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restic/internal/ui/termstatus/terminal_windows.go
Michael Eischer b48f579530 termstatus: Fix canUpdateStatus detection for redirected output
The canUpdateStatus check was simplified in #2608, but it accidentally flipped
the condition. The correct check is as follows: If the output is a pipe then
restic probably runs in mintty/cygwin. In that case it's possible to
update the output status. In all other cases it isn't.

This commit inverts to condition again to offer the previous and correct
behavior.
2020-12-06 19:02:42 +01:00

99 lines
2.9 KiB
Go

// +build windows
package termstatus
import (
"io"
"syscall"
"unsafe"
"golang.org/x/crypto/ssh/terminal"
"golang.org/x/sys/windows"
)
// clearCurrentLine removes all characters from the current line and resets the
// cursor position to the first column.
func clearCurrentLine(wr io.Writer, fd uintptr) func(io.Writer, uintptr) {
// easy case, the terminal is cmd or psh, without redirection
if isWindowsTerminal(fd) {
return windowsClearCurrentLine
}
// assume we're running in mintty/cygwin
return posixClearCurrentLine
}
// moveCursorUp moves the cursor to the line n lines above the current one.
func moveCursorUp(wr io.Writer, fd uintptr) func(io.Writer, uintptr, int) {
// easy case, the terminal is cmd or psh, without redirection
if isWindowsTerminal(fd) {
return windowsMoveCursorUp
}
// assume we're running in mintty/cygwin
return posixMoveCursorUp
}
var kernel32 = syscall.NewLazyDLL("kernel32.dll")
var (
procFillConsoleOutputCharacter = kernel32.NewProc("FillConsoleOutputCharacterW")
procFillConsoleOutputAttribute = kernel32.NewProc("FillConsoleOutputAttribute")
)
// windowsClearCurrentLine removes all characters from the current line and
// resets the cursor position to the first column.
func windowsClearCurrentLine(wr io.Writer, fd uintptr) {
var info windows.ConsoleScreenBufferInfo
windows.GetConsoleScreenBufferInfo(windows.Handle(fd), &info)
// clear the line
cursor := windows.Coord{
X: info.Window.Left,
Y: info.CursorPosition.Y,
}
var count, w uint32
count = uint32(info.Size.X)
procFillConsoleOutputAttribute.Call(fd, uintptr(info.Attributes), uintptr(count), *(*uintptr)(unsafe.Pointer(&cursor)), uintptr(unsafe.Pointer(&w)))
procFillConsoleOutputCharacter.Call(fd, uintptr(' '), uintptr(count), *(*uintptr)(unsafe.Pointer(&cursor)), uintptr(unsafe.Pointer(&w)))
}
// windowsMoveCursorUp moves the cursor to the line n lines above the current one.
func windowsMoveCursorUp(wr io.Writer, fd uintptr, n int) {
var info windows.ConsoleScreenBufferInfo
windows.GetConsoleScreenBufferInfo(windows.Handle(fd), &info)
// move cursor up by n lines and to the first column
windows.SetConsoleCursorPosition(windows.Handle(fd), windows.Coord{
X: 0,
Y: info.CursorPosition.Y - int16(n),
})
}
// isWindowsTerminal return true if the file descriptor is a windows terminal (cmd, psh).
func isWindowsTerminal(fd uintptr) bool {
return terminal.IsTerminal(int(fd))
}
func isPipe(fd uintptr) bool {
typ, err := windows.GetFileType(windows.Handle(fd))
return err == nil && typ == windows.FILE_TYPE_PIPE
}
// canUpdateStatus returns true if status lines can be printed, the process
// output is not redirected to a file or pipe.
func canUpdateStatus(fd uintptr) bool {
// easy case, the terminal is cmd or psh, without redirection
if isWindowsTerminal(fd) {
return true
}
// check that the output file type is a pipe (0x0003)
if !isPipe(fd) {
return false
}
// assume we're running in mintty/cygwin
return true
}