Python子进程调用不能使用grep

Python子进程调用应该按命令原样运行,但是它在抱怨是否有管道.这是我的代码：#!/usr/bin/pythonimport sysimport subprocessimport timeservice_name= mysrvcstate =STOPPEDmycmd =sc query + service_n...

Python子进程调用应该按命令原样运行,但是它在抱怨是否有管道.这是我的代码：

#!/usr/bin/python

import sys
import subprocess
import time
service_name= "mysrvc"
state ="STOPPED"
mycmd ="sc query " + service_name + " " + "|" + " findstr" + " " + state 
print(mycmd)
if subprocess.call(mycmd)==0:
  print("Service stopped successfully")

我得到的错误是：

ERROR: Invalid Option; Would you like to see help for the QUERY and QUERYEX commands? [ y | n ]:

如果我将命令更改为

mycmd = "sc query " + service_name 

我能够成功运行脚本.只是管道及其后的参数是一个问题.如果我运行sc查询mysvrc | findstr直接在命令行上停止,可以正常工作.

我该如何工作？请注意,我使用jython2.7运行此python脚本.我无法成功使用win32serviceutil,因为它找不到模块win32serviceutil.

解决方法:

如前所述,为subprocess can’t handle single str inputs and shell metacharacters like | unless shell=True.但是在这种情况下,您实际上确实不需要管道.您可以让Python进行过滤,避免管道完全找到str：

# sc query command only, as list which gets better safety/performance
mycmd = ["sc", "query", service_name]

# Open command to run asynchronously, capturing output
proc = subprocess.Popen(mycmd, stdout=subprocess.PIPE)

# Wait for process to complete while slurping output
stdout, _ = proc.communicate()

# Check if expected output was seen and process exited successfully
if state in stdout and proc.returncode == 0:
    print("Service stopped successfully")