python中執行shell命令行read結果

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python執行shell命令
1 os.system

能夠返回運行shell命令狀態，同時會在終端輸出運行結果

例如 ipython中運行以下命令，返回運行狀態status

os.system('python -V')
os.system('tree')

 

2 os.popen()

能夠返回運行結果

import os

r = os.popen('python -V').read()
print(type(r))
print(r)

　　

或者

In [20]: output = os.popen('cat /proc/cpuinfo')

In [21]: lineLen = []

In [22]: for line in output.readlines():
    lineLen.append(len(line))
   ....:     

In [23]: line
line     lineLen  

In [23]: lineLen
Out[23]: 
[14,
 25,
...

　　

3 commands.getstatusoutput('cat /proc/cpuinfo')

如何同時返回結果和運行狀態，commands模塊:

import commands
(status, output) = commands.getstatusoutput('cat /proc/cpuinfo')

In [25]: status
Out[25]: 0

In [26]: len(output)
Out[26]: 3859

　　

4 subprocess.Popen(["ls","-l"], stdout=subprocess.PIPE)

使用模塊subprocess

一般項目中常用方法爲subporcess.Popen, 咱們能夠在Popen()創建子進程的時候改變標準輸入、標準輸出和標準錯誤，並能夠利用subprocess.PIPE將多個子進程的輸入和輸出鏈接在一塊兒，構成管道(pipe):

　　

import subprocess
child1 = subprocess.Popen("tree",shell=True, stdout=subprocess.PIPE)
out = child1.stdout.read()
print(out.decode('gbk'))

　　

import subprocess
child1 = subprocess.Popen("tree /F".split(),shell=True, stdout=subprocess.PIPE)
out = child1.stdout.read()
print(out.decode('gbk'))

　　

import subprocess
child1 = subprocess.Popen(['tree','/F'].split(),shell=True, stdout=subprocess.PIPE)
out = child1.stdout.read()
print(out.decode('gbk'))

　　

退出進程

size_str = os.popen('adb shell wm size').read()
if not size_str:
　　print('請安裝 ADB 及驅動並配置環境變量')
　　sys.exit()

　　

封裝好的函數：Python執行shell命令

from subprocess import Popen, PIPE


def run_cmd(cmd):
    # Popen call wrapper.return (code, stdout, stderr)
    child = Popen(cmd, stdin=PIPE, stdout=PIPE, stderr=PIPE, shell=True)
    out, err = child.communicate()
    ret = child.wait()
    return (ret, out, err)

if __name__ == '__main__':
    r=run_cmd("dir")

    print(r[0])
    print(r[1].decode("gbk"))
    print(r[2])