Adding upstream version 3.8.1.upstream/3.8.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 742 insertions, 0 deletions

diff --git a/contrib/replxx/src/terminal.cxx b/contrib/replxx/src/terminal.cxx
new file mode 100644
index 0000000..e618219
--- /dev/null
+++ b/contrib/replxx/src/terminal.cxx
@@ -0,0 +1,742 @@
+#include <memory>
+#include <cerrno>
+#include <cstdlib>
+#include <cstring>
+#include <array>
+#include <stdexcept>
+
+#ifdef _WIN32
+
+#include <conio.h>
+#include <windows.h>
+#include <io.h>
+#define isatty _isatty
+#define strcasecmp _stricmp
+#define strdup _strdup
+#define write _write
+#define STDIN_FILENO 0
+
+#ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
+static DWORD const ENABLE_VIRTUAL_TERMINAL_PROCESSING = 4;
+#endif
+
+#include "windows.hxx"
+
+#else /* _WIN32 */
+
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/select.h>
+#include <fcntl.h>
+#include <signal.h>
+
+#endif /* _WIN32 */
+
+#include "terminal.hxx"
+#include "conversion.hxx"
+#include "escape.hxx"
+#include "replxx.hxx"
+#include "util.hxx"
+
+using namespace std;
+
+namespace replxx {
+
+namespace tty {
+
+bool is_a_tty( int fd_ ) {
+	bool aTTY( isatty( fd_ ) != 0 );
+#ifdef _WIN32
+	do {
+		if ( aTTY ) {
+			break;
+		}
+		HANDLE h( (HANDLE)_get_osfhandle( fd_ ) );
+		if ( h == INVALID_HANDLE_VALUE ) {
+			break;
+		}
+		DWORD st( 0 );
+		if ( ! GetConsoleMode( h, &st ) ) {
+			break;
+		}
+		aTTY = true;
+	} while ( false );
+#endif
+	return ( aTTY );
+}
+
+bool in( is_a_tty( 0 ) );
+bool out( is_a_tty( 1 ) );
+
+}
+
+#ifndef _WIN32
+Terminal* _terminal_ = nullptr;
+static void WindowSizeChanged( int ) {
+	if ( ! _terminal_ ) {
+		return;
+	}
+	_terminal_->notify_event( Terminal::EVENT_TYPE::RESIZE );
+}
+#endif
+
+
+Terminal::Terminal( void )
+#ifdef _WIN32
+	: _consoleOut( INVALID_HANDLE_VALUE )
+	, _consoleIn( INVALID_HANDLE_VALUE )
+	, _origOutMode()
+	, _origInMode()
+	, _oldDisplayAttribute()
+	, _inputCodePage( GetConsoleCP() )
+	, _outputCodePage( GetConsoleOutputCP() )
+	, _interrupt( INVALID_HANDLE_VALUE )
+	, _events()
+	, _empty()
+#else
+	: _origTermios()
+	, _interrupt()
+#endif
+	, _rawMode( false )
+	, _utf8() {
+#ifdef _WIN32
+	_interrupt = CreateEvent( nullptr, true, false, TEXT( "replxx_interrupt_event" ) );
+#else
+	static_cast<void>( ::pipe( _interrupt ) == 0 );
+#endif
+}
+
+Terminal::~Terminal( void ) {
+	if ( _rawMode ) {
+		disable_raw_mode();
+	}
+#ifdef _WIN32
+	CloseHandle( _interrupt );
+#else
+	static_cast<void>( ::close( _interrupt[0] ) == 0 );
+	static_cast<void>( ::close( _interrupt[1] ) == 0 );
+#endif
+}
+
+void Terminal::write32( char32_t const* text32, int len32 ) {
+	_utf8.assign( text32, len32 );
+	write8( _utf8.get(), _utf8.size() );
+	return;
+}
+
+void Terminal::write8( char const* data_, int size_ ) {
+#ifdef _WIN32
+	if ( ! _rawMode ) {
+		enable_out();
+	}
+	int nWritten( win_write( _consoleOut, _autoEscape, data_, size_ ) );
+	if ( ! _rawMode ) {
+		disable_out();
+	}
+#else
+	int nWritten( write( 1, data_, size_ ) );
