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Editorial Team
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Asked: 2026-05-26T21:27:59+00:00

I am using paramiko for executing remote commands in python. I want to log

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I am using paramiko for executing remote commands in python. I want to log the complete remote commandline details to the log file.

e.g. Like using Expect in perl we can log the below commands with its output to a log file

samir@ssahoo-ub-in:~$ cat logfile.txt
samir@ssahoo-ub-in:~$ ls
Desktop  Documents  Downloads  examples.desktop  getskype-linux-beta-ubuntu-64  Music      Pictures  Public  Templates  Videos  VirtualBox VMs
samir@ssahoo-ub-in:~$ hostname
ssahoo-ub-in
samir@ssahoo-ub-in:~$ w
 09:11:12 up 10:26,  6 users,  load average: 0.05, 0.05, 0.06
USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU WHAT
samir    tty7     :0               22:45   10:26m 12:51   0.23s gnome-session     --session=classic-gnome
samir    pts/0    :0.0             22:46   10:24m 32.80s 14.34s gnome-terminal
samir    pts/1    :0.0             23:49    1:03m  0.57s  0.57s bash
samir    pts/2    :0.0             07:42    1:22m  0.48s  0.09s vim ../projects    /test/test_cases/common/TestHostname.py
samir    pts/3    :0.0             08:11    0.00s  0.57s  0.01s w
samir    pts/4    :0.0             08:24   46:08   0.21s  0.04s python
samir@ssahoo-ub-in:~$ who
samir    tty7         2011-11-10 22:45 (:0)
samir    pts/0        2011-11-10 22:46 (:0.0)
samir    pts/1        2011-11-10 23:49 (:0.0)
samir    pts/2        2011-11-11 07:42 (:0.0)
samir    pts/3        2011-11-11 08:11 (:0.0)
samir    pts/4        2011-11-11 08:24 (:0.0)
samir@ssahoo-ub-in:~$

I got the above issue resolved by using paramiko.invoke_shell()
e.g.

client = paramiko.SSHClient()
client.load_system_host_keys()
client.load_host_keys(os.path.expanduser('~/.ssh/known_hosts'))
client.set_missing_host_key_policy(AllowAllKeys())
client.connect(HOST, username=USER, password=PASSWORD)

channel = client.invoke_shell()
channel.send("ls -l\n")
while not channel.recv_ready():
    time.sleep(2)
results += channel.recv(1024)

But can someone help me in getting the stdout, stderr and return code(exit status) here ?

I tried with recv_stderr and recv_exit_status after invoking shell. But it doesn’t print anything when I tried to print stderr and exit status. Here is my piece of code:

import paramiko, time
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy()) 
ssh.connect('localhost', username='sam', password='mypassword')
channel = ssh.invoke_shell()
results = ''
results2 = ''
password = 'my_root_password'
try:
    channel.send("su -\n")
    while not channel.recv_ready():
        print "Waiting for root challenge..."
        time.sleep(2)
    results += channel.recv(1024)
    channel.send("%s\n" % password)
    while not channel.recv_ready():
        print "Authenticating..."
        time.sleep(2)
    results += channel.recv(1024)

    channel.send("ls file_doesnt_exist\n") # Here I am sending a wrong command to fail
    if channel.exit_status_ready():
        result3 = channel.recv_exit_status(1024)
    print "exit status is:", results3            # It doesnt return anything
    if channel.recv_stderr_ready():
        result2 = channel.recv_stderr(1024)
    print results2                                # Doesn't print error

except Exception, e:
    print e

I am getting some discrepancy in the return code below. May be I am not using in the proper way. Every-time I print the return code, it prints the same as the first one has returned. Do I need to reset the return code. I mean in the following example, I am getting the return code as 2 for both the commands. Now when I interchange both the commands, I mean replace ‘ls -al;exit\n’ with ‘ls -al file_not_exist;exit\n’ and vice versa, it prints return code 0. Each time it prints the same return code as the first one has returned.

channel = client.invoke_shell()
channel.send('ls -al file_not_exist;exit\n') #Sending to list a file which doesn't exist
time.sleep(3)
print "My 1st command exit status is: ",channel.exit_status_ready()
print "My 1st command return code is: ", channel.recv_exit_status()

channel.send('ls -al;exit\n')
time.sleep(3)
print "My 2nd command exit status is: ",channel.exit_status_ready()
print "My 2nd command return code is: ",channel.recv_exit_status()

I need to print the return code of each command. Could you please help me in how to get this issue resolved ?

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1 Answer

  1. Editorial Team

    Looks like from the paramiko.SSHClient docs, you can use the recv_ready and recv return the results of the shell/channel. For example, this worked for me:

    client = SSHClient()
lient.load_system_host_keys()
client.set_missing_host_key_policy(AllowAllKeys())
client.connect(HOST,username=USERNAME,password=PASSWORD)
channel = client.invoke_shell()
channel.send('ls\n')
while channel.recv_ready():
    channel.recv(1024)

channel.send('exit\n')
if channel.exit_status_ready():
    print channel.recv_exit_status()
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