Reading output of Top command using Paramiko
Solution 1
as Jason S pointed out
stdin, stdout, stderr = ssh.exec_command("top -b -n1")
print stdout.read()
works just fine.
Solution 2
top
normally uses curses for display rather than just printing. Try the -b
for batch option along with the -n 1
you have (top options vary by platform, check the manpage). And in the future, try isolating the problem more - if you were to invoke top
via ssh
on the command line without your script you would still have an issue.
N Deepak Prasath
Updated on June 07, 2022Comments
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N Deepak Prasath almost 2 years
I am writing a script in Python for login to ssh and read the output of commands just executed. I am using paramiko package for this. I am trying to execute command "top" and get its output printed on the console. However, I am not able to do this. Please find the snippet:
import sys import time import select import paramiko host = 'localhost' i = 1 # # Try to connect to the host. # Retry a few times if it fails. # while True: print 'Trying to connect to %s (%i/30)' % (host, i) try: ssh = paramiko.SSHClient() ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy()) ssh.connect(host, port=22, username='dummy', password='dummy') print "Connected to %s" % host break except paramiko.AuthenticationException: print "Authentication failed when connecting to %s" % host sys.exit(1) except: print "Could not SSH to %s, waiting for it to start" % host i += 1 time.sleep(2) # If we could not connect within time limit if i == 30: print "Could not connect to %s. Giving up" % host sys.exit(1) # Send the command (non-blocking) stdin, stdout, stderr = ssh.exec_command("uname") # Wait for the command to terminate while not stdout.channel.exit_status_ready(): # Only print data if there is data to read in the channel if stdout.channel.recv_ready(): rl, wl, xl = select.select([stdout.channel], [], [], 0.0) if len(rl) > 0: # Print data from stdout print '-------------------------------' print stdout.channel.recv(1024) print '-------------------------------' # Send the command (non-blocking) stdin, stdout, stderr = ssh.exec_command("top -n 1") # Wait for the command to terminate while not stdout.channel.exit_status_ready(): # Only print data if there is data to read in the channel if stdout.channel.recv_ready(): rl, wl, xl = select.select([stdout.channel], [], [], 0.0) if len(rl) > 0: # Print data from stdout print '-------------------------------' print stdout.channel.recv(1024) print '-------------------------------' # Send the command (non-blocking) stdin, stdout, stderr = ssh.exec_command("uname") # Wait for the command to terminate while not stdout.channel.exit_status_ready(): # Only print data if there is data to read in the channel if stdout.channel.recv_ready(): rl, wl, xl = select.select([stdout.channel], [], [], 0.0) if len(rl) > 0: # Print data from stdout print '-------------------------------' print stdout.channel.recv(1024) print '-------------------------------' # # Disconnect from the host # print "Command done, closing SSH connection" ssh.close()
Output: Trying to connect to localhost (1/30)
Connected to localhost
Linux
-------------------------------
Linux
Command done, closing SSH connection
I am not sure, where I am doing wrong. I am able to get output of other linux commands though. But not sure, why top command's output is not getting printed.
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Jason S over 9 yearsYes I did. Does your host's
top
support the-b
option?