CkPython

Multiple SendReqExec on Same Connection

Shows how to execute a series of commands on an SSH server and retrieve each command's output (using SendReqExec). Each call to SendReqExec requires its own logical channel. This is not a separate SSH connection -- it's simply a new session channel on the existing SSH connection. CkPython

import sys
import chilkat

success = False

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

ssh = chilkat.CkSsh()

# Hostname may be an IP address or domain:
hostname = "172.16.16.46"
port = 22

success = ssh.Connect(hostname,port)
if (success == False):
    print(ssh.lastErrorText())
    sys.exit()

# If receiving output from a command stalls for more than 5 seconds, then stop waiting.
ssh.put_IdleTimeoutMs(5000)

# Authenticate using login/password:
success = ssh.AuthenticatePw("myLogin","myPassword")
if (success == False):
    print(ssh.lastErrorText())
    sys.exit()

# Open a session channel.  (It is possible to have multiple
# session channels open simultaneously.)
channelNum = ssh.OpenSessionChannel()
if (channelNum < 0):
    print(ssh.lastErrorText())
    sys.exit()

# Request a directory listing on the remote server:
# If your server is Linux/UNIX, change the string from "dir" to "ls"
# Note: Some SSH servers require a CRLF instead of a bare-LF
cmd = "ls -al\n"
success = ssh.SendReqExec(channelNum,cmd)
if (success == False):
    print(ssh.lastErrorText())
    sys.exit()

# Read whatever output may already be available on the
# SSH connection.  ChannelReadAndPoll returns the number of bytes
# that are available in the channel's internal buffer that
# are ready to be "picked up" by calling GetReceivedText
# or GetReceivedData.
# A return value of -1 indicates failure.
# A return value of -2 indicates a failure via timeout.

# The ChannelReadAndPoll method waits
# for data to arrive on the connection usingi the IdleTimeoutMs
# property setting.  Once the first data arrives, it continues
# reading but instead uses the pollTimeoutMs passed in the 2nd argument:
# A return value of -2 indicates a timeout where no data is received.
pollTimeoutMs = 2000
n = ssh.ChannelReadAndPoll(channelNum,pollTimeoutMs)
if (n < 0):
    print(ssh.lastErrorText())
    sys.exit()

# Close the channel:
success = ssh.ChannelSendClose(channelNum)
if (success == False):
    print(ssh.lastErrorText())
    sys.exit()

# Perhaps we did not receive all of the commands output.
# To make sure,  call ChannelReceiveToClose to accumulate any remaining
# output until the server's corresponding "channel close" is received.
success = ssh.ChannelReceiveToClose(channelNum)
if (success == False):
    print(ssh.lastErrorText())
    sys.exit()

# Get the accumulated output of the command:

cmdOutput = ssh.getReceivedText(channelNum,"ansi")
if (ssh.get_LastMethodSuccess() == False):
    print(ssh.lastErrorText())
    sys.exit()

# Display the remote shell's command output:
print(cmdOutput)
print("----")

# -----------------------------------------------------------------
# Now for the 2nd SendReqExe (on the same connection,
# but on a separate logical channel).
# -----------------------------------------------------------------

channelNum = ssh.OpenSessionChannel()
if (channelNum < 0):
    print(ssh.lastErrorText())
    sys.exit()

cmd = "nslookup chilkatsoft.com\n"
success = ssh.SendReqExec(channelNum,cmd)
if (success == False):
    print(ssh.lastErrorText())
    sys.exit()

pollTimeoutMs = 2000
n = ssh.ChannelReadAndPoll(channelNum,pollTimeoutMs)
if (n < 0):
    print(ssh.lastErrorText())
    sys.exit()

success = ssh.ChannelSendClose(channelNum)
if (success == False):
    print(ssh.lastErrorText())
    sys.exit()

success = ssh.ChannelReceiveToClose(channelNum)
if (success == False):
    print(ssh.lastErrorText())
    sys.exit()

cmdOutput = ssh.getReceivedText(channelNum,"ansi")
if (ssh.get_LastMethodSuccess() == False):
    print(ssh.lastErrorText())
    sys.exit()

print(cmdOutput)