VB.NET

Clear Accumulated SSH TTY Modes

Demonstrates the Chilkat Ssh.ClearTtyModes method, which clears all TTY modes previously added with SetTtyMode. It takes no arguments. The next SendReqPty will not include the cleared modes.

Background: Because TTY modes accumulate on the Ssh object, they would otherwise carry over into every later PTY request on that object. ClearTtyModes resets that state — useful when one Ssh object opens several channels and each needs different terminal settings, or when you want a PTY created with the server's defaults.

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Dim success As Boolean = False

'  Demonstrates the Ssh.ClearTtyModes method, which clears all TTY modes previously added with
'  SetTtyMode.  It takes no arguments.

Dim ssh As New Chilkat.Ssh

Dim sshPort As Integer = 22
success = ssh.Connect("ssh.example.com",sshPort)
If (success = False) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
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.
Dim password As String = "mySshPassword"

success = ssh.AuthenticatePw("mySshLogin",password)
If (success = False) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


'  Add a TTY mode, then discard it before requesting the PTY.
success = ssh.SetTtyMode("ECHO",0)
If (success = False) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


'  Clear the accumulated TTY modes.  The next SendReqPty will not include them.
ssh.ClearTtyModes()

'  Open a session channel.  A negative return value indicates failure.
Dim channelNum As Integer = ssh.OpenSessionChannel()
If (channelNum < 0) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


'  This PTY request carries no custom TTY modes.
success = ssh.SendReqPty(channelNum,"xterm",80,24,0,0)
If (success = False) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


ssh.Disconnect()