NAME    [Toc]    [Back]

       clock_gettime,  clock_settime  -  Obtains or sets the time
       for the specified clock (P1003.1b)

SYNOPSIS    [Toc]    [Back]

       #include <time.h>

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

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

LIBRARY    [Toc]    [Back]

       Realtime Library (librt.so, librt.a)

PARAMETERS    [Toc]    [Back]

       The clock type used to obtain the time for the clock  that
       is  set.  The CLOCK_REALTIME clock is supported and represents
 the TIME-OF-DAY clock for the system.  A pointer  to
       a timespec data structure.

DESCRIPTION    [Toc]    [Back]

       The  clock_gettime  function  returns the current time (in
       seconds and nanoseconds)  for  the  specified  clock.  The
       clock_settime  function  sets  the  specified  clock.  The
       CLOCK_REALTIME clock measures the amount of  time  elapsed
       since  00:00:00:00  January  1,  1970  Greenwich Mean Time
       (GMT), otherwise known as the  Epoch.  Time  values   that
       fall  between  two  non-negative  integer multiples of the
       resolution are truncated down to the smaller  multiple  of
       the resolution.

       You  must  have superuser privileges to use the clock_settime
 function.

RETURN VALUES    [Toc]    [Back]

       On a successful call to the clock_gettime or clock_settime
       functions, a value of 0 (zero) is returned.

       On  an  unsuccessful  call,  a value of -1 is returned and
       errno is set to indicate that an error occurred.

ERRORS    [Toc]    [Back]

       The clock_gettime and clock_settime functions  fail  under
       the  following  conditions: The clock_id argument does not
       specify a known clock.  The value pointed  to  by  the  tp
       argument  to  the  clock_settime  function  is outside the
       range for the given clock_id. The tp argument specified  a
       nanosecond  value  less than zero or greater than or equal
       to 1000 million.  The requesting process does not have the
       appropriate privilege to set the specified clock.

SEE ALSO    [Toc]    [Back]

       Functions:  time(1), clock_getres(3), ctime(3), timer_gettime(3)

       Guide to Realtime Programming



                                                 clock_gettime(3)