Module org.jline.terminal
Package org.jline.terminal.impl

Class PosixSysTerminal

java.lang.Object
org.jline.terminal.impl.AbstractTerminal
org.jline.terminal.impl.AbstractPosixTerminal
org.jline.terminal.impl.PosixSysTerminal
All Implemented Interfaces:
Closeable, Flushable, AutoCloseable, Sized, TerminalExt, Terminal
public class PosixSysTerminal extends AbstractPosixTerminal
Terminal implementation for POSIX systems using system streams.

The PosixSysTerminal class provides a terminal implementation for POSIX systems (Linux, macOS, etc.) that uses the system standard input and output streams. It extends the AbstractPosixTerminal class and adds functionality specific to system stream-based terminals.

This implementation is used when connecting to the actual system terminal, such as when running a console application in a terminal window. It provides access to the standard input and output streams, allowing for interaction with the user through the terminal.

Key features of this implementation include:

  • Direct access to system standard input and output
  • Support for terminal attributes and size changes
  • Support for non-blocking I/O
  • Automatic restoration of terminal state on shutdown
See Also:

  • Field Details

  • Constructor Details

    • PosixSysTerminal

      public PosixSysTerminal(String name, String type, Pty pty, Charset encoding, boolean nativeSignals, Terminal.SignalHandler signalHandler) throws IOException
      Creates a POSIX system terminal backed by the provided PTY, using the same charset for input and output, and optionally enabling native signal handling.
      Parameters:
      name - the terminal name
      type - the terminal type (TERM)
      pty - the pseudo-terminal providing slave input/output streams for the terminal
      encoding - the charset used for both input and output encoding
      nativeSignals - if true, native OS signal handlers will be registered
      signalHandler - the initial handler to install for native signals
      Throws:
      IOException - if an I/O error occurs while initializing the terminal

    • PosixSysTerminal

      public PosixSysTerminal(String name, String type, Pty pty, Charset encoding, Charset inputEncoding, Charset outputEncoding, boolean nativeSignals, Terminal.SignalHandler signalHandler) throws IOException
      Creates a POSIX system terminal backed by the given PTY and character encodings, without a TerminalProvider.
      Parameters:
      name - the terminal name
      type - the terminal type (TERM)
      pty - the pseudoterminal providing slave input/output streams
      encoding - the primary charset for the terminal
      inputEncoding - the charset used for input decoding
      outputEncoding - the charset used for output encoding
      nativeSignals - whether native signal handlers should be registered
      signalHandler - the initial handler to install for native signals
      Throws:
      IOException - if an I/O error occurs while initializing the terminal

    • PosixSysTerminal

      public PosixSysTerminal(TerminalProvider provider, String name, String type, Pty pty, Charset encoding, Charset inputEncoding, Charset outputEncoding, boolean nativeSignals, Terminal.SignalHandler signalHandler) throws IOException
      Create a POSIX system terminal backed by the provided PTY, initializing non-blocking input/output, reader/writer encodings, and optional native signal handlers.
      Parameters:
      provider - optional TerminalProvider used for native signal registration; may be null
      name - the terminal name
      type - the terminal type (TERM)
      pty - the PTY whose slave streams back this terminal
      encoding - the primary charset for the terminal
      inputEncoding - the charset used for the terminal reader
      outputEncoding - the charset used for the terminal writer
      nativeSignals - if true, register native OS signal handlers for all signals
      signalHandler - the initial handler to install for native signals; if `SignalHandler.SIG_DFL`, default native handlers will be registered
      Throws:
      IOException - if the PTY streams or terminal I/O cannot be initialized

  • Method Details

    • handle

      public Terminal.SignalHandler handle(Terminal.Signal signal, Terminal.SignalHandler handler)
      Install a new handler for the given signal and synchronize native registration when the handler changes. If the new handler differs from the previous one, registers a native default handler when the new handler is `SignalHandler.SIG_DFL`; otherwise registers a native handler that will raise the signal.
      Specified by:
      handle in interface Terminal
      Overrides:
      handle in class AbstractTerminal
      Parameters:
      signal - the signal to update
      handler - the new handler to install for the signal
      Returns:
      the previous handler for the signal
      See Also:

    • getAttributes

      public Attributes getAttributes()
      Description copied from interface: Terminal
      Returns the current terminal attributes.

      Terminal attributes control various aspects of terminal behavior, including:

      • Input processing - How input characters are processed (e.g., character mapping, parity checking)
      • Output processing - How output characters are processed (e.g., newline translation)
      • Control settings - Hardware settings like baud rate and character size
      • Local settings - Terminal behavior settings like echo, canonical mode, and signal generation
      • Control characters - Special characters like EOF, interrupt, and erase

      The returned Attributes object is a copy of the terminal's current attributes and can be safely modified without affecting the terminal until it is applied using Terminal.setAttributes(Attributes). This allows for making multiple changes to the attributes before applying them all at once.

