SLEEP(3)               FreeBSD Library Functions Manual               SLEEP(3)

NAME
     sleep - suspend thread execution for an interval measured in seconds

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     unsigned int
     sleep(unsigned int seconds);

DESCRIPTION
     The sleep() function suspends execution of the calling thread until
     either seconds seconds have elapsed or a signal is delivered to the
     thread and its action is to invoke a signal-catching function or to
     terminate the thread or process.  System activity may lengthen the sleep
     by an indeterminate amount.

     This function is implemented using nanosleep(2) by pausing for seconds
     seconds or until a signal 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
     If the sleep() function returns because the requested time has elapsed,
     the value returned will be zero.  If the sleep() function returns due to
     the delivery of a signal, the value returned will be the unslept amount
     (the requested time minus the time actually slept) in seconds.

SEE ALSO
     nanosleep(2), usleep(3)

STANDARDS
     The sleep() function conforms to IEEE Std 1003.1-1990 ("POSIX.1").

HISTORY
     A sleep() function appeared in Version 7 AT&T UNIX.

FreeBSD 13.1-RELEASE-p6        February 13, 1998       FreeBSD 13.1-RELEASE-p6