Chilkat2-Python

Run a Command on an SSH Session Channel

Demonstrates the Chilkat Ssh.SendReqExec method, which requests execution of a command on a session channel. The first argument is the channel number and the second is the command line. This example runs a command, reads the output until the channel closes, and prints it.

Background: exec is the workhorse for automation: run one command, collect its output, and finish — no interactive shell needed. Note carefully that a true return means the request was accepted, not that the command succeeded. To learn the command's outcome, read its output and check the channel exit status.

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import sys
import chilkat2

success = False

# Demonstrates the Ssh.SendReqExec method, which requests execution of a command on a session
# channel.  The 1st argument is the channel number and the 2nd is the command line.

ssh = chilkat2.Ssh()

sshPort = 22
success = ssh.Connect("ssh.example.com",sshPort)
if (success == False):
    print(ssh.LastErrorText)
    sys.exit()

# Normally you would not hard-code the password in source.  You should instead obtain it
# from an interactive prompt, environment variable, or a secrets vault.
password = "mySshPassword"

success = ssh.AuthenticatePw("mySshLogin",password)
if (success == False):
    print(ssh.LastErrorText)
    sys.exit()

# Open a session channel.  A negative return value indicates failure.
channelNum = ssh.OpenSessionChannel()
if (channelNum < 0):
    print(ssh.LastErrorText)
    sys.exit()

# Request execution of a command.  A True return means the server accepted the request; it
# does not mean the command itself succeeded.
success = ssh.SendReqExec(channelNum,"ls -l /tmp")
if (success == False):
    print(ssh.LastErrorText)
    sys.exit()

# IMPORTANT: Set a read timeout.  ReadTimeoutMs defaults to 0, which means no limit -- without
# it, this call waits forever if the server never sends channel close.
ssh.ReadTimeoutMs = 15000

# Read the command output until the server closes the channel.
success = ssh.ChannelReceiveToClose(channelNum)
if (success == False):
    print(ssh.LastErrorText)
    sys.exit()

output = ssh.GetReceivedText(channelNum,"utf-8")
if (ssh.LastMethodSuccess == False):
    print(ssh.LastErrorText)
    sys.exit()

print(output)

ssh.Disconnect()