DouKaku?

def dir8(f)
  ch = Hash[*(w = f[1].split(//)).zip((0..vmax = w.length-1).to_a).flatten]
  hrz, vrt = {1=>"右", 0=>"", -1=>"左"}, {1=>"下", 0=>"", -1=>"上"}
  va = []  #--- vector array
  row = -1
  open(f[0]) {|fin|
    while (line = fin.gets) != "\n"
      row += 1
      line = line[0..-2].split(//).map {|i|ch[i]}
      (0...line.size).each {|col|
        item = [col, row, line[col]]
        (0...va.size).each {|i|
          va[i] = nextVector(va[i], [vmax, hrz, vrt]) if va[i][0..2] === item
        }
        -1.upto(1){|ic|  #--- make vector around
          -1.upto(1){|ir|
            dv = (ir > 0 || ic + ir > 0 ? 1 : -1)
            va << [col + ic * dv, row + ir * dv, line[col] + dv, ic, ir, 0, dv]
          }
        }
      }
      va = va.select {|i|i if (i[1] > row) || (i[0]+i[1] > 0)}
    end
  }
end

def nextVector(a, par)
  x, y, val, vx, vy, len, dv = a
  vmax, hrz, vrt = par
  if (len += 1) == vmax
    hosei = (dv == -1 ? 0 : -1) * vmax
    p [x + vx * hosei, y + vy * hosei, hrz[vx] + vrt[vy]]
  end
  [x + vx * dv, y + vy * dv, val + dv, vx, vy, len, dv]
end

if $FILE != $0
  dir8(ARGV)
end

#ruby -Ku dir8.rb dir8.in "ウオリ"