time

[daniel.lacerda@poli.usp.br]

  #include <sys/time.h>

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



DESCRIPTION

      When gettimeofday() is called under HP-UX, extensions apply to the
      time zone parameter, the return value, and errors.

      If the tzp parameter is not a null pointer, it is interpreted as a
      pointer to a struct timezone under HP-UX.  The struct timezone has
the
      following fields:

      tz_minuteswest   The number of minutes that the local time zone is
                       west of UTC.

      tz_dsttime       A flag that, if nonzero, indicates that Daylight
                       Savings Time (DST) applies locally during the
                       appropriate part of the year.

      Programs should use this time zone information only in the absence
of
      the TZ environment variable.

    Security Restrictions
      Only a user with appropriate privileges can set the time of day.



RETURN VALUE

      gettimeofday() return the following values under HP-UX:

            0   Successful completion.
           -1   Failure.  errno is set to indicate the error.



ERRORS

      If gettimeofday() fails, errno is set to the following value under
      HP-UX:

           [EFAULT]       An argument address referenced invalid memory.
                          The reliable detection of this error is
                          implementation dependent.



EXAMPLES

      The following HP-UX example calls gettimeofday() twice.  It then
      computes the lapsed time between the calls in seconds and
microseconds
      and stores the result in a timeval structure:

           struct timeval  first,
                           second,
                           lapsed;

           struct timezone tzp;

              gettimeofday (&first, &tzp);

           /* lapsed time */

              gettimeofday (&second, &tzp);

           if (first.tv_usec > second.tv_usec) {
              second.tv_usec += 1000000;
              second.tv_sec--;
           }

           lapsed.tv_usec = second.tv_usec - first.tv_usec;
           lapsed.tv_sec  = second.tv_sec  - first.tv_sec;


-- 
/*----------------------------------------------------------------        
  Daniel da Silva Lacerda
  Graduando em Engenharia Eletrica - daniel.lacerda@poli.usp.br
  Laboratorio de Tecnicas Inteligentes - www.lti.pcs.usp.br
  Escola Politecnica da USP - www.poli.usp.br
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