// Tab across to the next stop, or perform tab completion.
private void Tab()
{
if (TabComplete == null)
{
// Add the TAB character and repaint the line.
AddChar('\t');
}
else
{
if (_state != ReadlineState.Completing)
{
CollectLastWord('\0');
_state = ReadlineState.Completing;
}
// Perform tab completion and insert the results.
var e = new TabCompleteEventArgs(_lastWord.ToString(), ++_tabCount);
TabComplete(this, e);
if (e.Insert != null)
{
_savePosn = _posn;
// Insert the value that we found.
var saveOverwrite = _overwrite;
_overwrite = false;
_savePosn = e.Insert.Length;
_state = ReadlineState.Completing;
foreach (var ch in e.Insert)
{
AddChar(ch);
}
_overwrite = saveOverwrite;
}
else if (e.Alternatives != null && e.Alternatives.Length > 0)
{
// Print the alternatives for the user.
_savePosn = _posn;
EndLine();
PrintAlternatives?.Invoke(this, new PrintAlternativesEventArgs(e.Alternatives));
WritePrompt?.Invoke(this, EventArgs.Empty);
_posn = _savePosn;
_state = ReadlineState.Completing;
Redraw();
}
else
{
if (e.Error)
{
ResetComplete(ReadlineState.MoreInput);
}
// No alternatives, or alternatives not supplied yet.
Console.Beep();
}
}
}
private void ResetComplete(ReadlineState newState)
{
if (_state == ReadlineState.Completing)
{
_tabCount = -1;
_savePosn = -1;
}
_state = newState;
}
// Read the next line of input using line editing. Returns "null"
// if an EOF indication is encountered in the input.
public string ReadLine()
{
var treatControlCAsInterrupt = Console.TreatControlCAsInput;
Console.TreatControlCAsInput = !CtrlCInterrupts;
try
{
// Output the prompt.
WritePrompt?.Invoke(this, EventArgs.Empty);
// Enter the main character input loop.
_posn = 0;
_length = 0;
_column = 0;
_lastColumn = 0;
_overwrite = false;
_historyPosn = -1;
var ctrlv = false;
_state = ReadlineState.MoreInput;
do
{
var key = ConsoleExtensions.ReadKey(true);
var ch = key.KeyChar;
if (ctrlv)
{
ctrlv = false;
if ((ch >= 0x0001 && ch <= 0x001F) || ch == 0x007F)
{
// Insert a control character into the buffer.
AddChar(ch);
continue;
}
}
if (ch != '\0')
{
switch (ch)
{
case '\u0001':
{
// CTRL-A: move to the home position.
MoveHome();
}
break;
case '\u0002':
{
// CTRL-B: go back one character.
MoveLeft();
}
break;
case '\u0003':
{
// CTRL-C encountered in "raw" mode.
if (CtrlCInterrupts)
{
EndLine();
Interrupt?.Invoke(null, EventArgs.Empty);
return(null);
}
CancelLine();
_lastWord.Length = 0;
}
break;
case '\u0004':
{
// CTRL-D: EOF or delete the current character.
if (CtrlDIsEOF)
{
_lastWord.Length = 0;
// Signal an EOF if the buffer is empty.
if (_length == 0)
{
EndLine();
return(null);
}
}
else
{
Delete();
ResetComplete(ReadlineState.MoreInput);
}
}
break;
case '\u0005':
{
// CTRL-E: move to the end position.
MoveEnd();
}
break;
case '\u0006':
{
// CTRL-F: go forward one character.
MoveRight();
}
break;
case '\u0007':
{
// CTRL-G: ring the terminal bell.
Console.Beep();
}
break;
case '\u0008':
case '\u007F':
{
if (key.Key == ConsoleKey.Delete)
{
// Delete the character under the cursor.
Delete();
}
else
{
// Delete the character before the cursor.
Backspace();
}
ResetComplete(ReadlineState.MoreInput);
}
break;
case '\u0009':
{
// Process a tab.
