term: obtain the cursor position via termios.h (#11372)

vlib/os/os.c.v

@@ -1008,3 +1008,15 @@ pub fn glob(patterns ...string) ?[]string {
 	matches.sort()
 	return matches
 }
+
+pub fn last_error() IError {
+	$if windows {
+		code := int(C.GetLastError())
+		msg := get_error_msg(code)
+		return error_with_code(msg, code)
+	} $else {
+		code := C.errno
+		msg := posix_get_error_msg(code)
+		return error_with_code(msg, code)
+	}
+}

vlib/readline/readline.v

@@ -7,18 +7,6 @@
 //
 module readline
 
-// Termios stores the terminal options on Linux.
-struct C.termios {}
-
-struct Termios {
-mut:
-	c_iflag int
-	c_oflag int
-	c_cflag int
-	c_lflag int
-	c_cc    [12]int // NCCS == 12. Can't use the defined value here
-}
-
 // Winsize stores the screen information on Linux.
 struct Winsize {
 	ws_row    u16

vlib/readline/readline_default.c.v

@@ -10,7 +10,9 @@ module readline
 
 import os
 
-#include <termios.h>
+struct Termios {
+}
+
 // Only use standard os.get_line
 // Need implementation for readline capabilities
 //

vlib/readline/readline_linux.c.v

@@ -13,9 +13,32 @@ import os
 #include <termios.h>
 #include <sys/ioctl.h>
 
+const cclen = 10
+
+// Termios stores the terminal options on Linux.
+struct C.termios {
+mut:
+	c_iflag int
+	c_oflag int
+	c_cflag int
+	c_lflag int
+	c_line  byte
+	c_cc    [cclen]int
+}
+
+struct Termios {
+mut:
+	c_iflag u32
+	c_oflag u32
+	c_cflag u32
+	c_lflag u32
+	c_line  byte
+	c_cc    [cclen]int
+}
+
 fn C.tcgetattr(fd int, termios_p &C.termios) int
 
-fn C.tcsetattr(fd int, optional_actions int, termios_p &C.termios) int
+fn C.tcsetattr(fd int, optional_actions int, const_termios_p &C.termios) int
 
 fn C.raise(sig int)
 
@@ -47,18 +70,22 @@ enum Action {
 // Please note that `enable_raw_mode` catches the `SIGUSER` (CTRL + C) signal.
 // For a method that does please see `enable_raw_mode_nosig`.
 pub fn (mut r Readline) enable_raw_mode() {
-	if C.tcgetattr(0, unsafe { &C.termios(&r.orig_termios) }) == -1 {
+	if unsafe { C.tcgetattr(0, &C.termios(&r.orig_termios)) } != 0 {
 		r.is_tty = false
 		r.is_raw = false
 		return
 	}
-	mut raw := r.orig_termios
+	mut raw := C.termios{}
+	unsafe { vmemcpy(&raw, &r.orig_termios, int(sizeof(raw))) }
+	// println('> r.orig_termios: $r.orig_termios')
+	// println('>            raw: $raw')
 	raw.c_iflag &= ~(C.BRKINT | C.ICRNL | C.INPCK | C.ISTRIP | C.IXON)
 	raw.c_cflag |= C.CS8
 	raw.c_lflag &= ~(C.ECHO | C.ICANON | C.IEXTEN | C.ISIG)
-	raw.c_cc[C.VMIN] = 1
-	raw.c_cc[C.VTIME] = 0
-	C.tcsetattr(0, C.TCSADRAIN, unsafe { &C.termios(&raw) })
+	raw.c_cc[C.VMIN] = byte(1)
+	raw.c_cc[C.VTIME] = byte(0)
+	unsafe { C.tcsetattr(0, C.TCSADRAIN, &raw) }
+	// println('>   after    raw: $raw')
 	r.is_raw = true
 	r.is_tty = true
 }
@@ -68,18 +95,19 @@ pub fn (mut r Readline) enable_raw_mode() {
 // Please note that `enable_raw_mode_nosig` does not catch the `SIGUSER` (CTRL + C) signal
 // as opposed to `enable_raw_mode`.
 pub fn (mut r Readline) enable_raw_mode_nosig() {
-	if C.tcgetattr(0, unsafe { &C.termios(&r.orig_termios) }) == -1 {
+	if unsafe { C.tcgetattr(0, &C.termios(&r.orig_termios)) } != 0 {
 		r.is_tty = false
 		r.is_raw = false
 		return
 	}
-	mut raw := r.orig_termios
+	mut raw := C.termios{}
+	unsafe { vmemcpy(&raw, &r.orig_termios, int(sizeof(raw))) }
 	raw.c_iflag &= ~(C.BRKINT | C.ICRNL | C.INPCK | C.ISTRIP | C.IXON)
 	raw.c_cflag |= C.CS8
 	raw.c_lflag &= ~(C.ECHO | C.ICANON | C.IEXTEN)
-	raw.c_cc[C.VMIN] = 1
-	raw.c_cc[C.VTIME] = 0
-	C.tcsetattr(0, C.TCSADRAIN, unsafe { &C.termios(&raw) })
+	raw.c_cc[C.VMIN] = byte(1)
+	raw.c_cc[C.VTIME] = byte(0)
+	unsafe { C.tcsetattr(0, C.TCSADRAIN, &raw) }
 	r.is_raw = true
 	r.is_tty = true
 }
@@ -88,7 +116,7 @@ pub fn (mut r Readline) enable_raw_mode_nosig() {
 // For a description of raw mode please see the `enable_raw_mode` method.
 pub fn (mut r Readline) disable_raw_mode() {
 	if r.is_raw {
-		C.tcsetattr(0, C.TCSADRAIN, unsafe { &C.termios(&r.orig_termios) })
+		unsafe { C.tcsetattr(0, C.TCSADRAIN, &C.termios(&r.orig_termios)) }
 		r.is_raw = false
 	}
 }
@@ -122,7 +150,7 @@ pub fn (mut r Readline) read_line_utf8(prompt string) ?[]rune {
 	}
 	print(r.prompt)
 	for {
-		C.fflush(C.stdout)
+		unsafe { C.fflush(C.stdout) }
 		c := r.read_char()
 		a := r.analyse(c)
 		if r.execute(a, c) {
@@ -311,7 +339,7 @@ fn (mut r Readline) execute(a Action, c int) bool {
 // get_screen_columns returns the number of columns (`width`) in the terminal.
 fn get_screen_columns() int {
 	ws := Winsize{}
-	cols := if C.ioctl(1, C.TIOCGWINSZ, &ws) == -1 { 80 } else { int(ws.ws_col) }
+	cols := if unsafe { C.ioctl(1, C.TIOCGWINSZ, &ws) } == -1 { 80 } else { int(ws.ws_col) }
 	return cols
 }
 