+#endif
+	if ( nWritten != size_ ) {
+		throw std::runtime_error( "write failed" );
+	}
+	return;
+}
+
+int Terminal::get_screen_columns( void ) {
+	int cols( 0 );
+#ifdef _WIN32
+	CONSOLE_SCREEN_BUFFER_INFO inf;
+	GetConsoleScreenBufferInfo( _consoleOut, &inf );
+	cols = inf.dwSize.X;
+#else
+	struct winsize ws;
+	cols = ( ioctl( 1, TIOCGWINSZ, &ws ) == -1 ) ? 80 : ws.ws_col;
+#endif
+	// cols is 0 in certain circumstances like inside debugger, which creates
+	// further issues
+	return ( cols > 0 ) ? cols : 80;
+}
+
+int Terminal::get_screen_rows( void ) {
+	int rows;
+#ifdef _WIN32
+	CONSOLE_SCREEN_BUFFER_INFO inf;
+	GetConsoleScreenBufferInfo( _consoleOut, &inf );
+	rows = 1 + inf.srWindow.Bottom - inf.srWindow.Top;
+#else
+	struct winsize ws;
+	rows = (ioctl(1, TIOCGWINSZ, &ws) == -1) ? 24 : ws.ws_row;
+#endif
+	return (rows > 0) ? rows : 24;
+}
+
+namespace {
+inline int notty( void ) {
+	errno = ENOTTY;
+	return ( -1 );
+}
+}
+
+void Terminal::enable_out( void ) {
+#ifdef _WIN32
+	_consoleOut = GetStdHandle( STD_OUTPUT_HANDLE );
+	SetConsoleOutputCP( 65001 );
+	GetConsoleMode( _consoleOut, &_origOutMode );
+	_autoEscape = SetConsoleMode( _consoleOut, _origOutMode | ENABLE_VIRTUAL_TERMINAL_PROCESSING ) != 0;
+#endif
+}
+
+void Terminal::disable_out( void ) {
+#ifdef _WIN32
+	SetConsoleMode( _consoleOut, _origOutMode );
+	SetConsoleOutputCP( _outputCodePage );
+	_consoleOut = INVALID_HANDLE_VALUE;
+	_autoEscape = false;
+#endif
+}
+
+void Terminal::enable_bracketed_paste( void ) {
+	static char const  BRACK_PASTE_INIT[] = "\033[?2004h";
+	write8( BRACK_PASTE_INIT, sizeof ( BRACK_PASTE_INIT ) - 1 );
+}
+
+void Terminal::disable_bracketed_paste( void ) {
+	static char const  BRACK_PASTE_DISABLE[] = "\033[?2004l";
+	write8( BRACK_PASTE_DISABLE, sizeof ( BRACK_PASTE_DISABLE ) - 1 );
+}
+
+int Terminal::enable_raw_mode( void ) {
+	if ( ! _rawMode ) {
+#ifdef _WIN32
+		_consoleIn = GetStdHandle( STD_INPUT_HANDLE );
+		SetConsoleCP( 65001 );
+		GetConsoleMode( _consoleIn, &_origInMode );
+		SetConsoleMode(
+			_consoleIn,
+			_origInMode & ~( ENABLE_LINE_INPUT | ENABLE_ECHO_INPUT | ENABLE_PROCESSED_INPUT )
+		);
+		enable_out();
+#else
+		struct termios raw;
+
+		if ( ! tty::in ) {
+			return ( notty() );
+		}
+		if ( tcgetattr( 0, &_origTermios ) == -1 ) {
+			return ( notty() );
+		}
+
+		raw = _origTermios; /* modify the original mode */
+		/* input modes: no break, no CR to NL, no parity check, no strip char,
+		 * no start/stop output control. */
+		raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
+		/* output modes - disable post processing */
+		// this is wrong, we don't want raw output, it turns newlines into straight
+		// linefeeds
+		// raw.c_oflag &= ~(OPOST);
+		/* control modes - set 8 bit chars */
+		raw.c_cflag |= (CS8);
+		/* local modes - echoing off, canonical off, no extended functions,
+		 * no signal chars (^Z,^C) */
+		raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
+		/* control chars - set return condition: min number of bytes and timer.
