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subgraph-oz/oz/term.go

112 lines
2.6 KiB

package main
import (
"syscall"
"unsafe"
"os"
"os/signal"
"fmt"
)
type winsize struct {
Height uint16
Width uint16
x uint16
y uint16
}
type State struct {
termios Termios
}
const (
getTermios = syscall.TCGETS
setTermios = syscall.TCSETS
)
type Termios struct {
Iflag uint32
Oflag uint32
Cflag uint32
Lflag uint32
Cc [20]byte
Ispeed uint32
Ospeed uint32
}
// MakeRaw put the terminal connected to the given file descriptor into raw
// mode and returns the previous state of the terminal so that it can be
// restored.
func MakeRaw(fd uintptr) (*State, error) {
var oldState State
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, getTermios, uintptr(unsafe.Pointer(&oldState.termios))); err != 0 {
return nil, err
}
newState := oldState.termios
newState.Iflag &^= (syscall.IGNBRK | syscall.BRKINT | syscall.PARMRK | syscall.ISTRIP | syscall.INLCR | syscall.IGNCR | syscall.ICRNL | syscall.IXON)
newState.Oflag &^= syscall.OPOST
newState.Lflag &^= (syscall.ECHO | syscall.ECHONL | syscall.ICANON | syscall.ISIG | syscall.IEXTEN)
newState.Cflag &^= (syscall.CSIZE | syscall.PARENB)
newState.Cflag |= syscall.CS8
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, setTermios, uintptr(unsafe.Pointer(&newState))); err != 0 {
return nil, err
}
return &oldState, nil
}
// Restore restores the terminal connected to the given file descriptor to a
// previous state.
func RestoreTerminal(fd uintptr, state *State) error {
_, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, uintptr(setTermios), uintptr(unsafe.Pointer(&state.termios)))
return err
}
func SetRawTerminal(fd uintptr) (*State, error) {
oldState, err := MakeRaw(fd)
if err != nil {
return nil, err
}
c := make(chan os.Signal, 1)
signal.Notify(c, os.Interrupt)
go func() {
_ = <-c
RestoreTerminal(fd, oldState)
os.Exit(0)
}()
return oldState, err
}
func GetWinsize(fd uintptr) (*winsize, syscall.Errno) {
ws := &winsize{}
_, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, uintptr(syscall.TIOCGWINSZ), uintptr(unsafe.Pointer(ws)))
return ws, err
}
func SetWinsize(fd uintptr, ws *winsize) syscall.Errno {
_, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, uintptr(syscall.TIOCSWINSZ), uintptr(unsafe.Pointer(ws)))
return err
}
func HandleResize(fd int) {
sigs := make(chan os.Signal)
signal.Notify(sigs, syscall.SIGWINCH)
go func() {
for {
<-sigs
handleSIGWINCH(fd)
}
}()
handleSIGWINCH(fd)
}
func handleSIGWINCH(fd int) {
ws,errno := GetWinsize(0)
if errno != 0 {
fmt.Printf("error reading winsize: %v\n", errno.Error())
return
}
if errno := SetWinsize(uintptr(fd), ws); errno != 0 {
fmt.Printf("error setting winsize: %v", errno.Error())
}
}