@@ -542,10 +570,12 @@ fn (mut r Readline) suspend() {
 	r.disable_raw_mode()
 	if !is_standalone {
 		// We have to SIGSTOP the parent v process
-		ppid := C.getppid()
-		C.kill(ppid, C.SIGSTOP)
+		unsafe {
+			ppid := C.getppid()
+			C.kill(ppid, C.SIGSTOP)
+		}
 	}
-	C.raise(C.SIGSTOP)
+	unsafe { C.raise(C.SIGSTOP) }
 	r.enable_raw_mode()
 	r.refresh_line()
 	if r.is_tty {

vlib/readline/readline_test.v

@@ -5,7 +5,7 @@ fn no_lines(s string) string {
 }
 
 fn test_struct_readline() {
-	// mut rl := Readline{}
+	// mut rl := readline.Readline{}
 	// eprintln('rl: $rl')
 	// line := rl.read_line('Please, enter your name: ') or { panic(err) }
 	// eprintln('line: $line')

vlib/readline/readline_windows.c.v

@@ -10,6 +10,10 @@ module readline
 
 import os
 
+// needed for parity with readline_default.c.v
+struct Termios {
+}
+
 // Only use standard os.get_line
 // Need implementation for readline capabilities
 //

vlib/term/declarations_default.c.v

@@ -0,0 +1,10 @@
+module term
+
+pub struct C.termios {
+mut:
+	c_iflag int
+	c_oflag int
+	c_cflag int
+	c_lflag int
+	c_cc    [10]int
+}

vlib/term/declarations_linux.c.v

@@ -0,0 +1,11 @@
+module term
+
+pub struct C.termios {
+mut:
+	c_iflag int
+	c_oflag int
+	c_cflag int
+	c_lflag int
+	c_line  byte
+	c_cc    [10]int
+}

vlib/term/term_nix.c.v

@@ -13,6 +13,10 @@ pub:
 	ws_ypixel u16
 }
 
+fn C.tcgetattr(fd int, ptr &C.termios) int
+
+fn C.tcsetattr(fd int, action int, const_ptr &C.termios)
+
 fn C.ioctl(fd int, request u64, arg voidptr) int
 
 // get_terminal_size returns a number of colums and rows of terminal window.
@@ -21,70 +25,58 @@ pub fn get_terminal_size() (int, int) {
 		return default_columns_size, default_rows_size
 	}
 	w := C.winsize{}
-	C.ioctl(1, u64(C.TIOCGWINSZ), &w)
+	unsafe { C.ioctl(1, u64(C.TIOCGWINSZ), &w) }
 	return int(w.ws_col), int(w.ws_row)
 }
 
