terraform/vendor/github.com/chzyer/readline/utils_unix.go

91 lines
1.6 KiB
Go

// +build darwin dragonfly freebsd linux,!appengine netbsd openbsd
package readline
import (
"io"
"os"
"os/signal"
"sync"
"syscall"
"unsafe"
)
type winsize struct {
Row uint16
Col uint16
Xpixel uint16
Ypixel uint16
}
// SuspendMe use to send suspend signal to myself, when we in the raw mode.
// For OSX it need to send to parent's pid
// For Linux it need to send to myself
func SuspendMe() {
p, _ := os.FindProcess(os.Getppid())
p.Signal(syscall.SIGTSTP)
p, _ = os.FindProcess(os.Getpid())
p.Signal(syscall.SIGTSTP)
}
// get width of the terminal
func getWidth(stdoutFd int) int {
ws := &winsize{}
retCode, _, errno := syscall.Syscall(syscall.SYS_IOCTL,
uintptr(stdoutFd),
uintptr(syscall.TIOCGWINSZ),
uintptr(unsafe.Pointer(ws)))
if int(retCode) == -1 {
_ = errno
return -1
}
return int(ws.Col)
}
func GetScreenWidth() int {
w := getWidth(syscall.Stdout)
if w < 0 {
w = getWidth(syscall.Stderr)
}
return w
}
// ClearScreen clears the console screen
func ClearScreen(w io.Writer) (int, error) {
return w.Write([]byte("\033[H"))
}
func DefaultIsTerminal() bool {
return IsTerminal(syscall.Stdin) && (IsTerminal(syscall.Stdout) || IsTerminal(syscall.Stderr))
}
func GetStdin() int {
return syscall.Stdin
}
// -----------------------------------------------------------------------------
var (
widthChange sync.Once
widthChangeCallback func()
)
func DefaultOnWidthChanged(f func()) {
widthChangeCallback = f
widthChange.Do(func() {
ch := make(chan os.Signal, 1)
signal.Notify(ch, syscall.SIGWINCH)
go func() {
for {
_, ok := <-ch
if !ok {
break
}
widthChangeCallback()
}
}()
})
}