如何使用Paramiko獲得SSH返回碼？

Question

client = paramiko.SSHClient() 
stdin, stdout, stderr = client.exec_command(command) 

有什麼辦法可以得到命令的返回碼嗎？

很難解析所有的標準輸出/標準錯誤，並知道命令是否成功完成。

Answer 1

SSHClient是Paramiko中較低級功能的簡單包裝類。 API documentation在Channel類上列出了一個recv_exit_status()方法。

一個非常簡單的演示腳本：

$ cat sshtest.py 
import paramiko 
import getpass 

pw = getpass.getpass() 

client = paramiko.SSHClient() 
client.set_missing_host_key_policy(paramiko.WarningPolicy()) 
client.connect('127.0.0.1', password=pw) 

while True: 
    cmd = raw_input("Command to run: ") 
    if cmd == "": 
     break 
    chan = client.get_transport().open_session() 
    print "running '%s'" % cmd 
    chan.exec_command(cmd) 
    print "exit status: %s" % chan.recv_exit_status() 

client.close() 

$ python sshtest.py 
Password: 
Command to run: true 
running 'true' 
exit status: 0 
Command to run: false 
running 'false' 
exit status: 1 
Command to run: 
$ 

Answer 2

很多簡單的例子，不涉及直接調用通道類：

import paramiko 

client = paramiko.SSHClient() 
client.set_missing_host_key_policy(paramiko.AutoAddPolicy()) 
client.connect('blahblah.com') 

stdin, stdout, stderr = client.exec_command("uptime") 
print stdout.channel.recv_exit_status() # status is 0 

stdin, stdout, stderr = client.exec_command("oauwhduawhd") 
print stdout.channel.recv_exit_status() # status is 127 

Answer 3

感謝JanC，我加了一些修改的例子，在Python3中測試，它對我來說真的很有用。

import paramiko 
import getpass 

pw = getpass.getpass() 

client = paramiko.SSHClient() 
client.set_missing_host_key_policy(paramiko.WarningPolicy()) 
#client.set_missing_host_key_policy(paramiko.AutoAddPolicy()) 

def start(): 
    try : 
     client.connect('127.0.0.1', port=22, username='ubuntu', password=pw) 
     return True 
    except Exception as e: 
     #client.close() 
     print(e) 
     return False 

while start(): 
    key = True 
    cmd = input("Command to run: ") 
    if cmd == "": 
     break 
    chan = client.get_transport().open_session() 
    print("running '%s'" % cmd) 
    chan.exec_command(cmd) 
    while key: 
     if chan.recv_ready(): 
      print("recv:\n%s" % chan.recv(4096).decode('ascii')) 
     if chan.recv_stderr_ready(): 
      print("error:\n%s" % chan.recv_stderr(4096).decode('ascii')) 
     if chan.exit_status_ready(): 
      print("exit status: %s" % chan.recv_exit_status()) 
      key = False 
      client.close() 
client.close()