Copyright 2014 Garrett D'Amore <garrett@damore.org>
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.Dd "Aug 16, 2014" .Dt USLEEP 3C .Os .Sh NAME .Nm usleep .Nd suspend execution for interval in microseconds .Sh SYNOPSIS n unistd.h .Ft int .Fn usleep "useconds_t useconds" .Sh DESCRIPTION The .Fn usleep function suspends the caller from execution for the number of microseconds specified by the .Fa useconds argument. The actual suspension time might be less than requested because any caught signal will terminate .Fn 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. .Lp If the value of .Fa useconds is 0, then the call has no effect. .Lp 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. .Sh RETURN VALUES On completion, .Fn usleep returns 0. There are no error returns. .Sh ERRORS No errors are returned. .Sh USAGE The .Fn usleep function is included for its historical usage and is Obsolete. The .Xr nanosleep 3C function is preferred over this function. .Sh INTERFACE STABILITY .Sy Obsolete Standard . .Sh MT-LEVEL .Sy Safe . .Sh SEE ALSO .Xr nanosleep 3C , .Xr sleep 3C , .Xr unistd.h 3HEAD , .Xr standards 5 .Sh STANDARDS The .Fn usleep function is available in the following compilation environments. See .Xr standards 5 . .Lp l -bullet -compact t .St -xpg4.2 t .St -susv2 t .St -susv3 .El .Lp It is marked obsolete in .St -susv3 , and was removed from .St -p1003.1-2008 .