anchor.diff:                ktrg = 1
                 i = i + 1
                 call getarg(i,trgfile)
  -              ptr = index(trgfile,'/')
  +              ptr = index(trgfile,'/') ! check format of argument
                 if (ptr.ne.0) then
                     ktrg = 2
                 endif
  
positive.code:           if (ktrg.eq.0) then
                write(*,*) '!! Error: -normal, -shear, and -coul '//
       1                             'require target faults'
                call usage('!! Use -trg TRGFILE')
            elseif (ktrg.eq.1) then
                inquire(file=trgfile,EXIST=ex)
                if (.not.ex) then
  
negative.code:   221     continue
    222 continue 
        do 225 f = 1,nflt
            if (xy.eq.0) then
                call ddistaz(dist,az,evlo(f),evla(f),stlo,stla)
                dist = dist*6.371d6
            else
                delx = (stlo-evlo(f))*1.0d3
                dely = (stla-evla(f))*1.0d3
                dist = dsqrt(delx*delx + dely*dely)
                az = datan2(delx,dely)
            endif
            x = dist*( dcos(az-d2r*str(f)))
            y = dist*(-dsin(az-d2r*str(f)))
            if (flttyp.eq.0) then
  