processcontroller 0.0.2

Replacement for pexpect

Fast Start

Install the package:

pip install --user processcontroller

Import the main class:

from processcontroller import ProcessController

Create a new instance:

process_controller = ProcessController()

The ProcessController() instance

Methods

• The run() method:

  process_controller.run(command, options)
  
  Run a program (command and options detailed below)

• The send() method:

  process_controller.send(str|bytes)
  
  Send a string or bytearray to the subprogram stdin, you will usually use it inside a callback or in detached state

• The close() method:

  process_controller.close()
  
  Close the stdin of the subprogram so it reaches EOF, you will usually use it inside a callback or in detached state

• The kill() method:

  process_controller.kill()
  
  Sends signal SIGKILL to the subprogram, the return_value should be (pid, 9) after that.
  (this should not be so used to be honest)

Attributes

• return_value

  is the return value of the subprogram it will be - (0, 0) if running - (pid, status) if terminated

Function Parameters

ProcessController.run()

command

The command parameter must be an array like:

['/usr/bin/python', 'file.py']

options

Currently, it supports the following keys, ‘when’, ‘input’, ‘echo’ and ‘detached’

• when:

  This key is used to listen to events occuring on the STDOUT of the subprogram The value have to be an array of events The “event” is in fact a match for some pattern:

  'when': [
     ['^SomeRegex.*\n', callback],
     ['^An other one.\n', cb]
     ['^prompt>\$ $', cb]
  ]

  Be careful about the ending line, the match will be called each time a char is added to the buffer, this helps matching prompts maybe I’ll add an option to avoid such an expansive operation in the future Every time a ‘n’ char is found, the line is treated once and reseted to ‘’

  The callbacks will be called with two arguments: the ProcessController instance, and the matched string:

  def callback(processcontroller, string)

  You can automates user inputs in your callback when required by the subprogram using the send function of your ProcessController instance:

  def cb(p, s):
     c.send('some input')

• input:’

  This key is used to pre-fill the stdin of a subprogram before running it:

  pc = ProcessController()
  pc.run(['/bin/bash'], {
     'input': 'echo test && exit'
  })

  You can set an array of input:

  'input': ['one', 'two', 'three']  # sends "one\ntwo\nthree\n"
  
  You can input str or bytes, conversion is handled for you

• echo:

  This key is a boolean that defaults to False. When set to True, the ProcessController will print the input sent to your subprogram where it has been asked

• detached:

  This key is used to make the program run in its own thread, making the call to run non-blocking:

  pc = ProcessController()
  pc.run(['/bin/bash'], {
     'detached': True
  })
  pc.send('echo test')  # will print test to stdout
  pc.close()  # close stdin of subprogram, so that bash will read EOF

Don’t forget that you have to create a new instance a ProcessController everytime you want to execute a new subprogram

Please feel free to read the tests and code for a better understanding

ENJOY