Tab();
}
break;
case '\u000A':
case '\u000D':
{
// Line termination.
EndLine();
ResetComplete(ReadlineState.Done);
_lastWord.Length = 0;
}
break;
case '\u000B':
{
// CTRL-K: erase until the end of the line.
EraseToEnd();
}
break;
case '\u000C':
{
// CTRL-L: clear screen and redraw.
Console.Clear();
WritePrompt?.Invoke(this, EventArgs.Empty);
Redraw();
}
break;
case '\u000E':
{
// CTRL-N: move down in the history.
MoveDown();
}
break;
case '\u0010':
{
// CTRL-P: move up in the history.
MoveUp();
}
break;
case '\u0015':
{
// CTRL-U: erase to the start of the line.
EraseToStart();
ResetComplete(ReadlineState.None);
}
break;
case '\u0016':
{
// CTRL-V: prefix a control character.
ctrlv = true;
}
break;
case '\u0017':
{
// CTRL-W: erase the previous word.
EraseWord();
ResetComplete(ReadlineState.MoreInput);
}
break;
case '\u0019':
{
// CTRL-Y: yank the last erased string.
if (_yankedString != null)
{
foreach (var ch2 in _yankedString)
{
AddChar(ch2);
}
}
}
break;
case '\u001A':
{
// CTRL-Z: Windows end of file indication.
if (CtrlZIsEOF && _length == 0)
{
EndLine();
return(null);
}
}
break;
case '\u001B':
{
// Escape is "clear line".
Clear();
ResetComplete(ReadlineState.MoreInput);
}
break;
default:
{
if (ch >= ' ')
{
// Ordinary character.
AddChar(ch);
ResetComplete(ReadlineState.MoreInput);
}
}
break;
}
}
else if (key.Modifiers == 0)
{
switch (key.Key)
{
case ConsoleKey.Backspace:
{
// Delete the character before the cursor.
Backspace();
ResetComplete(ReadlineState.MoreInput);
}
break;
case ConsoleKey.Delete:
{
// Delete the character under the cursor.
Delete();
ResetComplete(ReadlineState.MoreInput);
}
break;
case ConsoleKey.Enter:
{
// Line termination.
EndLine();
ResetComplete(ReadlineState.Done);
}
break;
case ConsoleKey.Escape:
{
// Clear the current line.
Clear();
ResetComplete(ReadlineState.None);
}
break;
case ConsoleKey.Tab:
{
// Process a tab.
Tab();
}
break;
case ConsoleKey.LeftArrow:
{
// Move left one character.
MoveLeft();
}
break;
case ConsoleKey.RightArrow:
{
// Move right one character.
MoveRight();
}
break;
case ConsoleKey.UpArrow:
{
// Move up one line in the history.
MoveUp();
}
break;
case ConsoleKey.DownArrow:
{
// Move down one line in the history.
MoveDown();
}
break;
case ConsoleKey.Home:
{
// Move to the beginning of the line.
MoveHome();
}
break;
case ConsoleKey.End:
{
// Move to the end of the line.
MoveEnd();
}
break;
case ConsoleKey.Insert:
{
// Toggle insert/overwrite mode.
_overwrite = !_overwrite;
}
break;
}
}
else if ((key.Modifiers & ConsoleModifiers.Alt) != 0)
{
switch (key.Key)
{
case ConsoleKey.F:
{
// ALT-F: move forward a word.
MoveForwardWord();
}
break;
case ConsoleKey.B:
{
// ALT-B: move backward a word.
MoveBackwardWord();
}
break;
case ConsoleKey.D:
{
// ALT-D: erase until the end of the word.
EraseToEndWord();
}
break;
case ConsoleKey.Backspace:
case ConsoleKey.Delete:
{
// ALT-DEL: erase until the start of the word.