 // get_cursor_position returns a Coord containing the current cursor position
-pub fn get_cursor_position() Coord {
+pub fn get_cursor_position() ?Coord {
 	if os.is_atty(1) <= 0 || os.getenv('TERM') == 'dumb' {
-		return Coord{
-			x: 0
-			y: 0
-		}
+		return Coord{0, 0}
 	}
-	// TODO: use termios.h, C.tcgetattr & C.tcsetattr directly,
-	// instead of using `stty`
-	mut oldsettings := os.execute('stty -g')
-	if oldsettings.exit_code < 0 {
-		oldsettings = os.Result{}
+
+	old_state := C.termios{}
+	if unsafe { C.tcgetattr(0, &old_state) } != 0 {
+		return os.last_error()
 	}
-	os.system('stty -echo -icanon time 0')
-	print('\033[6n')
-	mut ch := int(0)
-	mut i := 0
-	// ESC [ YYY `;` XXX `R`
-	mut reading_x := false
-	mut reading_y := false
+	defer {
+		// restore the old terminal state:
+		unsafe { C.tcsetattr(0, C.TCSANOW, &old_state) }
+	}
+
+	mut state := C.termios{}
+	if unsafe { C.tcgetattr(0, &state) } != 0 {
+		return os.last_error()
+	}
+	state.c_lflag &= int(~(u32(C.ICANON) | u32(C.ECHO)))
+	unsafe { C.tcsetattr(0, C.TCSANOW, &state) }
+
+	print('\e[6n')
+
 	mut x := 0
 	mut y := 0
+	mut stage := byte(0)
+
+	// ESC [ YYY `;` XXX `R`
+
 	for {
-		ch = C.getchar()
-		b := byte(ch)
-		i++
-		if i >= 15 {
-			panic('C.getchar() called too many times')
-		}
-		// state management:
-		if b == `R` {
+		w := unsafe { C.getchar() }
+		if w < 0 {
+			return error_with_code('Failed to read from stdin', 888)
+		} else if w == `[` || w == `;` {
+			stage++
+		} else if `0` <= w && w <= `9` {
+			match stage {
+				// converting string values to int:
+				1 { y = y * 10 + int(w - `0`) }
+				2 { x = x * 10 + int(w - `0`) }
+				else {}
+			}
+		} else if w == `R` {
 			break
 		}
-		if b == `[` {
-			reading_y = true
-			reading_x = false
-			continue
-		}
-		if b == `;` {
-			reading_y = false
-			reading_x = true
-			continue
-		}
-		// converting string vals to ints:
-		if reading_x {
-			x *= 10
-			x += (b - byte(`0`))
-		}
-		if reading_y {
-			y *= 10
-			y += (b - byte(`0`))
-		}
-	}
-	// restore the old terminal settings:
-	os.system('stty $oldsettings.output')
-	return Coord{
-		x: x
-		y: y
 	}
+	return Coord{x, y}
 }
 
 // set_terminal_title change the terminal title

vlib/term/term_test.v

@@ -57,23 +57,23 @@ fn test_header() {
 	assert term_width == term.header('1234', '_-/\\/\\').len
 }
 
-fn test_get_cursor_position() {
-	original_position := term.get_cursor_position()
-	cursor_position_1 := term.get_cursor_position()
+fn test_get_cursor_position() ? {
+	original_position := term.get_cursor_position() ?
+	cursor_position_1 := term.get_cursor_position() ?
 	assert original_position.x == cursor_position_1.x
 	assert original_position.y == cursor_position_1.y
 	//
 	term.set_cursor_position(
 		x: 10
 		y: 11
 	)
-	cursor_position_2 := term.get_cursor_position()
+	cursor_position_2 := term.get_cursor_position() ?
 	//
 	term.set_cursor_position(
 		x: 5
 		y: 6
 	)
-	cursor_position_3 := term.get_cursor_position()
+	cursor_position_3 := term.get_cursor_position() ?
 	//
 	term.set_cursor_position(original_position)
 	eprintln('original_position: $original_position')

vlib/term/term_windows.c.v

@@ -69,13 +69,15 @@ pub fn get_terminal_size() (int, int) {
 }
 
 // get_cursor_position returns a Coord containing the current cursor position
-pub fn get_cursor_position() Coord {
+pub fn get_cursor_position() ?Coord {
 	mut res := Coord{}
 	if os.is_atty(1) > 0 && os.getenv('TERM') != 'dumb' {
 		info := C.CONSOLE_SCREEN_BUFFER_INFO{}
 		if C.GetConsoleScreenBufferInfo(C.GetStdHandle(C.STD_OUTPUT_HANDLE), &info) {
 			res.x = info.dwCursorPosition.X
 			res.y = info.dwCursorPosition.Y
+		} else {
+			return os.last_error()
 		}
 	}
 	return res

vlib/term/ui/color.v

@@ -4,10 +4,9 @@
 
 module ui
 
-const (
-	value_range = [0x00, 0x5f, 0x87, 0xaf, 0xd7, 0xff]!
-	color_table = init_color_table()
-)
+const value_range = [0x00, 0x5f, 0x87, 0xaf, 0xd7, 0xff]!
+
+pub const color_table = init_color_table()
 
 [direct_array_access]
 fn init_color_table() []int {