(Excel) SSH Remote Shell

Demonstrates how to start a shell on a remote SSH server, run a command, and retrieve the output.

Download Excel Class Modules Chilkat Excel Class Modules

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

Dim ssh As Chilkat.Ssh
Set ssh = Chilkat.NewSsh

' Hostname may be an IP address or hostname:

hostname = "www.some-ssh-server.com"

port = 22

' Connect to an SSH server:

success = ssh.Connect(hostname,port)
If (success <> True) Then
    Debug.Print ssh.LastErrorText
    Exit Sub
End If

' Wait a max of 5 seconds when reading responses..
ssh.IdleTimeoutMs = 5000

' Authenticate using login/password:
success = ssh.AuthenticatePw("myLogin","myPassword")
If (success <> True) Then
    Debug.Print ssh.LastErrorText
    Exit Sub
End If

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

channelNum = ssh.OpenSessionChannel()
If (channelNum < 0) Then
    Debug.Print ssh.LastErrorText
    Exit Sub
End If

' Some SSH servers require a pseudo-terminal
' If so, include the call to SendReqPty.  If not, then 
' comment out the call to SendReqPty.
' Note: The 2nd argument of SendReqPty is the terminal type,
' which should be something like "xterm", "vt100", "dumb", etc.
' A "dumb" terminal is one that cannot process escape sequences.
' Smart terminals, such as "xterm", "vt100", etc. process
' escape sequences.  If you select a type of smart terminal,
' your application will receive these escape sequences
' included in the command's output.  Use "dumb" if you do not
' want to receive escape sequences.  (Assuming your SSH
' server recognizes "dumb" as a standard dumb terminal.)

termType = "dumb"

widthInChars = 120

heightInChars = 40
' Use 0 for pixWidth and pixHeight when the dimensions
' are set in number-of-chars.

pixWidth = 0

pixHeight = 0
success = ssh.SendReqPty(channelNum,termType,widthInChars,heightInChars,pixWidth,pixHeight)
If (success <> True) Then
    Debug.Print ssh.LastErrorText
    Exit Sub
End If

' Start a shell on the channel:
success = ssh.SendReqShell(channelNum)
If (success <> True) Then
    Debug.Print ssh.LastErrorText
    Exit Sub
End If

' Start a command in the remote shell.  This example
' will send a "ls" command to retrieve the directory listing.
success = ssh.ChannelSendString(channelNum,"ls" & vbCrLf,"ansi")
If (success <> True) Then
    Debug.Print ssh.LastErrorText
    Exit Sub
End If

' Send an EOF.  This tells the server that no more data will 
' be sent on this channel.  The channel remains open, and
' the SSH client may still receive output on this channel.
success = ssh.ChannelSendEof(channelNum)
If (success <> True) Then
    Debug.Print ssh.LastErrorText
    Exit Sub
End If

' 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) Then
    Debug.Print ssh.LastErrorText
    Exit Sub
End If

' Close the channel:
success = ssh.ChannelSendClose(channelNum)
If (success <> True) Then
    Debug.Print ssh.LastErrorText
    Exit Sub
End If

' 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) Then
    Debug.Print ssh.LastErrorText
    Exit Sub
End If

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

cmdOutput = ssh.GetReceivedText(channelNum,"ansi")
If (ssh.LastMethodSuccess <> True) Then
    Debug.Print ssh.LastErrorText
    Exit Sub
End If

' Display the remote shell's command output:
Debug.Print cmdOutput

' Disconnect
ssh.Disconnect