EraseToStartWord();
}
break;
}
}
} while (_state != ReadlineState.Done);
return(new string(_buffer, 0, _length));
}
finally
{
Console.TreatControlCAsInput = treatControlCAsInterrupt;
}
}
// Read the next line of input using line editing. Returns "null"
// if an EOF indication is encountered in the input.
public string ReadLine()
{
var treatControlCAsInterrupt = Console.TreatControlCAsInput;
Console.TreatControlCAsInput = !CtrlCInterrupts;
try
{
// Output the prompt.
WritePrompt?.Invoke(this, EventArgs.Empty);
// Enter the main character input loop.
_posn = 0;
_length = 0;
_column = 0;
_lastColumn = 0;
_overwrite = false;
_historyPosn = -1;
var ctrlv = false;
_state = ReadlineState.MoreInput;
do
{
var key = ConsoleExtensions.ReadKey(true);
var ch = key.KeyChar;
if (ctrlv)
{
ctrlv = false;
if ((ch >= 0x0001 && ch <= 0x001F) || ch == 0x007F)
{
// Insert a control character into the buffer.
AddChar(ch);
continue;
}
}
if (ch != '\0')
{
switch (ch)
{
case '\u0001':
{
// CTRL-A: move to the home position.
MoveHome();
}
break;
case '\u0002':
{
// CTRL-B: go back one character.
MoveLeft();
}
break;
case '\u0003':
{
// CTRL-C encountered in "raw" mode.
if (CtrlCInterrupts)
{
EndLine();
Interrupt?.Invoke(null, EventArgs.Empty);
return null;
}
CancelLine();
_lastWord.Length = 0;
}
break;
case '\u0004':
{
// CTRL-D: EOF or delete the current character.
if (CtrlDIsEOF)
{
_lastWord.Length = 0;
// Signal an EOF if the buffer is empty.
if (_length == 0)
{
EndLine();
return null;
}
}
else
{
Delete();
ResetComplete(ReadlineState.MoreInput);
}
}
break;
case '\u0005':
{
// CTRL-E: move to the end position.
MoveEnd();
}
break;
case '\u0006':
{
// CTRL-F: go forward one character.
MoveRight();
}
break;
case '\u0007':
{
// CTRL-G: ring the terminal bell.
Console.Beep();
}
break;
case '\u0008':
case '\u007F':
{
if (key.Key == ConsoleKey.Delete)
{
// Delete the character under the cursor.
Delete();
}
else
{
// Delete the character before the cursor.
Backspace();
}
ResetComplete(ReadlineState.MoreInput);
}
break;
case '\u0009':
{
// Process a tab.
Tab();
}
break;
case '\u000A':
case '\u000D':
{
// Line termination.
EndLine();
ResetComplete(ReadlineState.Done);
_lastWord.Length = 0;
}
break;
case '\u000B':
{
// CTRL-K: erase until the end of the line.
EraseToEnd();
}
break;
case '\u000C':
{
// CTRL-L: clear screen and redraw.
Console.Clear();
WritePrompt?.Invoke(this, EventArgs.Empty);
Redraw();
}
break;
case '\u000E':
{
// CTRL-N: move down in the history.
MoveDown();
}
break;
case '\u0010':
{
// CTRL-P: move up in the history.
MoveUp();
}
break;
case '\u0015':
{
// CTRL-U: erase to the start of the line.
EraseToStart();
ResetComplete(ReadlineState.None);
}
break;
case '\u0016':
{
// CTRL-V: prefix a control character.
ctrlv = true;
}
break;
case '\u0017':
{
// CTRL-W: erase the previous word.
EraseWord();
ResetComplete(ReadlineState.MoreInput);
}
break;
case '\u0019':
{
// CTRL-Y: yank the last erased string.
if (_yankedString != null)
{
foreach (var ch2 in _yankedString)
{
AddChar(ch2);
}
}
}
break;
case '\u001A':
{
// CTRL-Z: Windows end of file indication.
if (CtrlZIsEOF && _length == 0)
{
EndLine();
return null;
}
}
break;
case '\u001B':
{
// Escape is "clear line".
Clear();
ResetComplete(ReadlineState.MoreInput);
}
break;
default:
{
if (ch >= ' ')
{
// Ordinary character.
