Manual Pages for UNIX Operating System command usage for man clock_settime

Standard C Library Functions                    clock_settime(3C)



NAME
     clock_settime, clock_gettime, clock_getres - high-resolution
     clock operations

SYNOPSIS
     #include 

     int clock_settime(clockid_t clock_id, const struct timespec *tp);


     int clock_gettime(clockid_t clock_id, struct timespec *tp);


     int clock_getres(clockid_t clock_id, struct timespec *res);


DESCRIPTION
     The  clock_settime()  function  sets  the  specified  clock,
     clock_id, to the value specified by tp. Time values that are
     between two consecutive non-negative  integer  multiples  of
     the  resolution of the specified clock are truncated down to
     the smaller multiple of the resolution.


     The clock_gettime() function returns the  current  value  tp
     for the specified clock, clock_id.


     The resolution of any  clock  can  be  obtained  by  calling
     clock_getres().  Clock  resolutions are system-dependent and
     cannot be set by a process. If the argument res is not NULL,
     the resolution of the specified clock is stored in the loca-
     tion pointed to by res. If res is NULL, the clock resolution
     is  not returned. If the time argument of clock_settime() is
     not a multiple of res, then the value is truncated to a mul-
     tiple of res.


     A  clock  may  be  systemwide  (that  is,  visible  to   all
     processes) or per-process (measuring time that is meaningful
     only within a process).


     A clock_id of CLOCK_REALTIME is defined  in  .  This
     clock represents the realtime clock for the system. For this
     clock, the values returned by clock_gettime() and  specified
     by  clock_settime() represent the amount of time (in seconds
     and nanoseconds) since the Epoch. Additional clocks may also
     be  supported.  The  interpretation of time values for these
     clocks is unspecified.





SunOS 5.11           Last change: 5 Feb 2008                    1






Standard C Library Functions                    clock_settime(3C)



     A clock_id of CLOCK_HIGHRES represents  the  non-adjustable,
     high-resolution  clock  for  the system. For this clock, the
     value returned by clock_gettime(3C) represents the amount of
     time  (in seconds and nanoseconds) since some arbitrary time
     in the past; it is not correlated in any way to the time  of
     day, and thus is not subject to resetting or drifting by way
     of   adjtime(2),   ntp_adjtime(2),   settimeofday(3C),    or
     clock_settime().  The time source for this clock is the same
     as that for gethrtime(3C).


     Additional clocks may also be supported. The  interpretation
     of time values for these clocks is unspecified.

RETURN VALUES
     Upon successful completion, 0  is returned. Otherwise, -1 is
     returned and errno is set to indicate the error.

ERRORS
     The  clock_settime(),  clock_gettime()  and   clock_getres()
     functions will fail if:

     EINVAL    The clock_id argument does  not  specify  a  known
               clock.


     ENOSYS    The  functions  clock_settime(),  clock_gettime(),
               and  clock_getres()  are  not  supported  by  this
               implementation.



     The clock_settime() function will fail if:

     EINVAL    The tp argument to clock_settime() is outside  the
               range  for  the given clock ID; or the tp argument
               specified a nanosecond value  less  than  zero  or
               greater than or equal to 1000 million.



     The clock_settime() function may fail if:

     EPERM    The requesting process does not have the  appropri-
              ate privilege to set the specified clock.


ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:





SunOS 5.11           Last change: 5 Feb 2008                    2






Standard C Library Functions                    clock_settime(3C)



     ____________________________________________________________________
    | ATTRIBUTE TYPE              | ATTRIBUTE VALUE                     |
    |_____________________________|_____________________________________|
    | Interface Stability         | Committed                           |
    |_____________________________|_____________________________________|
    | MT-Level                    | clock_gettime() is Async-Signal-Safe|
    |_____________________________|_____________________________________|
    | Standard                    | See standards(5).                   |
    |_____________________________|_____________________________________|


SEE ALSO
     time(2),    ctime(3C),     gethrtime(3C),     time.h(3HEAD),
     timer_gettime(3C), attributes(5), standards(5)









































SunOS 5.11           Last change: 5 Feb 2008                    3