最近写了个脚本，需要执行第三方程序，并根据程序输出判断执行情况，当程序执行时间过长时kill该进程。因此选用了subprocess模块。

process = subprocess.Popen(self.cmd,stdin = subprocess.PIPE, stdout = subprocess.PIPE, stderr = subprocess.PIPE, shell=True ,close_fds=True)

1. 在linux下，不加参数 shell=True 会报错

2. 当没有参数 close_fds=True 时，打开的标准输入、标准输出、标准错误不会被关闭，当打开的文件数量超过最大值时会产生“OSError: [Errno 24] Too many open files”异常。（但也有人说不起作用需要自己关闭标准输入、标准输出、标准错误，但是暂时没有发现这种情况）

3. 当不使用process.terminate()终止进程后，再使用process.kill()，会导致进程kill失败

4. 开始使用process.stdout.readline()在子线程中循环读取管道内容，虽然中间有sleep但也十分消耗资源。（后改为进程结束时使用process.stdout.read()读取全部内容）

记录下来防止时间长了，忘记了。不对的地方还请指正。。。

#coding=utf-8
'''
Created on 2015-8-13@author: xhw@explain: pass(添加返回索引输出内容：给合并索引模块使用，判断是否合并成功)
'''
import time
import subprocess
import threading
import common.logger as log 
from common.traceback_error import get_err_msg
from common.MailHandler import SendMail
import sys,os,shutil
system = sys.platform
Maxtime = 999999
reload(sys)
sys.setdefaultencoding('utf-8')class CmdServer:def __init__(self,cmd,timeout,taskname):''' @cmd:命令字符串@timeout:任务超时时间(进程运行超过该时间，kill该进程)@taskname:任务名称（根据该任务名称记录命令输出信息）'''print cmd,timeout,taskname,time.strftime("%Y-%m-%d %H:%M:%S")self.cmd = cmdif timeout:self.timeout = int(timeout)else:self.timeout = Maxtimeself.path = os.path.join(os.path.dirname(__file__),'cmd_stdout')self.stdoutfile = os.path.join(self.path,taskname + '.txt')self.renamefile = os.path.join(self.path,taskname + '1.txt')def run(self):self.writeStdout(self.cmd+'\n')try:#在windows下运行非shell命令时，使用shell=True，不能使子进程结束（linux下没有测试）process = subprocess.Popen(self.cmd,stdin = subprocess.PIPE, stdout = subprocess.PIPE, stderr = subprocess.PIPE, shell=True ,close_fds=True)num = 0while process.poll() == None:if num >= self.timeout:self.writeStdout(u"任务超时！\n")try:process.terminate()stdout = self.readStdout(process)process.kill()process.wait()self.writeStdout(u"任务kill！\n")return False,"Task running timeout!"+str(stdout)except:errmsg = get_err_msg()log.CmdRun_Logger.error(errmsg)self.writeStdout(u"任务kill失败！\n")SendMail(subject = 'command_worker', content = errmsg)return False,"Task running timeout,Kill failure"+str(stdout)time.sleep(1)num+= 1if process.poll() is not None:self.writeStdout(u"任务结束！\n")stdout = self.readStdout(process)process.wait()return True,stdoutexcept:errmsg = get_err_msg()log.CmdRun_Logger.error(errmsg)SendMail(subject = 'command_worker', content = errmsg)return False,errmsgdef readStdout(self,process):''' 读取执行命令进程输出的内容，并写入日志文件'''stdout = ""try:stdout = process.stdout.read()if stdout:if 'win' in system:stdout = stdout.decode('gbk','ignore').encode('utf-8') self.writeStdout(stdout)except:errmsg = get_err_msg()log.CmdRun_Logger.error(errmsg)SendMail(subject = 'command_worker', content = errmsg)return stdoutdef writeStdout(self,stdout):''' 记录命令输出'''try:stdout = stdout.strip()with open(self.stdoutfile, 'a+') as f:f.write(stdout+'\r\n')except:errmsg = get_err_msg()log.CmdRun_Logger.error(errmsg)SendMail(subject = 'command_worker', content = errmsg)self.checklogfile()def checklogfile(self):''' 这里使用日志模块并不清楚会有那些任务,所以没有使用配置文件,但不使用配置文件,会在日志文件设置上出现问题,在这里自己替换超过大小到日志文件(默认两个日志文件,每个10M)'''if not os.path.exists(self.stdoutfile):returnif os.path.getsize(self.stdoutfile) > 1024*1024*10:try:print self.stdoutfile, self.renamefile#os.rename(self.stdoutfile, self.renamefile)#会提示WindowsError: [Error 32],不清楚是不是OS模块操作文件没有关闭引起的shutil.copyfile(self.stdoutfile, self.renamefile)with open(self.stdoutfile,'w') as f:f.write(time.strftime('%Y-%m-%d %H:%M:%S'+'\r\n'))except:errmsg = get_err_msg()log.CmdRun_Logger.error(errmsg)SendMail(subject = 'command_worker', content = errmsg)if __name__ == '__main__':A = CmdServer(r'python E:\work\sphinx_task\test_task\test3.py',50,'test3')A.run()