      Example usage:

       Terminal terminal = TerminalBuilder.terminal();

 // Get current attributes
 Attributes attrs = terminal.getAttributes();

 // Modify attributes
 attrs.setLocalFlag(LocalFlag.ECHO, false);      // Disable echo
 attrs.setInputFlag(InputFlag.ICRNL, false);     // Disable CR to NL mapping
 attrs.setControlChar(ControlChar.VMIN, 1);      // Set minimum input to 1 character
 attrs.setControlChar(ControlChar.VTIME, 0);     // Set timeout to 0 deciseconds

 // Apply modified attributes
 terminal.setAttributes(attrs);
      Specified by:
      getAttributes in interface Terminal
      Overrides:
      getAttributes in class AbstractPosixTerminal
      Returns:
      a copy of the terminal's current attributes
      See Also:

    • setAttributes

      public void setAttributes(Attributes attr)
      Description copied from interface: Terminal
      Sets the terminal attributes to the specified values.

      This method applies the specified attributes to the terminal, changing its behavior according to the settings in the Attributes object. The terminal makes a copy of the provided attributes, so further modifications to the attr object will not affect the terminal until this method is called again.

      Terminal attributes control various aspects of terminal behavior, including input and output processing, control settings, local settings, and special control characters. Changing these attributes allows for fine-grained control over how the terminal processes input and output.

      Common attribute modifications include:

      • Disabling echo for password input
      • Enabling/disabling canonical mode for line-by-line or character-by-character input
      • Disabling signal generation for custom handling of Ctrl+C and other control sequences
      • Changing control characters like the interrupt character or end-of-file character

      For convenience, the Terminal.enterRawMode() method provides a pre-configured set of attributes suitable for full-screen interactive applications.

      Example usage:

       Terminal terminal = TerminalBuilder.terminal();

 // Save original attributes for later restoration
 Attributes originalAttrs = terminal.getAttributes();

 try {
     // Create and configure new attributes
     Attributes attrs = new Attributes(originalAttrs);
     attrs.setLocalFlag(LocalFlag.ECHO, false);      // Disable echo for password input
     attrs.setLocalFlag(LocalFlag.ICANON, false);    // Disable canonical mode

     // Apply the new attributes
     terminal.setAttributes(attrs);

     // Use terminal with modified attributes...
 } finally {
     // Restore original attributes
     terminal.setAttributes(originalAttrs);
 }
      Specified by:
      setAttributes in interface Terminal
      Overrides:
      setAttributes in class AbstractPosixTerminal
      Parameters:
      attr - the attributes to apply to the terminal
      See Also:

    • supportsGraphemeClusterMode

      public boolean supportsGraphemeClusterMode()
      Determine if grapheme cluster mode is supported for this terminal.
      Specified by:
      supportsGraphemeClusterMode in interface Terminal
      Overrides:
      supportsGraphemeClusterMode in class AbstractTerminal
      Returns:
      `true` if grapheme cluster mode is supported, `false` otherwise; on Windows this always returns `false` to avoid writing a DECRQM probe to raw stdout/stderr that may not be a real PTY and could contaminate process output.
      See Also:

    • reader

      public NonBlockingReader reader()
      Description copied from interface: Terminal
      Retrieve the Reader for this terminal. This is the standard way to read input from this terminal. The reader is non blocking.

      The returned reader is owned by this terminal and will be closed when the terminal is closed. Callers should not close it directly.

      Returns:
      The non blocking reader

    • writer

      public PrintWriter writer()
      Description copied from interface: Terminal
      Retrieve the Writer for this terminal. This is the standard way to write to this terminal.

      The returned writer is owned by this terminal and will be closed when the terminal is closed. Callers should not close it directly.

      Returns:
      The writer

    • input

      public InputStream input()
      Description copied from interface: Terminal
      Retrieve the input stream for this terminal. In some rare cases, there may be a need to access the terminal input stream directly. In the usual cases, use the Terminal.reader() instead.

      The returned stream is owned by this terminal and will be closed when the terminal is closed. Callers should not close it directly.

      Returns:
      The input stream
      See Also:

    • output

      public OutputStream output()
      Description copied from interface: Terminal
      Retrieve the output stream for this terminal. In some rare cases, there may be a need to access the terminal output stream directly. In the usual cases, use the Terminal.writer() instead.

      The returned stream is owned by this terminal and will be closed when the terminal is closed. Callers should not close it directly.

      Returns:
      The output stream
      See Also:

    • doClose

      protected void doClose() throws IOException
      Closes the terminal and releases its resources: flushes pending output, removes the shutdown hook, unregisters any native signal handlers, performs superclass shutdown, and closes the reader.
      Overrides:
      doClose in class AbstractPosixTerminal
      Throws:
      IOException - if an I/O error occurs while flushing or closing the terminal streams