Class: ProcessHelper::ProcessHelper

Inherits:
Object
  • Object
show all
Defined in:
lib/process-helper.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}) ⇒ ProcessHelper

opts can contain:

:print_lines

echo the STDOUT and STDERR of the process to STDOUT as well as capturing them.

:poll_rate

rate, in seconds (default is 0.25) to poll the capturered output for matching lines.



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# File 'lib/process-helper.rb', line 11

def initialize(opts = {})
  @opts =
    {
      :print_lines => false
    }.merge!(opts)
end

Instance Attribute Details

#exit_status ⇒ Object (readonly)

Returns the value of attribute exit_status.



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# File 'lib/process-helper.rb', line 6

def exit_status
  @exit_status
end

#pid ⇒ Object (readonly)

Returns the value of attribute pid.



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# File 'lib/process-helper.rb', line 6

def pid
  @pid
end

Instance Method Details

#get_log(which) ⇒ Object

Gets an array containing all the lines for the specified output stream. which can be either of:

  • :out

  • :err



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# File 'lib/process-helper.rb', line 59

def get_log(which)
  log = _get_log(which)
  log.nil? ? [] : log.to_a
end

#get_log!(which) ⇒ Object

Gets an array containing all the lines for the specified stream, emptying the stored buffer. which can be either of:

  • :out

  • :err



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# File 'lib/process-helper.rb', line 68

def get_log!(which)
  log = _get_log(which)
  log.nil? ? [] : log.drain
end

#kill(signal = 'TERM') ⇒ Object

Send the specified signal to the wrapped process.



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# File 'lib/process-helper.rb', line 51

def kill(signal = 'TERM')
  Process.kill(signal, @pid)
end

#start(command_and_args = [], output_to_wait_for = nil, wait_timeout = nil, env = {}, opts = {}) ⇒ Object

Starts a process defined by ‘command_and_args`

command_and_args

Array with the first element as the process to start, the rest being the parameters to the new process.

output_to_wait_for

Regex containing expected output, start will block until a line of STDOUT matches this regex, if this is nil, then no waiting occurs.

wait_timeout

Timeout while waiting for particular output.

env

Hash of extra environment variables with which to start the process.



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# File 'lib/process-helper.rb', line 23

def start(command_and_args = [], output_to_wait_for = nil, wait_timeout = nil, env = {}, opts = {})
  out_r, out_w = IO.pipe
  @out_log = ProcessLog.new(out_r, @opts).start
  if opts[:stderr]
    err_r, err_w = IO.pipe
    @err_log = ProcessLog.new(err_r, @opts).start
  else
    err_w = out_w
  end
  @pid = spawn(env, *command_and_args, :out => out_w, :err => err_w)
  out_w.close
  err_w.close if opts[:stderr]
  @out_log.wait_for_output(output_to_wait_for, :timeout => wait_timeout) unless output_to_wait_for.nil?
end

#wait_for_exit ⇒ Object

returns true if the process exited with an exit code of 0.



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# File 'lib/process-helper.rb', line 39

def wait_for_exit
  @out_log.wait
  @err_log.wait unless @err_log.nil?

  Process.wait(@pid)
  @exit_status = $CHILD_STATUS

  @pid = nil
  @exit_status == 0
end

#wait_for_output(which, regexp, opts = {}) ⇒ Object

Blocks the current thread until the specified regex has been matched in the output. which can be either of:

  • :out

  • :err

opts can contain:

:timeout

timeout in seconds to wait for the specified output.

:poll_rate

rate, in seconds (default is 0.25) to poll the capturered output for matching lines.



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# File 'lib/process-helper.rb', line 80

def wait_for_output(which, regexp, opts = {})
  _get_log(which).wait_for_output(regexp, opts)
end