guard_wrapper

#!/usr/bin/env python

import sys
import os
import subprocess
import threading


class GuardWrapper:
    def __init__(self):
        self.running = False
        self.proc = None
        self.stdout_thread = None
        self.stderr_thread = None
        self.log = open('/tmp/guard_wrapper.log', 'w')

    def run_cmd(self, cmd_array):
        self.proc = subprocess.Popen(cmd_array, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        self.running = True
        if self.proc.stdout:
            self.stdout_thread = threading.Thread(target=self.read_stdout, args=())
            self.stdout_thread.start()
        if self.proc.stderr:
            self.stderr_thread = threading.Thread(target=self.read_stderr, args=())
            self.stderr_thread.start()
        while True:
            self.log.write("read stdin iteration\n")
            self.log.flush()
            data = sys.stdin.readline()
            if data != "":
                self.log.write("Received: " + data + "\n")
                self.log.flush()
                if data == "e\n":
                    self.proc.stdin.write(data)
                    self.proc.stdin.flush()
                    break
                else:
                    self.proc.stdin.write(data)
                    self.proc.stdin.flush()
            else:
                self.log.write("got empty string, :-(\n")
                self.log.flush()
                self.proc.stdin.write("e\n")
                self.proc.stdin.flush()
                self.proc.stdin.close()
                break
        self.stdout_thread.join()
        self.stderr_thread.join()

    def read_stdout(self):
        while True:
            data = os.read(self.proc.stdout.fileno(), 2 ** 15)
            if data != "":
                sys.stdout.write(data)
                sys.stdout.flush()
            else:
                self.proc.stdout.close()
                self.running = False
                break

    def read_stderr(self):
        while True:
            data = os.read(self.proc.stderr.fileno(), 2 ** 15)
            if data != "":
                sys.stderr.write(data)
                sys.stderr.flush()
            else:
                self.proc.stderr.close()
                self.running = False
                break


wrap = GuardWrapper()
wrap.run_cmd(sys.argv[1:])