12.7python笔记(3.5-3.8)

3.5 rc脚本(类的定义与脚本的结构)
用python写一个 启动脚本

#!/usr/bin/python

import sys
import os
from subprocess import Popen, PIPE

class Process(object):
'''memcached rc script'''
def init(self,name,program,args,workdir):
self.name = name
self.program = program
self.args = args
self.workdir = workdir

def _pidFile(self):
'''/var/tmp/memcached/memcached.pid'''
return os.path.join(self.workdir, "%s.pid" % self.name)
def _writhPid(self):
if self.pid:
with open(self._pidFile(),'w') as fd:
fd.write(str(self.pid))

def _init(self):
'''/var/tmp/memcached'''
if not os.path.exists(self.workdir):
os.mkdir(self.workdir)
os.chdir(self.workdir)

def start(self):
self._init()
cmd = self.program  + ' ' + self.args
p = Popen(cmd, stdout=PIPE, shell=True)
self.pid = p.pid
self._writhPid()
print "%s start Sucessful" % self.name

def _getPid(self):
p = Popen(['pidof',self.name],stdout=PIPE)
pid = p.stdout.read().strip()
return pid

def stop(self):
pid=self._getPid()
if pid:
os.kill(int(pid),15)
if os.path.exists(self._pidFile()):
os.remove(self._pidFile())
print "%s is stopped" % self.name

def restart(self):
self.stop()
self.start()

def status(self):
pid=self._getPid()
if pid:
print "%s is already running" % self.name
else:
print "%s is not running" % self.name

def help(self):
print "Usage : %s {start|stop|status|restart}" % __file__

def main():
name = 'memcached'
prog = '/usr/bin/memcached'
args = '-u nobody -p 11211 -c 1024 -m 64'
wd = '/var/tmp/memcached'
pm = Process(name=name,program=prog,args=args,workdir = wd)

try:
cmd = sys.argv[1]
except IndexError, e:
print "Option error"
sys.exit()
if cmd == 'start':
pm.start()
elif cmd == 'stop':
pm.stop()
elif cmd == 'restart':
pm.restart()
elif cmd == 'status':
pm.status()
else:
pm.help()

if name == 'main':
main()