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 session channel. This is not a separate TCP/IP connection -- it's simply a new session channel on the existing connection. The sequence of Chilkat SSH calls would look like this:

Connect
AuthenticatePw (or AuthenticatePk)

OpenSessionChannel
SendReqExec
<retrieve command output...>
SendChannelClose
ChannelReceiveToClose (to make sure all remaining output is received)

OpenSessionChannel
SendReqExec
<retrieve command output...>
SendChannelClose
ChannelReceiveToClose (to make sure all remaining output is received)

...

OpenSessionChannel
SendReqExec
<retrieve command output...>
SendChannelClose
ChannelReceiveToClose (to make sure all remaining output is received)

Disconnect

Download Chilkat Ruby Library

require 'chilkat'

#  Important: It is helpful to send the contents of the
#  ssh.LastErrorText property when requesting support.

ssh = Chilkat::CkSsh.new()

#  Any string automatically begins a fully-functional 30-day trial.
success = ssh.UnlockComponent("Anything for 30-day trial")
if (success != true)
    print ssh.lastErrorText() + "\n"
    exit
end

#  Connect to an SSH server:

#  Hostname may be an IP address or hostname:
hostname = "192.168.1.117"
port = 22

success = ssh.Connect(hostname,port)
if (success != true)
    print ssh.lastErrorText() + "\n"
    exit
end

#  Wait a max of 5 seconds when reading responses..
ssh.put_IdleTimeoutMs(5000)

#  Authenticate using login/password:
success = ssh.AuthenticatePw("myLogin","myPassword")
if (success != true)
    print ssh.lastErrorText() + "\n"
    exit
end

#  Open a session channel.  (It is possible to have multiple
#  session channels open simultaneously.)

channelNum = ssh.OpenSessionChannel()
if (channelNum < 0)
    print ssh.lastErrorText() + "\n"
    exit
end

#  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
success = ssh.SendReqExec(channelNum,"ls -al\n")
if (success != true)
    print ssh.lastErrorText() + "\n"
    exit
end

#  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() + "\n"
    exit
end

#  Close the channel:
success = ssh.ChannelSendClose(channelNum)
if (success != true)
    print ssh.lastErrorText() + "\n"
    exit
end

#  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 != true)
    print ssh.lastErrorText() + "\n"
    exit
end

#  Let's pickup the accumulated output of the command:

cmdOutput = ssh.getReceivedText(channelNum,"ansi")
if (cmdOutput == nil )
    print ssh.lastErrorText() + "\n"
    exit
end

#  Display the remote shell's command output:
print cmdOutput + "\n";
print "----" + "\n";

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

channelNum = ssh.OpenSessionChannel()
if (channelNum < 0)
    print ssh.lastErrorText() + "\n"
    exit
end

success = ssh.SendReqExec(channelNum,"nslookup chilkatsoft.com\n")
if (success != true)
    print ssh.lastErrorText() + "\n"
    exit
end

pollTimeoutMs = 2000
n = ssh.ChannelReadAndPoll(channelNum,pollTimeoutMs)
if (n < 0)
    print ssh.lastErrorText() + "\n"
    exit
end

success = ssh.ChannelSendClose(channelNum)
if (success != true)
    print ssh.lastErrorText() + "\n"
    exit
end

success = ssh.ChannelReceiveToClose(channelNum)
if (success != true)
    print ssh.lastErrorText() + "\n"
    exit
end

cmdOutput = ssh.getReceivedText(channelNum,"ansi")
if (cmdOutput == nil )
    print ssh.lastErrorText() + "\n"
    exit
end

print cmdOutput + "\n";

#  Disconnect
ssh.Disconnect()