(Delphi ActiveX) Using sudo in an SSH Shell Session

See more SSH Examples

Demonstrates how to run a command as sudo in a shell session.

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;
port: Integer;
success: Integer;
channelNum: Integer;
sbCommands: TChilkatStringBuilder;

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

ssh := TChilkatSsh.Create(Self);

port := 22;
success := ssh.Connect('the-ssh-server.com',port);
if (success <> 1) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

// Authenticate using login/password:
success := ssh.AuthenticatePw('theSshLogin','theSshPassword');
if (success <> 1) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

// Start a shell session.
// (The QuickShell method was added in Chilkat v9.5.0.65)
channelNum := ssh.QuickShell();
if (channelNum < 0) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

// Construct a StringBuilder with our command ("ls") run with "sudo"
// Note: The line-endings are potentially important.  Some SSH servers may
// require either LF or CRLF line endings.  (Unix/Linux/OSX servers typically
// use bare-LF line endings.  Windows servers likely use CRLF line endings.)

// Using "sudo -S" causes the sudo prompt to be written to stderr,
// and the password is read from stdin (i.e. from the echo command ouput).
// The sudo commands -p option allows us to set the prompt, and we can set it to
// the empty string, thus eliminating the prompt from the stderr completely.
// This allows us to run the command as root (super-user) with no prompt.
sbCommands := TChilkatStringBuilder.Create(Self);
sbCommands.Append('echo "theSshPassword" | sudo -S -p "" ls' + #10);

// Add another command to echo a marker string that
// we'll use in ChannelReceiveUntilMatch below.
// The use of single quotes around 'IS' is a trick so that the output
// of the command is "THIS IS THE END OF THE SCRIPT", but the terminal echo
// includes the single quotes.  This allows us to read until we see the actual
// output of the last command.
sbCommands.Append('echo THIS ''IS'' THE END OF THE SCRIPT' + #10);

// Send the commands..
success := ssh.ChannelSendString(channelNum,sbCommands.GetAsString(),'ansi');
if (success <> 1) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

// Send an EOF to indicate no more commands will be sent.
// For brevity, we're not checking the return values of each method call.
// Your code should check the success/failure of each call.
success := ssh.ChannelSendEof(channelNum);

// Receive output up to our marker.
success := ssh.ChannelReceiveUntilMatch(channelNum,'THIS IS THE END OF THE SCRIPT','ansi',1);

// Close the channel.
// It is important to close the channel only after receiving the desired output.
success := ssh.ChannelSendClose(channelNum);

// Get any remaining output..
success := ssh.ChannelReceiveToClose(channelNum);

// Get the complete output for all the commands in the session.
Memo1.Lines.Add('--- output ----');
Memo1.Lines.Add(ssh.GetReceivedText(channelNum,'ansi'));
end;