SSH Remote Shell

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

Download Chilkat 32-bit SSH / SFTP ActiveX (.msi)

Download All 32-bit Chilkat ActiveX Components (.zip)

Download All 64-bit Chilkat ActiveX Components (.zip)

uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls,
    CHILKATRSALib_TLB,
    CHILKATSSHLib_TLB,
    OleCtrls;

...

procedure TForm1.Button1Click(Sender: TObject);
var
ssh: TChilkatSsh;
success: Integer;
hostname: String;
port: Integer;
channelNum: Integer;
termType: String;
widthInChars: Integer;
heightInChars: Integer;
pixWidth: Integer;
pixHeight: Integer;
n: Integer;
pollTimeoutMs: Integer;
cmdOutput: String;

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

ssh := TChilkatSsh.Create(Self);

//  Any string automatically begins a fully-functional 30-day trial.
success := ssh.UnlockComponent('30-day trial');
if (success <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  Connect to an SSH server:

//  Hostname may be an IP address or hostname:
hostname := 'www.some-ssh-server.com';
port := 22;

success := ssh.Connect(hostname,port);
if (success <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  Wait a max of 5 seconds when reading responses..
ssh.IdleTimeoutMs := 5000;

//  Authenticate using login/password:
success := ssh.AuthenticatePw('myLogin','myPassword');
if (success <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

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

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

//  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 <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  Start a shell on the channel:
success := ssh.SendReqShell(channelNum);
if (success <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  Start a command in the remote shell.  This example
//  will send a "dir" command to retrieve the directory listing.
success := ssh.ChannelSendString(channelNum,'dir' + #13#10,'ansi');
if (success <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  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 <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    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) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  Close the channel:
success := ssh.ChannelSendClose(channelNum);
if (success <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    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 <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

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

cmdOutput := ssh.GetReceivedText(channelNum,'ansi');
if (cmdOutput = NULL ) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  Display the remote shell's command output:
Memo1.Lines.Add(cmdOutput);

//  Disconnect
ssh.Disconnect();
end;