a process utility for logging and restarting apps.

pMonitor.py

import subprocess
import select
import time
import sys

#no-nonsense python utility for app testing
#pythons subprocess class is really weird...
class pMonitor:
  pM_proc = False
  pM_path = False
  pM_log  = False
  pM_rept = False

  def __init__(self, path, persist, log ):
    self.pM_path = path
    self.pM_log  = log
    self.pM_rept = persist
    if log:
      print '[] creating logfile ' + log
      self.pM_log = open(log,'w')


  def start(self):
    self.pM_proc = subprocess.Popen(self.pM_path, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    stdout = []
    stderr = []

    while True:
      Queu = [self.pM_proc.stdout.fileno(),self.pM_proc.stderr.fileno()]
      Next = select.select(Queu, [], [])

      for it in Next[0]:
        if it == self.pM_proc.stdout.fileno():
          line =  self.pM_proc.stdout.readline()
          if self.pM_log:
            self.pM_log.write(time.strftime("%I_%M") + ':' + line )
          sys.stdout.write( 'out: ' + line )
          stdout.append(line)
        if it == self.pM_proc.stderr.fileno():
          line = self.pM_proc.stderr.readline()
          if self.pM_log:
            self.pM_log.write(time.strftime("%I_%M") + ':' + line )
          sys.stdout.write( 'err: ' + line )
          stdout.append(line)

      if self.pM_proc.poll() != None:
        break

    print self.pM_path +  ' exited '
    print '[] persistence %r' % self.pM_rept
    if self.pM_rept:
      print '[] restarting...'
      self.start()



  def end(self):
    self.pM_proc.kill()


def start_example():
  Log  = 'LOG_' + time.strftime("%I_%M_%S")
  proc = pMonitor( './a.out', True, Log )
  try:
    proc.start()
  except KeyboardInterrupt:
    print '[] process over'
    proc.end()


start_example()