Java

Set a TTY Mode for an SSH PTY Request

Demonstrates the Chilkat Ssh.SetTtyMode method, which adds or updates one TTY mode to be included in a later SendReqPty request. The first argument is the mode name and the second is its integer value. Call it once per mode, before requesting the PTY.

Background: TTY modes are the terminal settings a PTY is created with — the same knobs stty exposes. The classic use is SetTtyMode("ECHO", 0), which stops the terminal from echoing input; that is how a password prompt keeps typed characters off the screen. Modes accumulate on the object and are sent with the next PTY request.

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Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    //  Demonstrates the Ssh.SetTtyMode method, which adds or updates one TTY mode to be included in
    //  a later SendReqPty request.  The 1st argument is the mode name and the 2nd is its integer
    //  value.  Call it once per mode, before SendReqPty.

    CkSsh ssh = new CkSsh();

    int sshPort = 22;
    success = ssh.Connect("ssh.example.com",sshPort);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    //  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.
    String password = "mySshPassword";

    success = ssh.AuthenticatePw("mySshLogin",password);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    //  Open a session channel.  A negative return value indicates failure.
    int channelNum = ssh.OpenSessionChannel();
    if (channelNum < 0) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    //  Request that the allocated terminal not echo input.
    success = ssh.SetTtyMode("ECHO",0);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    //  The modes set above are included in the PTY request.
    success = ssh.SendReqPty(channelNum,"xterm",80,24,0,0);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    success = ssh.SendReqShell(channelNum);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    ssh.Disconnect();
  }
}