Class AbstractPosixTerminal

java.lang.Object
org.jline.terminal.impl.AbstractTerminal
org.jline.terminal.impl.AbstractPosixTerminal
All Implemented Interfaces:
Closeable, Flushable, AutoCloseable, TerminalExt, Terminal
Direct Known Subclasses:
PosixPtyTerminal, PosixSysTerminal

public abstract class AbstractPosixTerminal extends AbstractTerminal
Base implementation for terminals on POSIX-compliant systems.

The AbstractPosixTerminal class provides a foundation for terminal implementations on POSIX-compliant systems such as Linux, macOS, and other Unix-like operating systems. It builds on the AbstractTerminal class and adds POSIX-specific functionality, particularly related to pseudoterminal (PTY) handling.

This class manages the interaction with the underlying PTY, handling terminal attributes, size changes, and other POSIX-specific terminal operations. It provides implementations for many of the abstract methods defined in AbstractTerminal, leaving only a few methods to be implemented by concrete subclasses.

Key features provided by this class include:

  • PTY management and interaction
  • Terminal attribute preservation and restoration
  • Size handling and window change signals
  • Cursor position detection

This class is designed to be extended by concrete implementations that target specific POSIX platforms or environments.

See Also:
  • Field Details

    • pty

      protected final Pty pty
    • originalAttributes

      protected final Attributes originalAttributes
  • Constructor Details

  • Method Details

    • getPty

      public Pty getPty()
    • 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);
       
      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);
       }
       
      Parameters:
      attr - the attributes to apply to the terminal
      See Also:
    • getSize

      public Size getSize()
      Description copied from interface: Terminal
      Retrieve the size of the visible window
      Returns:
      the visible terminal size
      See Also:
    • setSize

      public void setSize(Size size)
      Description copied from interface: Terminal
      Sets the size of the terminal.

      This method attempts to resize the terminal to the specified dimensions. Note that not all terminals support resizing, and the actual size after this operation may differ from the requested size depending on terminal capabilities and constraints.

      For virtual terminals or terminal emulators, this may update the internal size representation. For physical terminals, this may send appropriate escape sequences to adjust the viewable area.

      Parameters:
      size - the new terminal size (columns and rows)
      See Also:
    • doClose

      protected void doClose() throws IOException
      Overrides:
      doClose in class AbstractTerminal
      Throws:
      IOException
    • getCursorPosition

      public Cursor getCursorPosition(IntConsumer discarded)
      Description copied from interface: Terminal
      Query the terminal to report the cursor position. As the response is read from the input stream, some characters may be read before the cursor position is actually read. Those characters can be given back using org.jline.keymap.BindingReader#runMacro(String)
      Specified by:
      getCursorPosition in interface Terminal
      Overrides:
      getCursorPosition in class AbstractTerminal
      Parameters:
      discarded - a consumer receiving discarded characters
      Returns:
      null if cursor position reporting is not supported or a valid cursor position
    • getProvider

      public TerminalProvider getProvider()
      Description copied from interface: TerminalExt
      Returns the terminal provider that created this terminal.

      The terminal provider is responsible for creating and managing terminal instances on a specific platform. This method allows access to the provider that created this terminal, which can be useful for accessing provider-specific functionality or for creating additional terminals with the same provider.

      Returns:
      the TerminalProvider that created this terminal, or null if the terminal was created with no provider
      See Also:
    • getSystemStream

      public SystemStream getSystemStream()
      Description copied from interface: TerminalExt
      Returns the system stream associated with this terminal, if any.

      This method indicates whether the terminal is bound to a standard system stream (standard input, standard output, or standard error). Terminals that are connected to system streams typically represent the actual terminal window or console that the application is running in.

      Returns:
      the underlying system stream, which may be SystemStream.Input, SystemStream.Output, SystemStream.Error, or null if this terminal is not bound to a system stream
      See Also:
    • toString

      public String toString()
      Overrides:
      toString in class AbstractTerminal
    • getDefaultForegroundColor

      public int getDefaultForegroundColor()
      Description copied from class: AbstractTerminal
      Get the terminal's default foreground color. This method should be overridden by concrete implementations.
      Specified by:
      getDefaultForegroundColor in interface Terminal
      Overrides:
      getDefaultForegroundColor in class AbstractTerminal
      Returns:
      the RGB value of the default foreground color, or -1 if not available
      See Also:
    • getDefaultBackgroundColor

      public int getDefaultBackgroundColor()
      Description copied from class: AbstractTerminal
      Get the terminal's default background color. This method should be overridden by concrete implementations.
      Specified by:
      getDefaultBackgroundColor in interface Terminal
      Overrides:
      getDefaultBackgroundColor in class AbstractTerminal
      Returns:
      the RGB value of the default background color, or -1 if not available
      See Also: