gettimeofday(2)                                   gettimeofday(2)



     NAME
          gettimeofday, settimeofday - get/set date and time

     SYNOPSIS
          #include <sys/time.h>

          gettimeofday(tp,tzp)
          struct timeval *tp;
          struct timezone *tzp;

          settimeofday(tp,tzp)
          struct timeval *tp;
          struct timezone *tzp;

     DESCRIPTION
          The system's notion of the current Greenwich time and the
          current time zone is obtained with the gettimeofday call,
          and set with the settimeofday call.  The time is expressed
          in seconds and microseconds since midnight (0 hour), January
          1, 1970.  The resolution of the system clock is hardware
          dependent, and the time may be updated continuously or in
          ``ticks.'' If tzp is zero, the time zone information will
          not be returned or set.

          The structures pointed to by tp and tzp are defined in
          <sys/time.h> as:

          struct timeval {
               long  tv_sec;     /* seconds since Jan. 1, 1970 */
               long  tv_usec;    /* and microseconds */
          };

          struct timezone {
               int  tz_minuteswest;  /* of Greenwich */
               int  tz_dsttime;      /* type of dst correction
                                        to apply */
          };

          The timezone structure indicates the local time zone
          (measured in minutes of time westward from Greenwich), and a
          flag that, if nonzero, indicates that Daylight Saving time
          applies locally during the appropriate part of the year.

          Only the super-user may set the time of day or time zone.

     RETURN
          A 0 return value indicates that the call succeeded.  A -1
          return value indicates an error occurred, and in this case
          an error code is stored into the global variable errno.

     ERRORS
          The following error codes may be set in errno:



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     gettimeofday(2)                                   gettimeofday(2)



          [EFAULT]       An argument address referenced invalid
                         memory.

          [EPERM]        A user other than the super-user attempted to
                         set the time.

     SEE ALSO
          date(1), adjtime(2), ctime(3).















































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