+		 * We want read to return every single byte, without timeout. */
+		raw.c_cc[VMIN] = 1;
+		raw.c_cc[VTIME] = 0; /* 1 byte, no timer */
+
+		/* put terminal in raw mode after flushing */
+		if ( tcsetattr(0, TCSADRAIN, &raw) < 0 ) {
+			return ( notty() );
+		}
+		_terminal_ = this;
+#endif
+		_rawMode = true;
+	}
+	return ( 0 );
+}
+
+void Terminal::disable_raw_mode(void) {
+	if ( _rawMode ) {
+#ifdef _WIN32
+		disable_out();
+		SetConsoleMode( _consoleIn, _origInMode );
+		SetConsoleCP( _inputCodePage );
+		_consoleIn = INVALID_HANDLE_VALUE;
+#else
+		_terminal_ = nullptr;
+		if ( tcsetattr( 0, TCSADRAIN, &_origTermios ) == -1 ) {
+			return;
+		}
+#endif
+		_rawMode = false;
+	}
+}
+
+#ifndef _WIN32
+
+/**
+ * Read a UTF-8 sequence from the non-Windows keyboard and return the Unicode
+ * (char32_t) character it encodes
+ *
+ * @return char32_t Unicode character
+ */
+char32_t read_unicode_character(void) {
+	static char8_t utf8String[5];
+	static size_t utf8Count = 0;
+	while (true) {
+		char8_t c;
+
+		/* Continue reading if interrupted by signal. */
+		ssize_t nread;
+		do {
+			nread = read( STDIN_FILENO, &c, 1 );
+		} while ((nread == -1) && (errno == EINTR));
+
+		if (nread <= 0) return 0;
+		if (c <= 0x7F || locale::is8BitEncoding) { // short circuit ASCII
+			utf8Count = 0;
+			return c;
+		} else if (utf8Count < sizeof(utf8String) - 1) {
+			utf8String[utf8Count++] = c;
+			utf8String[utf8Count] = 0;
+			char32_t unicodeChar[2];
+			int ucharCount( 0 );
+			ConversionResult res = copyString8to32(unicodeChar, 2, ucharCount, utf8String);
+			if (res == conversionOK && ucharCount) {
+				utf8Count = 0;
+				return unicodeChar[0];
+			}
+		} else {
+			utf8Count = 0; // this shouldn't happen: got four bytes but no UTF-8 character
+		}
+	}
+}
+
+#endif // #ifndef _WIN32
+
+void beep() {
+	fprintf(stderr, "\x7");	// ctrl-G == bell/beep
+	fflush(stderr);
+}
+
+// replxx_read_char -- read a keystroke or keychord from the keyboard, and translate it
+// into an encoded "keystroke".	When convenient, extended keys are translated into their
+// simpler Emacs keystrokes, so an unmodified "left arrow" becomes Ctrl-B.
+//
+// A return value of zero means "no input available", and a return value of -1
+// means "invalid key".
+//
+char32_t Terminal::read_char( void ) {
+	char32_t c( 0 );
+#ifdef _WIN32
+	INPUT_RECORD rec;
+	DWORD count;
+	char32_t modifierKeys = 0;
+	bool escSeen = false;
+	int highSurrogate( 0 );
+	while (true) {
+		ReadConsoleInputW( _consoleIn, &rec, 1, &count );
+#if __REPLXX_DEBUG__	// helper for debugging keystrokes, display info in the debug "Output"
+		// window in the debugger
+		{
+			if ( rec.EventType == KEY_EVENT ) {
+				//if ( rec.Event.KeyEvent.uChar.UnicodeChar ) {
+				char buf[1024];
+				sprintf(
+					buf,
+					"Unicode character 0x%04X, repeat count %d, virtual keycode 0x%04X, "
+					"virtual scancode 0x%04X, key %s%s%s%s%s\n",
+					rec.Event.KeyEvent.uChar.UnicodeChar,
+					rec.Event.KeyEvent.wRepeatCount,
+					rec.Event.KeyEvent.wVirtualKeyCode,
+					rec.Event.KeyEvent.wVirtualScanCode,
+					rec.Event.KeyEvent.bKeyDown ? "down" : "up",
+					(rec.Event.KeyEvent.dwControlKeyState & LEFT_CTRL_PRESSED) ? " L-Ctrl" : "",
+					(rec.Event.KeyEvent.dwControlKeyState & RIGHT_CTRL_PRESSED) ? " R-Ctrl" : "",
+					(rec.Event.KeyEvent.dwControlKeyState & LEFT_ALT_PRESSED) ? " L-Alt" : "",
+					(rec.Event.KeyEvent.dwControlKeyState & RIGHT_ALT_PRESSED) ? " R-Alt" : ""
+				);
+				OutputDebugStringA( buf );
+				//}
+			}
+		}
+#endif
+		if ( rec.EventType != KEY_EVENT ) {
+			continue;
+		}
+		// Windows provides for entry of characters that are not on your keyboard by sending the
+		// Unicode characters as a "key up" with virtual keycode 0x12 (VK_MENU == Alt key) ...
