Module: Expectr::Child

Includes:
Interface
Included in:
Adopt
Defined in:
lib/expectr/child.rb,
lib/expectr/errstr.rb

Overview

Public: The Expectr::Child Module defines the interface for interacting with child processes.

Defined Under Namespace

Modules: Errstr

Instance Method Summary collapse

Methods included from Interface

#prepare_interact_interface

Instance Method Details

#init_interface(args) ⇒ Object

Public: Initialize the Expectr interface, spawning a sub-process attaching to STDIN and STDOUT of the new process.

args - A Hash containing arguments to Expectr. Only :cmd is presently

used for this function.
:cmd - A String or File referencing the application to launch.

Returns nothing. Raises TypeError if args is anything other than String or File.



20
21
22
23
24
25
26
27
28
29
30
 
# File 'lib/expectr/child.rb', line 20

def init_interface(args)
  cmd = args[:cmd]
  cmd = cmd.path if cmd.kind_of?(File)

  unless cmd.kind_of?(String)
    raise(TypeError, Errstr::STRING_FILE_EXPECTED)
  end

  @stdout,@stdin,@pid = PTY.spawn(cmd)
  @stdout.winsize = $stdout.winsize if $stdout.tty?
end

#kill!(signal = :TERM) ⇒ Object

Public: Send a signal to the running child process.

signal - Symbol, String or FixNum indicating the symbol to be sent to the

running process. (default: :TERM)

Returns a boolean indicating whether the process was successfully sent the signal. Raises ProcessError if the process is not running (@pid = 0).



40
41
42
43
44
45
 
# File 'lib/expectr/child.rb', line 40

def kill!(signal = :TERM)
  unless @pid > 0
    raise(ProcessError, Errstr::PROCESS_NOT_RUNNING)
  end
  Process::kill(signal.to_sym, @pid) == 1
end

#output_loop ⇒ Object

Public: Read the output of the child process, force UTF-8 encoding, then append to the internal buffer and print to $stdout if appropriate.

Returns nothing.



68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
 
# File 'lib/expectr/child.rb', line 68

def output_loop
  while @pid > 0
    unless select([@stdout], nil, nil, @timeout).nil?
      buf = ''

      begin
        @stdout.sysread(@buffer_size, buf)
      rescue Errno::EIO, EOFError #Application is not running
        @pid = 0
        @thread.wakeup if @thread
        return
      end
      process_output(buf)
    end
  end
end

#send(str) ⇒ Object

Public: Send input to the active child process.

str - String to be sent.

Returns nothing. Raises Expectr::ProcessError if the process is not running (@pid = 0).



53
54
55
56
57
58
59
60
61
62
 
# File 'lib/expectr/child.rb', line 53

def send(str)
  begin
    @stdin.syswrite str
  rescue Errno::EIO, EOFError # Application is not running
    @pid = 0
  end
  unless @pid > 0
    raise(Expectr::ProcessError, Errstr::PROCESS_GONE)
  end
end

#winsize ⇒ Object

Public: Return the PTY’s window size.

Returns a two-element Array (same as IO#winsize)



88
89
90
 
# File 'lib/expectr/child.rb', line 88

def winsize
  @stdout.winsize
end