gettimeofday

Purpose

     Obtains current time.

Library

     Berkeley Library (libbsd.a)

Syntax

     #include <bsd/sys/time.h>

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

Description

     The  gettimeofday subroutine  gets the  current Greenwich
     time and the current time zone.  The time is expressed in
     seconds and  microseconds.  If  tzp equals 0,  the system
     omits the time zone.

     The tp  parameter points to a  timeval structure, defined
     in the file bsd/sys/time.h.   This structure contains the
     following members:

          long  tv_sec;          /* Seconds since Jan. 1, 1970     */
          long  tv_usec;         /* Microseconds to add to seconds */

     The tzp parameter points to a timezone structure, defined
     in the bsd/sys/time.h file.   This structure contains the
     following members:

          int   tz_minuteswest;  /* Time west of Greenwich in minutes */
          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.

     To set the current time, use  the time system call or the
     date command.

Return Value

     If the  call succeeds, a value  of 0 is returned.   If an
     error occurs,  a value  of -1 is  returned, and  an error
     code is placed in the global variable errno.

Diagnostics

     If an  argument address points  to an invalid  segment of
     memory, the system issues a SIGSEGV.  If the process does
     not respond, it is terminated with a core dump.

Related Information

     In this book:  "ctime, localtime, gmtime, asctime, tzset"
     and "time."

     The date command in  AIX Operating System Commands Refer-
     ence.

     The discussion of timed in Interface Program for use with
     TCP/IP.