Class: Fig::ExternalProgram

Inherits:
Object
  • Object
show all
Defined in:
lib/fig/external_program.rb

Class Method Summary collapse

Class Method Details

.capture(command_line, input = nil) ⇒ Object


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# File 'lib/fig/external_program.rb', line 40

def self.capture(command_line, input = nil)
  output = nil
  errors = nil

  result = popen(*command_line) do
    |stdin, stdout, stderr|

    if ! input.nil?
      stdin.puts input # Potential deadlock if input is bigger than pipe size.
    end
    stdin.close

    output = StringIO.new
    errors = StringIO.new
    input_to_output = {stdout => output, stderr => errors}
    while ! input_to_output.empty?
      ready, * = IO.select input_to_output.keys
      ready.each do
        |handle|

        begin
          # #readpartial() is busted in that it is returning a byte array in
          # a String with a bogus Encoding, even though the bytes may not be
          # valid in the Encoding.
          input_to_output[handle] << handle.readpartial(4096)
        rescue EOFError
          input_to_output.delete handle
        end
      end
    end
  end

  output_string = string_io_byte_array_to_utf8_string output
  errors_string = string_io_byte_array_to_utf8_string errors

  return output_string, errors_string, result
end

.popen(*cmd) ⇒ Object


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# File 'lib/fig/external_program.rb', line 10

def self.popen(*cmd)
  exit_code = nil

  options = {}
  stdin_read, stdin_write = IO.pipe Encoding::UTF_8, Encoding::UTF_8
  options[:in] = stdin_read
  stdin_write.sync = true

  stdout_read, stdout_write = IO.pipe Encoding::UTF_8, Encoding::UTF_8
  options[:out] = stdout_write

  stderr_read, stderr_write = IO.pipe Encoding::UTF_8, Encoding::UTF_8
  options[:err] = stderr_write

  popen_run(
    cmd,
    options,
    [stdin_read, stdout_write, stderr_write],
    [stdin_write, stdout_read, stderr_read],
  ) do
    |stdin, stdout, stderr, wait_thread|

    yield stdin, stdout, stderr

    exit_code = wait_thread.value
  end

  return exit_code
end