AddChar(ch);
ResetComplete(ReadlineState.MoreInput);
}
}
break;
}
}
else if (key.Modifiers == 0)
{
switch (key.Key)
{
case ConsoleKey.Backspace:
{
// Delete the character before the cursor.
Backspace();
ResetComplete(ReadlineState.MoreInput);
}
break;
case ConsoleKey.Delete:
{
// Delete the character under the cursor.
Delete();
ResetComplete(ReadlineState.MoreInput);
}
break;
case ConsoleKey.Enter:
{
// Line termination.
EndLine();
ResetComplete(ReadlineState.Done);
}
break;
case ConsoleKey.Escape:
{
// Clear the current line.
Clear();
ResetComplete(ReadlineState.None);
}
break;
case ConsoleKey.Tab:
{
// Process a tab.
Tab();
}
break;
case ConsoleKey.LeftArrow:
{
// Move left one character.
MoveLeft();
}
break;
case ConsoleKey.RightArrow:
{
// Move right one character.
MoveRight();
}
break;
case ConsoleKey.UpArrow:
{
// Move up one line in the history.
MoveUp();
}
break;
case ConsoleKey.DownArrow:
{
// Move down one line in the history.
MoveDown();
}
break;
case ConsoleKey.Home:
{
// Move to the beginning of the line.
MoveHome();
}
break;
case ConsoleKey.End:
{
// Move to the end of the line.
MoveEnd();
}
break;
case ConsoleKey.Insert:
{
// Toggle insert/overwrite mode.
_overwrite = !_overwrite;
}
break;
}
}
else if ((key.Modifiers & ConsoleModifiers.Alt) != 0)
{
switch (key.Key)
{
case ConsoleKey.F:
{
// ALT-F: move forward a word.
MoveForwardWord();
}
break;
case ConsoleKey.B:
{
// ALT-B: move backward a word.
MoveBackwardWord();
}
break;
case ConsoleKey.D:
{
// ALT-D: erase until the end of the word.
EraseToEndWord();
}
break;
case ConsoleKey.Backspace:
case ConsoleKey.Delete:
{
// ALT-DEL: erase until the start of the word.
EraseToStartWord();
}
break;
}
}
} while (_state != ReadlineState.Done);
return new string(_buffer, 0, _length);
}
finally
{
Console.TreatControlCAsInput = treatControlCAsInterrupt;
}
}
// Tab across to the next stop, or perform tab completion.
private void Tab()
{
if (TabComplete == null)
{
// Add the TAB character and repaint the line.
AddChar('\t');
}
else
{
if (_state != ReadlineState.Completing)
{
CollectLastWord('\0');
_state = ReadlineState.Completing;
}
// Perform tab completion and insert the results.
var e = new TabCompleteEventArgs(_lastWord.ToString(), ++_tabCount);
TabComplete(this, e);
if (e.Insert != null)
{
_savePosn = _posn;
// Insert the value that we found.
var saveOverwrite = _overwrite;
_overwrite = false;
_savePosn = e.Insert.Length;
_state = ReadlineState.Completing;
foreach (var ch in e.Insert)
{
AddChar(ch);
}
_overwrite = saveOverwrite;
}
else if (e.Alternatives != null && e.Alternatives.Length > 0)
{
// Print the alternatives for the user.
_savePosn = _posn;
EndLine();
PrintAlternatives?.Invoke(this, new PrintAlternativesEventArgs(e.Alternatives));
WritePrompt?.Invoke(this, EventArgs.Empty);
_posn = _savePosn;
_state = ReadlineState.Completing;
Redraw();
}
else
{
if (e.Error)
{
ResetComplete(ReadlineState.MoreInput);
}
// No alternatives, or alternatives not supplied yet.
Console.Beep();
}
}
}
private void ResetComplete(ReadlineState newState)
{
if (_state == ReadlineState.Completing)
{
_tabCount = -1;
_savePosn = -1;
}
_state = newState;
}
