python 运行CMD和shell命令

1. 方法1 os.system【切换目录等不适用】

#有状态码，无返回值
import os

os.system('taskkill /F /IM node.exe 2>nul')

2. 方法2 subprocess

# 功能最强
import subprocess
import shlex

def runCommand(cmd):
    output = subprocess.Popen(shlex.split(cmd), stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    # rst = output.stdout.read()  # .decode("UTF8").strip()
    rst = output.stdout.readlines()  # .decode("UTF8").strip()
    return rst

cmd = 'shutdown -s -t 90'
rst = runCommand(cmd)



# subprocess 文档
https://segmentfault.com/a/1190000020660715
#下面的用法是等价的
output = subprocess.Popen(['ping','1.1.1.1'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
stdout = output.stdout.read()
print(stdout.decode("gbk"))

child = subprocess.Popen(['ping','1.1.1.1'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
stdout, stderr = child.communicate()
print(stdout.decode("gbk"))

3. 方法3 ssh

bat = 'cmd.exe /c "if exist "' + dir + '" (echo y) else (echo n)"'
# print(bat.encode("gbk"))
# exit(000)
# 如果执行的命令中带有中文，需要将bat命令进行encode编码加密处理
stdin, stdout, stderr = ssh.exec_command(bat.encode("gbk"))
result = stdout.read().decode("gbk")
# print(result)
if result.strip() == 'y':
    print("\033[0;32m%s\033[0m" % "目录存在！")
else:
    print("\033[0;31m%s\033[0m" % "目录不存在！")
return


# 使用手册
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())    #指定当对方主机没有本机公钥的情况时应该怎么办，AutoAddPolicy表示自动在对方主机保存下本机的秘钥
ssh.connect('ip',22,'user','passwd')    #SSH端口默认22，可改
stdin,stdout,stderr = ssh.exec_command("命令内容")    #这三个得到的都是类文件对象
outmsg,errmsg = stdout.read(),stderr.read()    #读一次之后，stdout和stderr里就没有内容了，所以一定要用变量把它们带的信息给保存下来，否则read一次之后就没有了
if errmsg == "":
    print outmsg
if errmsg == b"":  # window 下
    print (outmsg.decode('gbk'))
ssh.close()

4. 方法4 commands

# 有状态码，返回值
import commands

status = commands.getstatus('cat /etc/passwd')
print(status)
output = commands.getoutput('cat /etc/passwd')
print(output)
(status, output) = commands.getstatusoutput('cat /etc/passwd')
print(status, output)

5. 方法5 os.popen

# 有状态码，返回值
import os
result = os.popen('cat /etc/passwd')
print(result.read())