packer-cn/helper/wrappedreadline/wrappedreadline_unix.go

53 lines
944 B
Go

// +build darwin dragonfly freebsd linux,!appengine netbsd openbsd
package wrappedreadline
import (
"os"
"syscall"
"unsafe"
)
// getWidth impl for Unix
func getWidth() int {
stdoutFd := int(Stdout().Fd())
stderrFd := int(Stderr().Fd())
w := getWidthFd(stdoutFd)
if w < 0 {
w = getWidthFd(stderrFd)
}
return w
}
type winsize struct {
Row uint16
Col uint16
Xpixel uint16
Ypixel uint16
}
// get width of the terminal
func getWidthFd(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 init() {
// The standard streams are passed in via extra file descriptors.
wrappedStdin = os.NewFile(uintptr(3), "stdin")
wrappedStdout = os.NewFile(uintptr(4), "stdout")
wrappedStderr = os.NewFile(uintptr(5), "stderr")
}