RUBYファイル読み書き

11.読み書き
標準入力ストリームひょうじゅんにゅうりょくストリーム:getsよみとりファイル
              File.open("hello.rb","r") do |file|
               while line  = file.gets

1.       
    #p1
    myFile = File.new("f:\\ruby\\mycode\\hello.rb","w");
    myFile.puts "puts 'aa'"
    myFile.puts "puts 'bb'"
    myFile.close #  close            。
    windows    "\\"
    
      hello.rb        
        ：File.new("hello.rb","w")
        ：File.delete("")
        ：File.open("hello.rb","r") do |file|
                while line = file.gets   #     
                   puts line
                end
              end
    #   
    print "Please input a file name:"
    filename = gets
    if filename &&!filename.empty?#    
        filename = filename[0,filename.length-1]
        #        "
"
    else
        print "the file name can't be null!"
        exit(1)
    end
    
    if File.exist?(filename)
        puts "=========#{filename}========="
        File.open(filename,"r") do |file|
             while line = file.gets
                puts line
             end
        end
        puts "=================="
    else
        puts "the program can't find the file #{filename}"
    end
    print "Press any key to contiue..."
    gets
    
    
    #   
    puts "======================================"
    puts "This program is about Ruby write file."
    puts "======================================"
    print "Please input file name: "
    filename=gets
    if filename&&!filename.empty?
        filename=filename[0, filename.length-1]
    else
        puts "The file name can't been null!!"
        exit 1;
    end
    file=nil
    unless File.exist?(filename)#          
       puts "The system cannot find the file specified!"
       print "[C] to create a new file and [E] to exit the program: "
       option=gets
       if option&&!option.empty?
          option=option.chomp#  "
"
       else
          puts "bye!"
          exit 1;
       end
       case option.downcase
       when "c" : file=File.new(filename, "w")
       when "e" : exit 0
       else
          puts "Invalid arguments!! The program has stop. "
          exit 0
       end
    else
        file=File.new(filename, "w")
    end
    print "Now please input content: "
    content=gets
    file.print content
    file.close
    print "Press any key to continue...."
    gets

puts line#ファイル内容を印刷
               end
             end
標準出力ストリーム:puts printの違いは、putsがパラメータの後ろに戻り改行を追加することであり、printはprintf(「Number:%5.2 f,String:%s」,1.23,「hello」)を追加しないという構文はcと同じであり、%5.2 fが1.23に一致するとは言わない
%s一致文字列