Dir.chdir( “/Users/weston” )  #进入目录
home =Dir.pwd  #=> “/Users/weston/” * 显示目录
Dir.mkdir( “/Users/weston/” )  ＃创建目录，和*nix命令一样吧
Dir.rmdir( “/Users/weston/test” ) # 删除目录
Dir.mkdir( “/Users/weston/test”,755 ) #常见目录，设置权限
d = Dir.entries( “/Users/weston” ).each { |e| puts e } #=> Array
d2 = d.delete_if{ |e| e=~ /^\..*/} #=>这样出来的就是不包含隐藏文件了
dir = Dir.open( “/Users/weston” ) # => #<Dir:0x1cd784>
dir.path # => “/Users/weston”
dir.tell # => “.”
dir.read # => 1
dir.tell # => “..”
dir.rewind # => rewind to beginning
dir.each { |e| puts e } # puts each entry in dir
dir.close # => close stream

file = File.new( “file.rb”, “w” ) # => #<File:file.rb> 其中的w是表示可以写，还有很多模式：r, r+, w, w+, a, a+,b
file = File.open( “sonnet_129.txt” )
file.each { |line| print “#{file.lineno}. ”, line } #lineno 是行号
file.close
File.new( “books.txt”, “w” )
File.rename( “books.txt”, “chaps.txt” )
File.delete( “chaps.txt” )