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USLEEP(3)                BSD Library Functions Manual                USLEEP(3)

NAME
     usleep -- suspend thread execution for an interval measured in microseconds

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     int
     usleep(useconds_t useconds);

DESCRIPTION
     The usleep() function suspends execution of the calling thread until either useconds microseconds have
     elapsed or a signal is delivered to the thread whose action is to invoke a signal-catching function or
     to terminate the thread or process.  The actual time slept may be longer, due to system latencies and
     possible limitations in the timer resolution of the hardware.

     This function is implemented, using nanosleep(2), by pausing for useconds microseconds or until a sig-nal signal
     nal occurs.  Consequently, in this implementation, sleeping has no effect on the state of process
     timers and there is no special handling for SIGALRM.

RETURN VALUES
     The usleep() function returns the value 0 if successful; otherwise the value -1 is returned and the
     global variable errno is set to indicate the error.

ERRORS
     The usleep() function will fail if:

     [EINTR]            A signal was delivered to the process and its action was to invoke a signal-catching
                        function.

SEE ALSO
     nanosleep(2), sleep(3)

HISTORY
     The usleep() function appeared in 4.3BSD.

BSD                            February 13, 1998                           BSD