VBScript

Check Whether an SSH Channel is Open

Demonstrates the Chilkat Ssh.ChannelIsOpen method, which reports whether a channel number identifies a channel Chilkat currently considers open for application I/O. The only argument is the channel number. This example checks the channel before and after sending CLOSE.

Background: Because one SSH connection can carry many channels with independent lifetimes, code that manages several needs a way to ask whether a given one is still usable. This returns false for invalid or nonexistent channel numbers, after a local Disconnect, once remote closure is processed, and immediately after ChannelSendClose — which marks the channel locally closed without waiting for the remote side.

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VBScript

Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

success = 0

'  Demonstrates the Ssh.ChannelIsOpen method, which reports whether a channel number identifies
'  a channel Chilkat currently considers open for application I/O.  The only argument is the
'  channel number.

set ssh = CreateObject("Chilkat.Ssh")

sshPort = 22
success = ssh.Connect("ssh.example.com",sshPort)
If (success = 0) Then
    outFile.WriteLine(ssh.LastErrorText)
    WScript.Quit
End If

'  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 = 0) Then
    outFile.WriteLine(ssh.LastErrorText)
    WScript.Quit
End If

'  Open a session channel.  A negative return value indicates failure.
channelNum = ssh.OpenSessionChannel()
If (channelNum < 0) Then
    outFile.WriteLine(ssh.LastErrorText)
    WScript.Quit
End If

If (ssh.ChannelIsOpen(channelNum)) Then
    outFile.WriteLine("The channel is open.")
Else
    outFile.WriteLine("The channel is not open.")
End If

'  Send CLOSE, which immediately marks the channel locally closed.
success = ssh.ChannelSendClose(channelNum)
If (success = 0) Then
    outFile.WriteLine(ssh.LastErrorText)
    WScript.Quit
End If

If (ssh.ChannelIsOpen(channelNum)) Then
    outFile.WriteLine("Still open.")
Else
    outFile.WriteLine("The channel is now closed.")
End If

ssh.Disconnect 

outFile.Close