SSH ChannelReceiveUntilMatchN (Match Any of Several Prompts)

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Demonstrates ChannelReceiveUntilMatchN, which receives until any one of several patterns is matched. This is useful when driving an interactive session where the shell prompt differs from device to device.

Note: This example deliberately requests a PTY. Matching a shell prompt only works in an interactive session — without a PTY the shell runs non-interactively and never prints a prompt at all. For scripted use, omit the PTY and match on a marker your own command echoes.

var
success: Boolean;
ssh: HCkSsh;
saPrompts: HCkStringArray;
hostname: PWideChar;
port: Integer;
password: PWideChar;
channelNum: Integer;
termType: PWideChar;
widthInChars: Integer;
heightInChars: Integer;
pixWidth: Integer;
pixHeight: Integer;
caseSensitive: Boolean;
cmdOutput: PWideChar;

begin
success := False;

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

//  Demonstrates ChannelReceiveUntilMatchN, which receives until ANY one of several patterns is
//  matched.  This is useful when driving an interactive session where the shell prompt varies
//  from device to device.
//  
//  Note: This example deliberately DOES request a PTY.  Matching a shell prompt only works in an
//  interactive session -- without a PTY the shell runs non-interactively and never prints a
//  prompt at all.  For scripted use where no prompt is needed, omit the PTY and match on a
//  marker your own command echoes instead.

ssh := CkSsh_Create();

//  The remote shell prompt may be any of these, depending on the device.
saPrompts := CkStringArray_Create();
CkStringArray_Append(saPrompts,'~$');
CkStringArray_Append(saPrompts,'mars#');
CkStringArray_Append(saPrompts,'jupiter%');
CkStringArray_Append(saPrompts,'chilkat$');
CkStringArray_Append(saPrompts,'admin>');

hostname := 'ssh.example.com';
port := 22;
success := CkSsh_Connect(ssh,hostname,port);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    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 := CkSsh_AuthenticatePw(ssh,'mySshLogin',password);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;

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

//  Request a pseudo-terminal so the shell runs interactively and prints prompts.  A "dumb"
//  terminal is used so that ANSI escape sequences are not mixed into the output.
termType := 'dumb';
widthInChars := 120;
heightInChars := 40;
pixWidth := 0;
pixHeight := 0;
success := CkSsh_SendReqPty(ssh,channelNum,termType,widthInChars,heightInChars,pixWidth,pixHeight);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;

success := CkSsh_SendReqShell(ssh,channelNum);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;

//  IMPORTANT: Set a read timeout before receiving until a match.  ReadTimeoutMs defaults to 0,
//  which means no limit -- without it, this call waits forever if the received data never
//  contains a match.
CkSsh_putReadTimeoutMs(ssh,15000);

caseSensitive := True;

//  Read the initial login text up to the first prompt.
success := CkSsh_ChannelReceiveUntilMatchN(ssh,channelNum,saPrompts,'utf-8',caseSensitive);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;

cmdOutput := CkSsh__getReceivedText(ssh,channelNum,'utf-8');
if (CkSsh_getLastMethodSuccess(ssh) = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;
Memo1.Lines.Add(cmdOutput);

//  ---- 1st command ----
success := CkSsh_ChannelSendString(ssh,channelNum,'cd /tmp' + #10,'utf-8');
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;

success := CkSsh_ChannelReceiveUntilMatchN(ssh,channelNum,saPrompts,'utf-8',caseSensitive);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;

//  Retrieving the text also clears the receive buffer, which matters: if a prompt were left
//  buffered, the next receive would match it immediately and return the wrong output.
cmdOutput := CkSsh__getReceivedText(ssh,channelNum,'utf-8');
if (CkSsh_getLastMethodSuccess(ssh) = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;
Memo1.Lines.Add(cmdOutput);

//  ---- 2nd command ----
success := CkSsh_ChannelSendString(ssh,channelNum,'ls' + #10,'utf-8');
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;

success := CkSsh_ChannelReceiveUntilMatchN(ssh,channelNum,saPrompts,'utf-8',caseSensitive);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;

cmdOutput := CkSsh__getReceivedText(ssh,channelNum,'utf-8');
if (CkSsh_getLastMethodSuccess(ssh) = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;
Memo1.Lines.Add(cmdOutput);

//  Finish the session.
success := CkSsh_ChannelSendEof(ssh,channelNum);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;

success := CkSsh_ChannelReceiveToClose(ssh,channelNum);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;

cmdOutput := CkSsh__getReceivedText(ssh,channelNum,'utf-8');
if (CkSsh_getLastMethodSuccess(ssh) = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh));
    Exit;
  end;
Memo1.Lines.Add(cmdOutput);

CkSsh_Disconnect(ssh);

CkSsh_Dispose(ssh);
CkStringArray_Dispose(saPrompts);