NAME    [Toc]    [Back]

       usleep - suspend execution for microsecond intervals

SYNOPSIS    [Toc]    [Back]

       #include <unistd.h>

       void usleep(unsigned long usec);
       int usleep(unsigned long usec); /* SUSv2 */

DESCRIPTION    [Toc]    [Back]

       The  usleep()  function	suspends  execution of the calling process for
       usec microseconds.  The sleep may be lengthened slightly by any	system
       activity or by the time spent processing the call.

RETURN VALUE    [Toc]    [Back]

       None (BSD). Or: 0 on success, -1 on error (SUSv2).

ERRORS    [Toc]    [Back]

       EINTR  Interrupted by a signal.

       EINVAL usec  is	not  smaller  than 1000000.  (On systems where that is
	      considered an error.)

CONFORMING TO    [Toc]    [Back]

       BSD 4.3.  The SUSv2 version returns int, and this is also the prototype
       used  by  glibc	2.2.2.	 Only the EINVAL error return is documented by
       SUSv2.

NOTES    [Toc]    [Back]

       The interaction of this function with SIGALRM and other timer functions
       such  as  sleep(),  alarm(),  setitimer(),  nanosleep() is unspecified.
       This function is obsolete. Use nanosleep(2) or setitimer(2) instead.

SEE ALSO    [Toc]    [Back]

       alarm(2), getitimer(2), nanosleep(2), select(2), setitimer(2), sleep(3)



				  2001-04-02			     USLEEP(3)