
SEE ALSO usleep(3), sleep(1), sleep(3), sched_yield(2).
COPYRIGHT
2001 Werner Fink, 2001 SuSE GmbH Nuernberg, Germany.
AUTHOR
Werner Fink <werner@suse.de>
3rd Berkeley Distribution Jan 31, 2001 USLEEP(1)
Check Out this Related Man Page
USLEEP(3) Linux Programmer's Manual USLEEP(3)NAME
usleep - suspend execution for microsecond intervals
SYNOPSIS
#include <unistd.h>
int usleep(useconds_t usec);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
usleep(): _BSD_SOURCE || _XOPEN_SOURCE >= 500
DESCRIPTION
The usleep() function suspends execution of the calling process for (at least) usec microseconds. The sleep may be lengthened slightly by
any system activity or by the time spent processing the call or by the granularity of system timers.
RETURN VALUE
0 on success, -1 on error.
ERRORS
EINTR Interrupted by a signal; see signal(7).
EINVAL usec is not smaller than 1000000. (On systems where that is considered an error.)
CONFORMING TO
4.3BSD, POSIX.1-2001. POSIX.1-2001 declares this function obsolete; use nanosleep(2) instead. POSIX.1-2008 removes the specification of
usleep().
On the original BSD implementation, and in glibc before version 2.2.2, the return type of this function is void. The POSIX version returns
int, and this is also the prototype used since glibc 2.2.2.
Only the EINVAL error return is documented by SUSv2 and POSIX.1-2001.
NOTES
The type useconds_t is an unsigned integer type capable of holding integers in the range [0,1000000]. Programs will be more portable if
they never mention this type explicitly. Use
#include <unistd.h>
...
unsigned int usecs;
...
usleep(usecs);
The interaction of this function with the SIGALRM signal, and with other timer functions such as alarm(2), sleep(3), nanosleep(2),
setitimer(2), timer_create(2), timer_delete(2), timer_getoverrun(2), timer_gettime(2), timer_settime(2), ualarm(3) is unspecified.
SEE ALSO alarm(2), getitimer(2), nanosleep(2), select(2), setitimer(2), sleep(3), ualarm(3), time(7)COLOPHON
This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
2007-07-26 USLEEP(3)