+		// accept these characters, otherwise only process characters on "key down"
+		if ( !rec.Event.KeyEvent.bKeyDown && ( rec.Event.KeyEvent.wVirtualKeyCode != VK_MENU ) ) {
+			continue;
+		}
+		modifierKeys = 0;
+		// AltGr is encoded as ( LEFT_CTRL_PRESSED | RIGHT_ALT_PRESSED ), so don't treat this
+		// combination as either CTRL or META we just turn off those two bits, so it is still
+		// possible to combine CTRL and/or META with an AltGr key by using right-Ctrl and/or
+		// left-Alt
+		DWORD const AltGr( LEFT_CTRL_PRESSED | RIGHT_ALT_PRESSED );
+		if ( ( rec.Event.KeyEvent.dwControlKeyState & AltGr ) == AltGr ) {
+			rec.Event.KeyEvent.dwControlKeyState &= ~( LEFT_CTRL_PRESSED | RIGHT_ALT_PRESSED );
+		}
+		if ( rec.Event.KeyEvent.dwControlKeyState & ( RIGHT_CTRL_PRESSED | LEFT_CTRL_PRESSED ) ) {
+			modifierKeys |= Replxx::KEY::BASE_CONTROL;
+		}
+		if ( rec.Event.KeyEvent.dwControlKeyState & ( RIGHT_ALT_PRESSED | LEFT_ALT_PRESSED ) ) {
+			modifierKeys |= Replxx::KEY::BASE_META;
+		}
+		if ( escSeen ) {
+			modifierKeys |= Replxx::KEY::BASE_META;
+		}
+		int key( rec.Event.KeyEvent.uChar.UnicodeChar );
+		if ( key == 0 ) {
+			switch (rec.Event.KeyEvent.wVirtualKeyCode) {
+				case VK_LEFT:
+					return modifierKeys | Replxx::KEY::LEFT;
+				case VK_RIGHT:
+					return modifierKeys | Replxx::KEY::RIGHT;
+				case VK_UP:
+					return modifierKeys | Replxx::KEY::UP;
+				case VK_DOWN:
+					return modifierKeys | Replxx::KEY::DOWN;
+				case VK_DELETE:
+					return modifierKeys | Replxx::KEY::DELETE;
+				case VK_HOME:
+					return modifierKeys | Replxx::KEY::HOME;
+				case VK_END:
+					return modifierKeys | Replxx::KEY::END;
+				case VK_PRIOR:
+					return modifierKeys | Replxx::KEY::PAGE_UP;
+				case VK_NEXT:
+					return modifierKeys | Replxx::KEY::PAGE_DOWN;
+				case VK_F1:
+					return modifierKeys | Replxx::KEY::F1;
+				case VK_F2:
+					return modifierKeys | Replxx::KEY::F2;
+				case VK_F3:
+					return modifierKeys | Replxx::KEY::F3;
+				case VK_F4:
+					return modifierKeys | Replxx::KEY::F4;
+				case VK_F5:
+					return modifierKeys | Replxx::KEY::F5;
+				case VK_F6:
+					return modifierKeys | Replxx::KEY::F6;
+				case VK_F7:
+					return modifierKeys | Replxx::KEY::F7;
+				case VK_F8:
+					return modifierKeys | Replxx::KEY::F8;
+				case VK_F9:
+					return modifierKeys | Replxx::KEY::F9;
+				case VK_F10:
+					return modifierKeys | Replxx::KEY::F10;
+				case VK_F11:
+					return modifierKeys | Replxx::KEY::F11;
+				case VK_F12:
+					return modifierKeys | Replxx::KEY::F12;
+				default:
+					continue; // in raw mode, ReadConsoleInput shows shift, ctrl - ignore them
+			}
+		} else if ( key == Replxx::KEY::ESCAPE ) { // ESC, set flag for later
+			escSeen = true;
+			continue;
+		} else if ( ( key >= 0xD800 ) && ( key <= 0xDBFF ) ) {
+			highSurrogate = key - 0xD800;
+			continue;
+		} else {
+			// we got a real character, return it
+			if ( ( key >= 0xDC00 ) && ( key <= 0xDFFF ) ) {
+				key -= 0xDC00;
+				key |= ( highSurrogate << 10 );
+				key += 0x10000;
+			}
+			if ( is_control_code( key ) ) {
+				key = control_to_human( key );
+				modifierKeys |= Replxx::KEY::BASE_CONTROL;
+			}
+			key |= modifierKeys;
+			highSurrogate = 0;
+			c = key;
+			break;
+		}
+	}
+
+#else
+	c = read_unicode_character();
+	if (c == 0) {
+		return 0;
+	}
+
+// If _DEBUG_LINUX_KEYBOARD is set, then ctrl-^ puts us into a keyboard
+// debugging mode
+// where we print out decimal and decoded values for whatever the "terminal"
+// program
+// gives us on different keystrokes.	Hit ctrl-C to exit this mode.
