anchor.diff:  
   C----------------------------------------------------------------------C
   
  -      SUBROUTINE gcmdln(ifile,ofile,c,cmdin,p)
  +      SUBROUTINE gcmdln(ifile,ofile,c,cmdin,p,debug)
         IMPLICIT NONE
         CHARACTER*30 ifile,ofile,tag
         INTEGER i,narg,c,p
         REAL*8 cmdin(4)
  +      LOGICAL debug
         ifile = 'none'
         ofile = 'none'
  +      debug = .false.
         c = 0
         p = 1
         narg = iargc()
  
positive.code:       PARAMETER (pi=4.0d0*datan(1.0d0),r2d=1.8d2/pi,radius=6371.0d0)
        REAL*8 lon1,lat1,lon2,lat2,dist,az,cmdin(4)
        CHARACTER*30 ifile,ofile
        INTEGER c,p,input
        LOGICAL ex
  
  C----
  C Parse command line and read options
  C----
        call gcmdln(ifile,ofile,c,cmdin,p)
  
  C----
  C Check inputs are valid
  C----
        if (c.eq.1) goto 103
        if (ifile.eq.'none') then
            write(*,*) '!! Error: Input lon1 lat1 lon2 lat2 file ',
  
negative.code:           endif
            goto 901
    902 continue
        if (debug) then
            write(0,*) 'Debugging output turned on in gcmdln'
            write(0,*) 'Leaving gcmdln'
        endif
        RETURN
        END
  
  