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     cmd = "LC_ALL=C %s" % cmd
  29     logger.log("+ %s" % cmd)
  30     (code, sout, serr) = execute(cmd)
  31     o = ""
  32     if code != 0:
  33         e = serr.read().strip()
  34         if e: logger.err(e)
  35     else:
  36         o = sout.read()
  37         logger.log(o)
  38     return o
  39
  40 def kill_by_name(proc):
  41     cmd = "%s %s" % (config.pgrep, os.path.basename(proc))
  42     out = run(cmd).strip()
  43     deadline = time.time()+0.3
  44     while out and time.time() < deadline:
  45         pids = string.split(out, "\n")
  46         for p in pids:
  47             pid = -1
  48             try: pid = int(p)
  49             except ValueError:
  50                 logger.err("Cast of pid int('%s') for process '%s' failed" % (p, proc))
  51                 return
  52             try:
  53                 os.kill(pid, signal.SIGINT)
  54                 os.kill(pid, signal.SIGTERM)
  55                 os.kill(pid, signal.SIGKILL)
  56             except OSError:
  57                 logger.err("Failed to kill process '%s' pid %d" % (proc, pid))
  58                 return
  59         out = run(cmd).strip()
  60
  61 def kill_previous_instances():
  62     pids = system.getfile(config.pidfile).strip().split("\n")
  63     if not [x for x in pids if x != ""]: return
  64
  65     # truncate pidfile
  66     try: f = open(config.pidfile, 'w'); f.close()
  67     except IOError:
  68         logger.err("Could not truncate pidfile %s" % config.pidfile, log=False)
  69
  70     for pid in pids:
  71         pid = int(pid)
  72         out = run("%s %s" % (config.ps, pid))
  73         active = regex.find1("(%s)" % config.program_name, out)
  74         if out and active:
  75             os.kill(pid, signal.SIGINT)
  76             os.kill(pid, signal.SIGTERM)
  77             os.kill(pid, signal.SIGKILL)
  78
  79 def write_pid():
  80     try:
  81         f = open(config.pidfile, 'a')
  82         f.write("%s\n" % os.getpid())
  83         f.close()
  84     except IOError:
  85         logger.err("Could not write to pidfile %s" % config.pidfile, log=False)
  86
  87 def daemonize():
  88     # do unix double fork
  89     try:
  90         pid = os.fork()
  91         if pid > 0: sys.exit(0)
  92     except OSError:
  93         logger.err("Failed to daemonize", log=False)
  94         sys.exit(1)
  95
  96     os.chdir("/")
  97     os.setsid()
  98     os.umask(0)
  99     child_in =open('/dev/null','r')
 100     child_out=open('/dev/null','w')
 101     os.dup2(child_in.fileno(), sys.stdin.fileno())
 102     os.dup2(child_out.fileno(), sys.stdout.fileno())
 103     os.dup2(child_out.fileno(), sys.stderr.fileno())
 104
 105     try:
 106         pid = os.fork()
 107         if pid > 0: sys.exit(0)
 108     except OSError:
 109         logger.err("Failed to daemonize", log=False)
 110         sys.exit(1)