c Simple program to read Geosat Wind/Wave binary-integer data files to
c produce a text listing.  With the optional "-s" switch on the command line
c the program will internally perform the necessary byte-swapping for a PC
c or VAX system.  
c
c John L. Lillibridge
c NOAA Lab. for Satellite Altimetry
c 11/10/99
c
      program dump_ww


      implicit none


      integer*4 nargs,iargc
      integer*4 lat,lon,sec,ios,irec
      integer*2 usec,swh,sig0,att,flag,wind_cw,wind_br


      real*8 rlat,rlon,rsec
      character*80 fn
      logical swap
c
c iagrc() and getarg(n,string) are Fortran library functions
c which return the number of command line arguments, and the character
c string of the nth argument, respectively.
c
      nargs=iargc()
      if(nargs.lt.1.or.nargs.gt.2)then
        write(6,*)'Usage: dump_ww [-s] ww_file'
        write(6,*)' -s to do [optional] byte-swapping (PC/Vax)'
        stop
      endif
c
c Process command line arguments, and check for the "-s" switch.
c
      call getarg(1,fn)
      if(fn.eq.'-s')then
        swap=.True.
        call getarg(2,fn)
      else
        swap=.False.
      endif
c
c File format is direct-access, integer-binary, 26-byte record length.
c
      open(10,file=fn,access='direct',recl=26,iostat=ios,err=10)


      irec=1
      do while(ios.eq.0)
        read(10,rec=irec,iostat=ios,err=10)lat,lon,sec,
     &      usec,swh,sig0,att,flag,wind_cw,wind_br
c
c Do byte-swapping if needed
c
        if(swap)then
          call swap4(lat)
          call swap4(lon)
          call swap4(sec)
          call swap2(usec)
          call swap2(swh)
          call swap2(sig0)
          call swap2(att)
          call swap2(flag)
          call swap2(wind_cw)
          call swap2(wind_br)
        endif
c
c Convert lat/lon/time to real numbers
c
        rlat=lat*1d-6
        rlon=lon*1d-6
        rsec=sec+usec*1d-6


        write(6,'(2(f10.6,x),f15.6,5i7,x,o6)')
     &       rlat,rlon,rsec,swh,sig0,att,wind_cw,wind_br,flag


        irec=irec+1
      enddo
      stop
c
c HP-UX f77 returns error code 922 for end-of-file...
c
10      if(ios.ne.922)then
        write(6,*)'I/O error:',ios
        stop
      endif
      end


c-----------------------------------------------------------------


      subroutine swap4(in)


      implicit none
      byte in(4),b


      b=in(1)
      in(1)=in(4)
      in(4)=b
      b=in(2)
      in(2)=in(3)
      in(3)=b


      return
      end


c-----------------------------------------------------------------


      subroutine swap2(in)


      implicit none
      byte in(2),b


      b=in(1)
      in(1)=in(2)
      in(2)=b


      return
      en