Delphi ActiveX

Get the Type of an Active SSH Channel

Demonstrates the Chilkat Ssh.GetChannelType method, which returns the type of the channel at a zero-based enumeration index. The only argument is the index — an enumeration position, not a channel number. Values include session, x11, forwarded-tcpip, and direct-tcpip.

Background: Paired with GetChannelNumber, this turns the channel collection into a readable inventory of what a connection is currently doing — which channels are running commands (session) versus tunneling TCP traffic (direct-tcpip). That is valuable for diagnostics and for application code that manages several channel kinds at once. An out-of-range index causes the string-returning method to report failure.

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var
success: Integer;
ssh: TChilkatSsh;
sshPort: Integer;
password: WideString;
channelNum: Integer;
n: Integer;
i: Integer;
chNum: Integer;
chType: WideString;

begin
success := 0;

//  Demonstrates the Ssh.GetChannelType method, which returns the type of the channel at a
//  zero-based enumeration index.  The only argument is the index, which is an enumeration
//  position and not a channel number.  Values include "session" and "direct-tcpip".

ssh := TChilkatSsh.Create(Self);

sshPort := 22;
success := ssh.Connect('ssh.example.com',sshPort);
if (success = 0) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

//  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
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

channelNum := ssh.OpenSessionChannel();
if (channelNum < 0) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

//  Enumerate the active channels and report each one's number and type.
n := ssh.NumOpenChannels;

for i := 0 to n - 1 do
  begin
    chNum := ssh.GetChannelNumber(i);
    chType := ssh.GetChannelType(i);
    if (ssh.LastMethodSuccess = 0) then
      begin
        Memo1.Lines.Add(ssh.LastErrorText);
        Exit;
      end;
    Memo1.Lines.Add('Channel ' + IntToStr(chNum) + ' is of type ' + chType);
  end;

ssh.Disconnect();