usleep (3)

NAME

       usleep - suspend execution for microsecond intervals

SYNOPSIS

       #include <unistd.h>

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

DESCRIPTION

       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

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

ERRORS

       EINTR  Interrupted by a signal.

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

CONFORMING TO

       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

       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       This function is obsolete.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

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

                                  2001-04-02                         usleep(3)