process.py

import os
import signal

class Process(object):
	"""Represents a process"""

	def __init__(self, pid):
		"""Make a new Process object"""
		self.proc = "/proc/%d" % pid
		f = open(os.path.join(self.proc, "stat"))
		pid,command,state,parent_pid = f.read().strip().split()[:4]
		f.close()
		command = command[1:-1]
		self.pid = int(pid)
		self.command = command
		self.state = state
		try:
			self.parent_pid = int(parent_pid)
		except:
			self.parent_pid = int(0)
		self.parent = None
		self.children = []

	def kill(self, sig = signal.SIGTERM):
		"""Kill this process with SIGTERM by default"""
		os.kill(self.pid, sig)

	def __repr__(self):
		return "%r" % self.pid

	def getcwd(self):
		"""Read the current directory of this process or None for can't"""
		try:
			return os.readlink(os.path.join(self.proc, "cwd"))
		except OSError:
			return None

class ProcessList(object):
	"""Represents a list of processes"""

	def __init__(self):
		"""Read /proc and fill up the process lists"""
		self.by_pid = {}
		self.by_command = {}
		for f in os.listdir("/proc"):
			try:
				if f.isdigit():
					process = Process(int(f))
					self.by_pid[process.pid] = process
					self.by_command.setdefault(process.command, []).append(process)
			except IOError:
				pass
		for process in self.by_pid.values():
			try:
				parent = self.by_pid[process.parent_pid]
				#print "child",process
				#print "parent",parent
				parent.children.append(process)
				process.parent = parent
			except KeyError:
				pass

	def named(self, name):
		"""Returns a list of processes with the given name"""
		return self.by_command.get(name, [])