Function:     TIMER

Purpose:      Returns the cpu time and real time.

Category:     UTILITY

File:         timer.c

Author:       K.G. Begeman

Use:          CALL TIMER( CT ,       Input/Output   DOUBLE PRECISION
                          RT ,       Input/Output   DOUBLE PRECISION
                          MODE )        Input       INTEGER

              CT          Cpu time (in seconds) used since start of
                          programme (MODE=0) or CPU time used since
                          last call to TIMER (MODE<>0).
              RT          Real time (in seconds) since Jan 1 1970
                          (MODE=0) or real time used since last call
                          to TIMER (MODE<>0).
              MODE        If MODE=0 the current cpu time and real time
                          are returned otherwize the elapsed times are
                          returned.

Example:      PROGRAM TEST
              CHARACTER*80     MES
              DOUBLE PRECISION CT, RT
              ......
              CALL INIT
              CALL TIMER(CT,RT,0)
              ......
              ......
              CALL TIMER(CT,RT,1)
              WRITE(MES,'(''CPU TIME  :'',F10.4,'' SEC'')') CT
              CALL ANYOUT(3,MES)
              WRITE(MES,'(''REAL TIME :'',F10.4,'' SEC'')') RT
              CALL ANYOUT(3,MES)
              CALL FINIS
              STOP
              END

Updates:      Aug 17, 1991: KGB, Document created.
              Jul  7, 1999: JPT, Use CLOCKS_PER_SEC instead of CLK_TCK.
              May  4, 2007: JPT, Include conditional code for Apple Mac.