NAME    [Toc]    [Back]

       usleep - Suspend execution for an interval of time

SYNOPSIS    [Toc]    [Back]

       #include <unistd.h>

       int usleep(
               useconds_t useconds );

       The  following  function  declaration  does not conform to
       current standards and is supported only for backward  compatibility:


       #include <unistd.h>

       void usleep(
               unsigned useconds );

LIBRARY    [Toc]    [Back]

       Standard C Library (libc)

STANDARDS    [Toc]    [Back]

       Interfaces  documented  on  this reference page conform to
       industry standards as follows:

       usleep():  XPG4-UNIX

       Refer to the standards(5) reference page for more information
 about industry standards and associated tags.

PARAMETERS    [Toc]    [Back]

       Specifies the number of microseconds to sleep.

DESCRIPTION    [Toc]    [Back]

       The  usleep()  function  suspends the current process from
       execution for the number of microseconds specified by  the
       useconds  parameter. Because of other activity in the system,
 or because of the time spent in processing the  call,
       the actual suspension time might be longer than specified.

       The useconds parameter must be less  than  1,000,000.   If
       the  value  of useconds is 0 (zero), the usleep() function
       has no effect.

       In a multithreaded environment, the  sleep()  function  is
       redefined to suspend the calling thread.

RETURN VALUES    [Toc]    [Back]

       On  successful completion, the usleep() function returns 0
       (zero). Otherwise, it returns -1 and sets errno  to  indicate
 the error.

ERRORS    [Toc]    [Back]

       The  usleep()  function sets errno to the specified values
       for the following conditions: The  interval  specified  in
       the useconds parameter exceeds 1,000,000 microseconds.

SEE ALSO    [Toc]    [Back]

       Functions:    getitimer(2),    sigaction(2),    sigvec(2),
       alarm(3), sleep(3)

       Standards: standards(5)



                                                        usleep(3)