Package org.jline.terminal.impl

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:

• AbstractTerminal
• Pty

Nested Class Summary

Nested classes/interfaces inherited from interface org.jline.terminal.Terminal

Terminal.MouseTracking, Terminal.Signal, Terminal.SignalHandler

Field Summary

Fields

Modifier and Type	Field	Description
protected final Attributes	originalAttributes
protected final Pty	pty

Fields inherited from class org.jline.terminal.impl.AbstractTerminal

bools, currentMouseTracking, encoding, handlers, ints, name, onClose, palette, status, strings, type

Fields inherited from interface org.jline.terminal.Terminal

TYPE_DUMB, TYPE_DUMB_COLOR

Constructor Summary

Constructors

Constructor	Description
AbstractPosixTerminal(String name, String type, Pty pty)
AbstractPosixTerminal(String name, String type, Pty pty, Charset encoding, Terminal.SignalHandler signalHandler)

Method Summary

Modifier and Type	Method	Description
protected void	doClose()
Attributes	getAttributes()	Returns the current terminal attributes.
Cursor	getCursorPosition(IntConsumer discarded)	Query the terminal to report the cursor position.
int	getDefaultBackgroundColor()	Get the terminal's default background color.
int	getDefaultForegroundColor()	Get the terminal's default foreground color.
TerminalProvider	getProvider()	Returns the terminal provider that created this terminal.
Pty	getPty()
Size	getSize()	Retrieve the size of the visible window
SystemStream	getSystemStream()	Returns the system stream associated with this terminal, if any.
void	setAttributes(Attributes attr)	Sets the terminal attributes to the specified values.
void	setSize(Size size)	Sets the size of the terminal.
String	toString()

Methods inherited from class org.jline.terminal.impl.AbstractTerminal

canPauseResume, checkInterrupted, close, echo, echo, echoSignal, encoding, enterRawMode, flush, getBooleanCapability, getCurrentMouseTracking, getKind, getName, getNumericCapability, getPalette, getStatus, getStatus, getStringCapability, getType, handle, hasFocusSupport, hasMouseSupport, parseInfoCmp, pause, pause, paused, puts, raise, readMouseEvent, readMouseEvent, readMouseEvent, readMouseEvent, resume, setOnClose, trackFocus, trackMouse

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.jline.terminal.Terminal

getBufferSize, getHeight, getWidth, input, output, reader, writer

Field Details

pty

protected final Pty pty

originalAttributes

protected final Attributes originalAttributes

Constructor Details

AbstractPosixTerminal

public AbstractPosixTerminal(String name,
 String type,
 Pty pty)
                      throws IOException

Throws:

IOException

AbstractPosixTerminal

public AbstractPosixTerminal(String name,
 String type,
 Pty pty,
 Charset encoding,
 Terminal.SignalHandler signalHandler)
                      throws IOException

Throws:

IOException

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:

• 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 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:

• 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

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:

• Terminal.getDefaultBackgroundColor()
• Terminal.getPalette()

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:

• Terminal.getDefaultForegroundColor()
• Terminal.getPalette()