Swift

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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func chilkatTest() {
    var success: Bool = 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.

    let ssh = CkoSsh()!

    var sshPort: Int = 22
    success = ssh.connect(hostname: "ssh.example.com", port: sshPort)
    if success == false {
        print("\(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.
    var password: String? = "mySshPassword"

    success = ssh.authenticatePw(login: "mySshLogin", password: password)
    if success == false {
        print("\(ssh.lastErrorText!)")
        return
    }

    //  Open a session channel.  A negative return value indicates failure.
    var channelNum: Int = ssh.openSessionChannel().intValue
    if channelNum < 0 {
        print("\(ssh.lastErrorText!)")
        return
    }

    //  Request that the allocated terminal not echo input.
    success = ssh.setTtyMode(name: "ECHO", value: 0)
    if success == false {
        print("\(ssh.lastErrorText!)")
        return
    }

    //  The modes set above are included in the PTY request.
    success = ssh.sendReqPty(channelNum: channelNum, xTermEnvVar: "xterm", widthInChars: 80, heightInRows: 24, pixWidth: 0, pixHeight: 0)
    if success == false {
        print("\(ssh.lastErrorText!)")
        return
    }

    success = ssh.sendReqShell(channelNum: channelNum)
    if success == false {
        print("\(ssh.lastErrorText!)")
        return
    }

    ssh.disconnect()

}