+//
+#ifdef __REPLXX_DEBUG__
+	if (c == ctrlChar('^')) {	// ctrl-^, special debug mode, prints all keys hit,
+														 // ctrl-C to get out
+		printf(
+				"\nEntering keyboard debugging mode (on ctrl-^), press ctrl-C to exit "
+				"this mode\n");
+		while (true) {
+			unsigned char keys[10];
+			int ret = read(0, keys, 10);
+
+			if (ret <= 0) {
+				printf("\nret: %d\n", ret);
+			}
+			for (int i = 0; i < ret; ++i) {
+				char32_t key = static_cast<char32_t>(keys[i]);
+				char* friendlyTextPtr;
+				char friendlyTextBuf[10];
+				const char* prefixText = (key < 0x80) ? "" : "0x80+";
+				char32_t keyCopy = (key < 0x80) ? key : key - 0x80;
+				if (keyCopy >= '!' && keyCopy <= '~') {	// printable
+					friendlyTextBuf[0] = '\'';
+					friendlyTextBuf[1] = keyCopy;
+					friendlyTextBuf[2] = '\'';
+					friendlyTextBuf[3] = 0;
+					friendlyTextPtr = friendlyTextBuf;
+				} else if (keyCopy == ' ') {
+					friendlyTextPtr = const_cast<char*>("space");
+				} else if (keyCopy == 27) {
+					friendlyTextPtr = const_cast<char*>("ESC");
+				} else if (keyCopy == 0) {
+					friendlyTextPtr = const_cast<char*>("NUL");
+				} else if (keyCopy == 127) {
+					friendlyTextPtr = const_cast<char*>("DEL");
+				} else {
+					friendlyTextBuf[0] = '^';
+					friendlyTextBuf[1] = control_to_human( keyCopy );
+					friendlyTextBuf[2] = 0;
+					friendlyTextPtr = friendlyTextBuf;
+				}
+				printf("%d x%02X (%s%s)	", key, key, prefixText, friendlyTextPtr);
+			}
+			printf("\x1b[1G\n");	// go to first column of new line
+
+			// drop out of this loop on ctrl-C
+			if (keys[0] == ctrlChar('C')) {
+				printf("Leaving keyboard debugging mode (on ctrl-C)\n");
+				fflush(stdout);
+				return -2;
+			}
+		}
+	}
+#endif // __REPLXX_DEBUG__
+
+	c = EscapeSequenceProcessing::doDispatch(c);
+	if ( is_control_code( c ) ) {
+		c = Replxx::KEY::control( control_to_human( c ) );
+	}
+#endif // #_WIN32
+	return ( c );
+}
+
+Terminal::EVENT_TYPE Terminal::wait_for_input( int long timeout_ ) {
+#ifdef _WIN32
+	std::array<HANDLE,2> handles = { _consoleIn, _interrupt };
+	while ( true ) {
+		DWORD event( WaitForMultipleObjects( static_cast<DWORD>( handles.size() ), handles.data(), false, timeout_ > 0 ? timeout_ : INFINITE ) );
+		switch ( event ) {
+			case ( WAIT_OBJECT_0 + 0 ): {
+				// peek events that will be skipped
+				INPUT_RECORD rec;
+				DWORD count;
+				PeekConsoleInputW( _consoleIn, &rec, 1, &count );
+
+				if (
+					( rec.EventType != KEY_EVENT )
+					|| ( !rec.Event.KeyEvent.bKeyDown && ( rec.Event.KeyEvent.wVirtualKeyCode != VK_MENU ) )
+				) {
+					// read the event to unsignal the handle
+					ReadConsoleInputW( _consoleIn, &rec, 1, &count );
+					continue;
