Class UnixLikeTTYTerminal

All Implemented Interfaces:
Scrollable, InputProvider, ExtendedTerminal, Terminal, Closeable, AutoCloseable
Direct Known Subclasses:
CygwinTerminal, UnixTerminal

public abstract class UnixLikeTTYTerminal extends UnixLikeTerminal
UnixLikeTerminal extends from ANSITerminal and defines functionality that is common to UnixTerminal and CygwinTerminal, like setting tty modes; echo, cbreak and minimum characters for reading as well as a shutdown hook to set the tty back to original state at the end.

If requested, it handles Control-C input to terminate the program, and hooks into Unix WINCH signal to detect when the user has resized the terminal, if supported by the JVM.

  • Field Details

    • ttyDev

      private final File ttyDev
    • sttyStatusToRestore

      private String sttyStatusToRestore
  • Constructor Details

    • UnixLikeTTYTerminal

      protected UnixLikeTTYTerminal(File ttyDev, InputStream terminalInput, OutputStream terminalOutput, Charset terminalCharset, UnixLikeTerminal.CtrlCBehaviour terminalCtrlCBehaviour) throws IOException
      Creates a UnixTerminal using a specified input stream, output stream and character set, with a custom size querier instead of using the default one. This way you can override size detection (if you want to force the terminal to a fixed size, for example). You also choose how you want ctrl+c key strokes to be handled.
      Parameters:
      ttyDev - TTY device file that is representing this terminal session, will be used when calling stty to make it operate on this session
      terminalInput - Input stream to read terminal input from
      terminalOutput - Output stream to write terminal output to
      terminalCharset - Character set to use when converting characters to bytes
      terminalCtrlCBehaviour - Special settings on how the terminal will behave, see UnixTerminalMode for more details
      Throws:
      IOException - If there was an I/O error while setting up the terminal
  • Method Details

    • acquire

      protected void acquire() throws IOException
      Description copied from class: UnixLikeTerminal
      Effectively taking over the terminal and enabling it for Lanterna to use, by turning off echo and canonical mode, adding resize listeners and optionally trap unix signals. This should be called automatically by the constructor of any end-user class extending from UnixLikeTerminal
      Overrides:
      acquire in class UnixLikeTerminal
      Throws:
      IOException - If there was an I/O error
    • realAcquire

      private void realAcquire() throws IOException
      Throws:
      IOException
    • registerTerminalResizeListener

      protected void registerTerminalResizeListener(Runnable onResize) throws IOException
      Specified by:
      registerTerminalResizeListener in class UnixLikeTerminal
      Throws:
      IOException
    • saveTerminalSettings

      protected void saveTerminalSettings() throws IOException
      Description copied from class: UnixLikeTerminal
      Stores the current terminal device settings (the ones that are modified through this interface) so that they can be restored later using UnixLikeTerminal.restoreTerminalSettings()
      Specified by:
      saveTerminalSettings in class UnixLikeTerminal
      Throws:
      IOException - If there was an I/O error when altering the terminal environment
    • restoreTerminalSettings

      protected void restoreTerminalSettings() throws IOException
      Description copied from class: UnixLikeTerminal
      Restores the terminal settings from last time UnixLikeTerminal.saveTerminalSettings() was called
      Specified by:
      restoreTerminalSettings in class UnixLikeTerminal
      Throws:
      IOException - If there was an I/O error when altering the terminal environment
    • keyEchoEnabled

      protected void keyEchoEnabled(boolean enabled) throws IOException
      Description copied from class: UnixLikeTerminal
      Enables or disable key echo mode, which means when the user press a key, the terminal will immediately print that key to the terminal. Normally for Lanterna, this should be turned off so the software can take the key as an input event, put it on the input queue and then depending on the code decide what to do with it.
      Specified by:
      keyEchoEnabled in class UnixLikeTerminal
      Parameters:
      enabled - true if key echo should be enabled, false otherwise
      Throws:
      IOException - If there was an I/O error when altering the terminal environment
    • canonicalMode

      protected void canonicalMode(boolean enabled) throws IOException
      Description copied from class: UnixLikeTerminal
      In canonical mode, data are accumulated in a line editing buffer, and do not become "available for reading" until line editing has been terminated by the user sending a line delimiter character. This is usually the default mode for a terminal. Lanterna wants to read each character as they are typed, without waiting for the final newline, so it will attempt to turn canonical mode off on initialization.
      Specified by:
      canonicalMode in class UnixLikeTerminal
      Parameters:
      enabled - true if canonical input mode should be enabled, false otherwise
      Throws:
      IOException - If there was an I/O error when altering the terminal environment
    • keyStrokeSignalsEnabled

      protected void keyStrokeSignalsEnabled(boolean enabled) throws IOException
      Description copied from class: UnixLikeTerminal
      This method causes certain keystrokes (at the moment only ctrl+c) to be passed in to the program as a regular KeyStroke instead of as a signal to the JVM process. For example, ctrl+c will normally send an interrupt that causes the JVM to shut down, but this method will make it pass in ctrl+c as a regular KeyStroke instead. You can of course still make ctrl+c kill the application through your own input handling if you like.

      Please note that this method is called automatically by lanterna to disable signals unless you define a system property "com.googlecode.lanterna.terminal.UnixTerminal.catchSpecialCharacters" and set it to the string "false".

      Specified by:
      keyStrokeSignalsEnabled in class UnixLikeTerminal
      Parameters:
      enabled - Pass in true if you want keystrokes to generate system signals (like process interrupt), false if you want lanterna to catch and interpret these keystrokes are regular keystrokes
      Throws:
      IOException - If there was an I/O error when attempting to disable special characters
      See Also:
    • runSTTYCommand

      protected String runSTTYCommand(String... parameters) throws IOException
      Throws:
      IOException
    • exec

      protected String exec(String... cmd) throws IOException
      Throws:
      IOException
    • getSTTYCommand

      private String getSTTYCommand()