Add terminal pkg

pkg/terminal/terminal.go

@@ -0,0 +1,98 @@
+package terminal
+
+import (
+	"fmt"
+	"syscall"
+	"unsafe"
+)
+
+const (
+	ClearScreen   = "\u001Bc"
+	CursorHide    = "\u001B[?25l"
+	CursorShow    = "\u001B[?25h"
+	CursorTopLeft = "\u001B[H"
+	EraseLine     = "\u001B[K"
+
+	SetCursorFmt = "\u001B[%d;%dH"
+)
+
+type Terminal struct {
+	fd      uintptr
+	termios *syscall.Termios
+}
+
+type Size struct {
+	Rows    uint16
+	Columns uint16
+	XPixels uint16
+	YPixels uint16
+}
+
+func New(fd uintptr) (*Terminal, error) {
+	var t = &Terminal{
+		termios: &syscall.Termios{},
+	}
+
+	if _, _, err := syscall.Syscall(
+		syscall.SYS_IOCTL,
+		fd,
+		syscall.TCGETS,
+		uintptr(unsafe.Pointer(t.termios)),
+	); err != 0 {
+		return nil, fmt.Errorf("ioctl syscall: %w", err)
+	}
+
+	return t, nil
+}
+
+// Reset the terminal into the original termios.
+func (t *Terminal) Reset() error {
+	if _, _, err := syscall.Syscall(
+		syscall.SYS_IOCTL,
+		t.fd,
+		uintptr(syscall.TCSETS),
+		uintptr(unsafe.Pointer(t.termios)),
+	); err != 0 {
+		return fmt.Errorf("ioctl syscall: %w", err)
+	}
+
+	return nil
+}
+
+// SetRaw enables raw mode.
+func (t *Terminal) SetRaw() error {
+	var termios = *t.termios
+	termios.Iflag &^= syscall.IGNBRK | syscall.BRKINT | syscall.PARMRK | syscall.ISTRIP | syscall.INLCR | syscall.IGNCR | syscall.ICRNL | syscall.IXON
+	termios.Oflag &^= syscall.OPOST
+	termios.Lflag &^= syscall.ECHO | syscall.ECHONL | syscall.ICANON | syscall.ISIG | syscall.IEXTEN
+	termios.Cflag &^= syscall.CSIZE | syscall.PARENB
+	termios.Cflag |= syscall.CS8
+	termios.Cc[syscall.VMIN] = 1
+	termios.Cc[syscall.VTIME] = 0
+
+	if _, _, err := syscall.Syscall(
+		syscall.SYS_IOCTL,
+		t.fd,
+		uintptr(syscall.TCSETS),
+		uintptr(unsafe.Pointer(&termios)),
+	); err != 0 {
+		return fmt.Errorf("ioctl syscall: %w", err)
+	}
+
+	return nil
+}
+
+// Size returns the zero-indexed size of the terminal.
+func (t *Terminal) Size() (*Size, error) {
+	var size = &Size{}
+	if _, _, err := syscall.Syscall(
+		syscall.SYS_IOCTL,
+		t.fd,
+		syscall.TIOCGWINSZ,
+		uintptr(unsafe.Pointer(size)),
+	); err != 0 {
+		return nil, fmt.Errorf("ioctl syscall: %w", err)
+	}
+
+	return size, nil
+}