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132 lines
3.2 KiB
Go
132 lines
3.2 KiB
Go
// +build !windows
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// Package term provides provides structures and helper functions to work with
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// terminal (state, sizes).
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package term
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import (
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"errors"
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"io"
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"os"
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"os/signal"
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"syscall"
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"unsafe"
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)
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var (
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// ErrInvalidState is returned if the state of the terminal is invalid.
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ErrInvalidState = errors.New("Invalid terminal state")
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)
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// State represents the state of the terminal.
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type State struct {
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termios Termios
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}
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// Winsize represents the size of the terminal window.
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type Winsize struct {
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Height uint16
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Width uint16
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x uint16
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y uint16
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}
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// StdStreams returns the standard streams (stdin, stdout, stedrr).
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func StdStreams() (stdIn io.ReadCloser, stdOut, stdErr io.Writer) {
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return os.Stdin, os.Stdout, os.Stderr
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}
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// GetFdInfo returns the file descriptor for an os.File and indicates whether the file represents a terminal.
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func GetFdInfo(in interface{}) (uintptr, bool) {
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var inFd uintptr
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var isTerminalIn bool
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if file, ok := in.(*os.File); ok {
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inFd = file.Fd()
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isTerminalIn = IsTerminal(inFd)
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}
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return inFd, isTerminalIn
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}
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// GetWinsize returns the window size based on the specified file descriptor.
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func GetWinsize(fd uintptr) (*Winsize, error) {
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ws := &Winsize{}
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_, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, uintptr(syscall.TIOCGWINSZ), uintptr(unsafe.Pointer(ws)))
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// Skip errno = 0
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if err == 0 {
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return ws, nil
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}
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return ws, err
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}
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// SetWinsize tries to set the specified window size for the specified file descriptor.
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func SetWinsize(fd uintptr, ws *Winsize) error {
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_, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, uintptr(syscall.TIOCSWINSZ), uintptr(unsafe.Pointer(ws)))
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// Skip errno = 0
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if err == 0 {
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return nil
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}
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return err
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}
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// IsTerminal returns true if the given file descriptor is a terminal.
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func IsTerminal(fd uintptr) bool {
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var termios Termios
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return tcget(fd, &termios) == 0
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}
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// RestoreTerminal restores the terminal connected to the given file descriptor
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// to a previous state.
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func RestoreTerminal(fd uintptr, state *State) error {
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if state == nil {
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return ErrInvalidState
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}
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if err := tcset(fd, &state.termios); err != 0 {
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return err
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}
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return nil
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}
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// SaveState saves the state of the terminal connected to the given file descriptor.
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func SaveState(fd uintptr) (*State, error) {
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var oldState State
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if err := tcget(fd, &oldState.termios); err != 0 {
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return nil, err
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}
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return &oldState, nil
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}
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// DisableEcho applies the specified state to the terminal connected to the file
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// descriptor, with echo disabled.
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func DisableEcho(fd uintptr, state *State) error {
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newState := state.termios
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newState.Lflag &^= syscall.ECHO
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if err := tcset(fd, &newState); err != 0 {
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return err
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}
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handleInterrupt(fd, state)
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return nil
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}
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// SetRawTerminal puts the terminal connected to the given file descriptor into
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// raw mode and returns the previous state.
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func SetRawTerminal(fd uintptr) (*State, error) {
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oldState, err := MakeRaw(fd)
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if err != nil {
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return nil, err
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}
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handleInterrupt(fd, oldState)
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return oldState, err
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}
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func handleInterrupt(fd uintptr, state *State) {
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sigchan := make(chan os.Signal, 1)
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signal.Notify(sigchan, os.Interrupt)
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go func() {
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_ = <-sigchan
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RestoreTerminal(fd, state)
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os.Exit(0)
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}()
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}
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