subshell.py

import subprocess
import threading
from queue import Empty, Queue

import colorama

colorama.init()


class Shell:
  def __init__(self):
    self.proc = subprocess.Popen(["/bin/sh"], stdin=subprocess.PIPE,stdout=subprocess.PIPE,stderr=subprocess.PIPE,bufsize=1,encoding='utf-8')
    self.proc_msg_queue = Queue()
    self.output_conn = None
    self.log = False
    threading.Thread(target=self.read_stdout, daemon=True).start()
    threading.Thread(target=self.read_stderr, daemon=True).start()
  def relay(self, msg):
    try:
      if self.output_conn is not None:
        self.output_conn.send((msg + "\n").encode())
    except Exception:
      pass
  def read_stdout(self):
    while True:
      line = self.proc.stdout.readline()
      if not line:
        break
      self.proc_msg_queue.put(("stdout", line))
      if "%*&" not in line:
        if self.log:
          print(line.strip())
        self.relay(line.strip())

  def read_stderr(self):
    while True:
      line = self.proc.stderr.readline()
      if not line:
        break
      self.proc_msg_queue.put(("stderr", line))
      if self.log:
        print(line.strip())
      self.relay(line.strip())

  def run_cmd(self, cmd):
    if self.log:
      print(colorama.Fore.GREEN + f"> {cmd}" + colorama.Fore.RESET)
    self.relay(colorama.Fore.GREEN + f"> {cmd}" + colorama.Fore.RESET)
    self.proc.stdin.write(f'{cmd} ; echo "%*&$?"\n')
    self.proc.stdin.flush()
    output = ""
    error = ""
    code = 0
    while True:
      try:
        type, line = self.proc_msg_queue.get_nowait()
        if type == "stdout" and "%*&" in line:
          code = int(line[(line.find("%*&") + 3):])
          break
        if type == "stdout":
          output += line + "\n"
        if type == "stderr":
          error += line + "\n"
      except Empty:
        pass
    if (code != 0):
      raise Exception(code, error)
    return (output, error, code)
  def close(self):
    self.output_conn = False
    self.log = False
    self.proc.stderr.close()
    self.proc.stdin.close()
    self.proc.stdout.close()
    self.proc.terminate()