右側折り返し（Rubyの場合）

maxlength = 72

File.open("../data_c.txt","r"){|f|
  f.each{|line|
    line.chomp!
    (line.size/maxlength).times{|i|
      line[maxlength*(i+1)+i,0] = "\n"
    }
    print line+"\n"
  }
}