anchor.diff:                call getarg(i,ofile)
             elseif (tag(1:4).eq.'-geo') then
                 geo = 1
  +          elseif (tag(1:4).eq.'-haf') then
  +              i = i + 1
  +              call getarg(i,haff)
             elseif (tag(1:2).eq.'-h') then
                 call usage(' ')
             elseif (tag(1:2).eq.'-d') then
                 call usage('D')
  +          elseif (tag(1:2).eq.'-p') then
  +              p = 1
             else
                 call usage('!! Error: No option '//tag)
             endif
  
positive.code: C             need Green's functions for strike- and dip-slip components
                do 153 jj = 1,2
                    if (jj.eq.1) then
                        rak = 90.0d0
                        call o92rect(gfx,gfy,gfz,dstr,ddip,zobs,zflt,dip,
       1                             rak,wid,len,slip,vp,vs,dens)
                        A(i,j) = gfx*cost - gfy*sint
                        A(i+nobs,j) = gfx*sint + gfy*cost
                        A(i+2*nobs,j) = gfz
                    else
                        rak = 0.0d0
                        call o92rect(gfx,gfy,gfz,dstr,ddip,zobs,zflt,dip,
       1                             rak,wid,len,slip,vp,vs,dens)
                        A(i,j+nflt) = gfx*cost - gfy*sint
                        A(i+nobs,j+nflt) = gfx*sint + gfy*cost
                        A(i+2*nobs,j+nflt) = gfz
                    endif
    153         continue
  
negative.code: 
  C----------------------------------------------------------------------C
  
        SUBROUTINE gcmdln(fltf,obsf,smoof,smooth,damp,dimen,ofile,geo,
       1                  haff,p,dbg)
        IMPLICIT NONE
        CHARACTER*80 fltf,obsf,tag,smoof,ofile,haff
        INTEGER i,narg
        REAL*8 smooth,damp
        INTEGER dimen,geo,p,dbg
        fltf = 'none'
        obsf = 'none'
        smoof = 'none'
        ofile = 'none'
        haff  = 'none'
        dimen = 0
        smooth = -1.0d0
        damp = -1.0d0
        geo = 0
        p = 0
        dbg = 0
        narg = iargc()
        if (narg.eq.0) call usage('!! Error: no command line arguments')
        i = 0
  