+				} else if (rec.EventType == KEY_EVENT) {
+					int key(rec.Event.KeyEvent.uChar.UnicodeChar);
+					if (key == 0) {
+						switch (rec.Event.KeyEvent.wVirtualKeyCode) {
+						case VK_LEFT:
+						case VK_RIGHT:
+						case VK_UP:
+						case VK_DOWN:
+						case VK_DELETE:
+						case VK_HOME:
+						case VK_END:
+						case VK_PRIOR:
+						case VK_NEXT:
+							break;
+						default:
+							ReadConsoleInputW(_consoleIn, &rec, 1, &count);
+							continue; // in raw mode, ReadConsoleInput shows shift, ctrl - ignore them
+						}
+					}
+				}
+
+				return ( EVENT_TYPE::KEY_PRESS );
+			}
+			case ( WAIT_OBJECT_0 + 1 ): {
+				ResetEvent( _interrupt );
+				if ( _events.empty() ) {
+					continue;
+				}
+				EVENT_TYPE eventType( _events.front() );
+				_events.pop_front();
+				return ( eventType );
+			}
+			case ( WAIT_TIMEOUT ): {
+				return ( EVENT_TYPE::TIMEOUT );
+			}
+		}
+	}
+#else
+	fd_set fdSet;
+	int nfds( max( _interrupt[0], _interrupt[1] ) + 1 );
+	while ( true ) {
+		FD_ZERO( &fdSet );
+		FD_SET( 0, &fdSet );
+		FD_SET( _interrupt[0], &fdSet );
+		timeval tv{ timeout_ / 1000, static_cast<suseconds_t>( ( timeout_ % 1000 ) * 1000 ) };
+		int err( select( nfds, &fdSet, nullptr, nullptr, timeout_ > 0 ? &tv : nullptr ) );
+		if ( ( err == -1 ) && ( errno == EINTR ) ) {
+			continue;
+		}
+		if ( err == 0 ) {
+			return ( EVENT_TYPE::TIMEOUT );
+		}
+		if ( FD_ISSET( _interrupt[0], &fdSet ) ) {
+			char data( 0 );
+			static_cast<void>( read( _interrupt[0], &data, 1 ) == 1 );
+			if ( data == 'k' ) {
+				return ( EVENT_TYPE::KEY_PRESS );
+			}
+			if ( data == 'm' ) {
+				return ( EVENT_TYPE::MESSAGE );
+			}
+			if ( data == 'r' ) {
+				return ( EVENT_TYPE::RESIZE );
+			}
+		}
+		if ( FD_ISSET( 0, &fdSet ) ) {
+			return ( EVENT_TYPE::KEY_PRESS );
+		}
+	}
+#endif
+}
+
+void Terminal::notify_event( EVENT_TYPE eventType_ ) {
+#ifdef _WIN32
+	_events.push_back( eventType_ );
+	SetEvent( _interrupt );
+#else
+	char data( ( eventType_ == EVENT_TYPE::KEY_PRESS ) ? 'k' : ( eventType_ == EVENT_TYPE::MESSAGE ? 'm' : 'r' ) );
+	static_cast<void>( write( _interrupt[1], &data, 1 ) == 1 );
+#endif
+}
+
+/**
+ * Clear the screen ONLY (no redisplay of anything)
+ */
+void Terminal::clear_screen( CLEAR_SCREEN clearScreen_ ) {
+#ifdef _WIN32
+	if ( _autoEscape ) {
+#endif
+		if ( clearScreen_ == CLEAR_SCREEN::WHOLE ) {
+			char const clearCode[] = "\033c\033[H\033[2J\033[0m";
+			static_cast<void>( write(1, clearCode, sizeof ( clearCode ) - 1) >= 0 );
+		} else {
+			char const clearCode[] = "\033[J";
+			static_cast<void>( write(1, clearCode, sizeof ( clearCode ) - 1) >= 0 );
+		}
+		return;
+#ifdef _WIN32
+	}
+	COORD coord = { 0, 0 };
+	CONSOLE_SCREEN_BUFFER_INFO inf;
