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

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
ssh: HCkSsh;
port: Integer;
success: Boolean;
channelNum: Integer;
sbCommands: HCkStringBuilder;

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

ssh := CkSsh_Create();

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

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

// Start a shell session.
// (The QuickShell method was added in Chilkat v9.5.0.65)
channelNum := CkSsh_QuickShell(ssh);
if (channelNum < 0) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    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 := CkStringBuilder_Create();
CkStringBuilder_Append(sbCommands,'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.
CkStringBuilder_Append(sbCommands,'echo THIS ''IS'' THE END OF THE SCRIPT' + #10);

// Send the commands..
success := CkSsh_ChannelSendString(ssh,channelNum,CkStringBuilder__getAsString(sbCommands),'ansi');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    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 := CkSsh_ChannelSendEof(ssh,channelNum);

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

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

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

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

CkSsh_Dispose(ssh);
CkStringBuilder_Dispose(sbCommands);

end;