Printing real-time SSH output using Python 3.x

Question

I have a script that SSH connects from Windows7 to a remote ubuntu server and executes a command. The script returns Ubuntu command output to the Windows cmd window in one go after the command has executed and finished. I am just wondering if there is anyway to return real-time SSH output in my script below, or do I always have to wait for the command to finish before seeing the output.

Here's my working code:

import paramiko

ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
host = '9.10.11.12'
port, user, password = 22, 'usr', 'pass'
ssh.connect(host, port,  user, password)
stdin,stdout,stderr = ssh.exec_command("cd /opt/app && ./app-tool some_command")

for line in stdout.readlines():
    print(line)

ssh.close()

Alternatively, if this is not possible with SSH how would I introduce a spinning cursor icon into the above script? Thanks.

MikG · Accepted Answer · 2016-06-17 07:56:34Z

5

Figured it out in the end, I used 'iter' method in the following line:

for line in iter(stdout.readline,""): 
    print(line)

answered Jun 17, 2016 at 7:56

MikG

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Comments

gaganso · Accepted Answer · 2016-06-16 14:32:13Z

0

The output of your command seems to less than the default buffer size because of which it is getting flushed once the command completes.

By default the bufsize is -1 which means that the system default buffer size is used. If bufsize is set to 1 then it is line buffered.

Use

ssh.exec_command("<cmd>",bufsize=1)

answered Jun 16, 2016 at 14:32

gaganso

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3 Comments

MikG Over a year ago

Hi SilentMonk, I tried your suggestion but I get the same outcome where the output is dumped at the end of execution.

gaganso Over a year ago

oh, what about bufsize=0? This means no buffering. Also, what is the size of the output from your command?

MikG Over a year ago

Hi SilentMonk, thanks for your help. I had a play around and in the end I used the code >>> for line in iter(stdout.readline,""): print(line)

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