+	HANDLE consoleOut( _consoleOut != INVALID_HANDLE_VALUE ? _consoleOut : GetStdHandle( STD_OUTPUT_HANDLE ) );
+	GetConsoleScreenBufferInfo( consoleOut, &inf );
+	if ( clearScreen_ == CLEAR_SCREEN::TO_END ) {
+		coord = inf.dwCursorPosition;
+		DWORD nWritten( 0 );
+		SHORT height( inf.srWindow.Bottom - inf.srWindow.Top );
+		DWORD yPos( inf.dwCursorPosition.Y - inf.srWindow.Top );
+		DWORD toWrite( ( height + 1 - yPos ) * inf.dwSize.X - inf.dwCursorPosition.X );
+//		FillConsoleOutputCharacterA( consoleOut, ' ', toWrite, coord, &nWritten );
+		_empty.resize( toWrite - 1, ' ' );
+		WriteConsoleA( consoleOut, _empty.data(), toWrite - 1, &nWritten, nullptr );
+	} else {
+		COORD scrollTarget = { 0, -inf.dwSize.Y };
+		CHAR_INFO fill{ TEXT( ' ' ), inf.wAttributes };
+		SMALL_RECT scrollRect = { 0, 0, inf.dwSize.X, inf.dwSize.Y };
+		ScrollConsoleScreenBuffer( consoleOut, &scrollRect, nullptr, scrollTarget, &fill );
+	}
+	SetConsoleCursorPosition( consoleOut, coord );
+#endif
+}
+
+void Terminal::jump_cursor( int xPos_, int yOffset_ ) {
+#ifdef _WIN32
+	CONSOLE_SCREEN_BUFFER_INFO inf;
+	GetConsoleScreenBufferInfo( _consoleOut, &inf );
+	inf.dwCursorPosition.X = xPos_;
+	inf.dwCursorPosition.Y += yOffset_;
+	SetConsoleCursorPosition( _consoleOut, inf.dwCursorPosition );
+#else
+	char seq[64];
+	if ( yOffset_ != 0 ) { // move the cursor up as required
+		snprintf( seq, sizeof seq, "\033[%d%c", abs( yOffset_ ), yOffset_ > 0 ? 'B' : 'A' );
+		write8( seq, strlen( seq ) );
+	}
+	// position at the end of the prompt, clear to end of screen
+	snprintf(
+		seq, sizeof seq, "\033[%dG",
+		xPos_ + 1 /* 1-based on VT100 */
+	);
+	write8( seq, strlen( seq ) );
+#endif
+}
+
+#ifdef _WIN32
+void Terminal::set_cursor_visible( bool visible_ ) {
+	CONSOLE_CURSOR_INFO     cursorInfo;
+	GetConsoleCursorInfo( _consoleOut, &cursorInfo );
+	cursorInfo.bVisible = visible_;
+	SetConsoleCursorInfo( _consoleOut, &cursorInfo );
+	return;
+}
+#else
+void Terminal::set_cursor_visible( bool ) {}
+#endif
+
+#ifndef _WIN32
+int Terminal::read_verbatim( char32_t* buffer_, int size_ ) {
+	int len( 0 );
+	buffer_[len ++] = read_unicode_character();
+	int statusFlags( ::fcntl( STDIN_FILENO, F_GETFL, 0 ) );
+	::fcntl( STDIN_FILENO, F_SETFL, statusFlags | O_NONBLOCK );
+	while ( len < size_ ) {
+		char32_t c( read_unicode_character() );
+		if ( c == 0 ) {
+			break;
+		}
+		buffer_[len ++] = c;
+	}
+	::fcntl( STDIN_FILENO, F_SETFL, statusFlags );
+	return ( len );
+}
+
+int Terminal::install_window_change_handler( void ) {
+	struct sigaction sa;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = 0;
+	sa.sa_handler = &WindowSizeChanged;
+
+	if (sigaction(SIGWINCH, &sa, nullptr) == -1) {
+		return errno;
+	}
+	return 0;
+}
+#endif
+
+}
+