Ruby/File Directory/StringIO
Материал из Wiki.crossplatform.ru
Содержание |
Find the fifth byte
require "stringio" def fifth_byte(file) file.seek(5) file.read(1) end fifth_byte(StringIO.new("123456")) # => "6"
Performing Random Access on Read-Once Input Streams
require "socket" require "stringio" sock = TCPSocket.open("www.example.ru", 80) sock.write("GET /\n") file = StringIO.new(sock.read) file.read(10) # => "<HTML>\r\n<H" file.rewind file.read(10) # => "<HTML>\r\n<H" file.pos = 90 file.read(15) # => " this web page "
Pretending a String is a File
require "stringio" s = StringIO.new %{I am the very model of a modern major general. I"ve information vegetable, animal, and mineral.} puts s.pos # => 0 s.each_line { |x| puts x } puts s.eof? # => true puts s.pos # => 95 puts s.rewind puts s.pos # => 0 puts s.grep /general/
push data to string
require "stringio" s = StringIO.new s << "A string" s.read s << ", and more." s.rewind s.read # => "A string, and more."
Redirecting Standard Input or Output
#!/usr/bin/env ruby # redirect_stdout.rb require "stringio" new_stdout = StringIO.new $stdout = new_stdout puts "Hello, hello." puts "I"m writing to standard output." $stderr.puts "#{new_stdout.size} bytes written to standard ouput so far." $stderr.puts "AAA" $stderr.puts new_stdout.string $ ruby redirect_stdout.rb
Write to a string
require "stringio" s = StringIO.new s.write("Treat it like a file.") s.rewind s.write("Act like it"s") s.string # => "Act like it"s a file."
YAML.dump
require "stringio" require "yaml" s = StringIO.new YAML.dump(["A list of", 3, :items], s) puts s.string
