Class AbstractPosixTerminal

  • All Implemented Interfaces:
    java.io.Closeable, java.io.Flushable, java.lang.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:
    AbstractTerminal, Pty
    • Field Detail

      • pty

        protected final Pty pty
      • originalAttributes

        protected final Attributes originalAttributes
    • Constructor Detail

      • AbstractPosixTerminal

        public AbstractPosixTerminal​(java.lang.String name,
                                     java.lang.String type,
                                     Pty pty)
                              throws java.io.IOException
        Throws:
        java.io.IOException
      • AbstractPosixTerminal

        public AbstractPosixTerminal​(java.lang.String name,
                                     java.lang.String type,
                                     Pty pty,
                                     java.nio.charset.Charset encoding,
                                     Terminal.SignalHandler signalHandler)
                              throws java.io.IOException
        Throws:
        java.io.IOException
      • AbstractPosixTerminal

        public AbstractPosixTerminal​(java.lang.String name,
                                     java.lang.String type,
                                     Pty pty,
                                     java.nio.charset.Charset encoding,
                                     java.nio.charset.Charset stdinEncoding,
                                     java.nio.charset.Charset stdoutEncoding,
                                     java.nio.charset.Charset stderrEncoding,
                                     Terminal.SignalHandler signalHandler)
                              throws java.io.IOException
        Throws:
        java.io.IOException
    • Method Detail

      • 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:
        Terminal.setAttributes(Attributes), Attributes, Terminal.enterRawMode()
      • 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:
        Terminal.getAttributes(), Attributes, Terminal.enterRawMode()
      • getSize

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

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

        public Cursor getCursorPosition​(java.util.function.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:
        TerminalProvider
      • 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:
        SystemStream