procs.py

   1 # Author: Martin Matusiak <numerodix@gmail.com>
   2 # Licensed under the GNU Public License, version 3.
   3
   4 import popen2
   5 import os
   6 import signal
   7 import string
   8 import sys
   9 import time
  10
  11 from conf import config
  12 from output import logger
  13 import regex
  14 import system
  15
  16
  17 # Manage processes
  18
  19 def execute(cmd):
  20     process = popen2.Popen3(cmd, True)
  21     sout = process.fromchild
  22     serr = process.childerr
  23     code = process.wait()
  24     return (code, sout, serr)
  25
  26 def run(cmd):
  27     #logger.display("+ " + cmd, log=False)
  28     logger.log("+ %s" % cmd)
  29     (code, sout, serr) = execute(cmd)
  30     o = ""
  31     if code != 0:
  32         e = serr.read().strip()
  33         if e: logger.err(e)
  34     else:
  35         o = sout.read()
  36         logger.log(o)
  37     return o
  38
  39 def kill_by_name(proc):
  40     cmd = "%s %s" % (config.pgrep, os.path.basename(proc))
  41     out = run(cmd).strip()
  42     deadline = time.time()+0.3
  43     while out and time.time() < deadline:
  44         pids = string.split(out, "\n")
  45         for p in pids:
  46             pid = -1
  47             try: pid = int(p)
  48             except ValueError:
  49                 logger.err("Cast of pid int('%s') for process '%s' failed" % (p, proc))
  50                 return
  51             try:
  52                 os.kill(pid, signal.SIGINT)
  53                 os.kill(pid, signal.SIGTERM)
  54                 os.kill(pid, signal.SIGKILL)
  55             except OSError:
  56                 logger.err("Failed to kill process '%s' pid %d" % (proc, pid))
  57                 return
  58         out = run(cmd).strip()
  59
  60 def kill_previous_instances():
  61     pids = system.getfile(config.pidfile).strip().split("\n")
  62     if not [x for x in pids if x != ""]: return
  63
  64     # truncate pidfile
  65     try: f = open(config.pidfile, 'w'); f.close()
  66     except IOError:
  67         logger.err("Could not truncate pidfile %s" % config.pidfile, log=False)
  68
  69     for pid in pids:
  70         pid = int(pid)
  71         out = run("%s %s" % (config.ps, pid))
  72         active = regex.find1("(%s)" % config.program_name, out)
  73         if out and active:
  74             os.kill(pid, signal.SIGINT)
  75             os.kill(pid, signal.SIGTERM)
  76             os.kill(pid, signal.SIGKILL)
  77
  78 def write_pid():
  79     try:
  80         f = open(config.pidfile, 'a')
  81         f.write("%s\n" % os.getpid())
  82         f.close()
  83     except IOError:
  84         logger.err("Could not write to pidfile %s" % config.pidfile, log=False)
  85
  86 def daemonize():
  87     # do unix double fork
  88     try:
  89         pid = os.fork()
  90         if pid > 0: sys.exit(0)
  91     except OSError:
  92         logger.err("Failed to daemonize", log=False)
  93         sys.exit(1)
  94
  95     os.chdir("/")
  96     os.setsid()
  97     os.umask(0)
  98     child_in =open('/dev/null','r')
  99     child_out=open('/dev/null','w')
 100     os.dup2(child_in.fileno(), sys.stdin.fileno())
 101     os.dup2(child_out.fileno(), sys.stdout.fileno())
 102     os.dup2(child_out.fileno(), sys.stderr.fileno())
 103
 104     try:
 105         pid = os.fork()
 106         if pid > 0: sys.exit(0)
 107     except OSError:
 108         logger.err("Failed to daemonize", log=False)
 109         sys.exit(1)