(Delphi ActiveX) Multiple SendReqExec on Same Connection

Shows how to execute a series of commands on an SSH server and retrieve each command's output (using SendReqExec). Each call to SendReqExec requires its own logical channel. This is not a separate SSH connection -- it's simply a new session channel on the existing SSH connection.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
ssh: TChilkatSsh;
hostname: WideString;
port: Integer;
success: Integer;
channelNum: Integer;
cmd: WideString;
pollTimeoutMs: Integer;
n: Integer;
cmdOutput: WideString;

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

ssh := TChilkatSsh.Create(Self);

// Hostname may be an IP address or domain:
hostname := '172.16.16.46';
port := 22;

success := ssh.Connect(hostname,port);
if (success = 0) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

// If receiving output from a command stalls for more than 5 seconds, then stop waiting.
ssh.IdleTimeoutMs := 5000;

// Authenticate using login/password:
success := ssh.AuthenticatePw('myLogin','myPassword');
if (success = 0) then
  begin
    Memo1.Lines.Add(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
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

// Request a directory listing on the remote server:
// If your server is Linux/UNIX, change the string from "dir" to "ls"
// Note: Some SSH servers require a CRLF instead of a bare-LF
cmd := 'ls -al' + #10;
success := ssh.SendReqExec(channelNum,cmd);
if (success = 0) then
  begin
    Memo1.Lines.Add(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
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

// Close the channel:
success := ssh.ChannelSendClose(channelNum);
if (success = 0) then
  begin
    Memo1.Lines.Add(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 = 0) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

// Get the accumulated output of the command:

cmdOutput := ssh.GetReceivedText(channelNum,'ansi');
if (ssh.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

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

// -----------------------------------------------------------------
// Now for the 2nd SendReqExe (on the same connection,
// but on a separate logical channel).
// -----------------------------------------------------------------

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

cmd := 'nslookup chilkatsoft.com' + #10;
success := ssh.SendReqExec(channelNum,cmd);
if (success = 0) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

pollTimeoutMs := 2000;
n := ssh.ChannelReadAndPoll(channelNum,pollTimeoutMs);
if (n < 0) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

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

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

cmdOutput := ssh.GetReceivedText(channelNum,'ansi');
if (ssh.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add(cmdOutput);
end;