Issue with inserting '@' at the command prompt.

Samuel Thibault
Fri Aug 19 02:38:00 GMT 2011

Samuel Thibault, le Thu 14 Jul 2011 14:42:14 +0200, a écrit :
> Lars Bjørndal, le Thu 14 Jul 2011 12:56:21 +0200, a écrit :
> > BRLTTY has a cut & paste facility. It sometimes doesn't paste all
> > characters inside cygwin. Pasting an att sign into a shell prompt, the
> > terminal beeps, and no character is written. Doing the same thing
> > after exiting bash, but still with BRLTTY running and in a cmd
> > session, the att sign is printed.
> I don't have the time to investigate now, but I can say that depending
> on whether it could open the terminal through CONIN$, brltty uses
> WriteConsoleInputW (or WriteConsoleInputA if not available) or SendInput
> for this.

In the case at stake it is WriteConsoleInputW. Let me explain a simpler
case (pasting is the same)

- the user presses '@' on his braille keyboard (ascii 0x40).
- brltty wants to synthesize it.
- brltty calls VkKeyScanW('@') to get the corresponding virtual key,
  0x0630 on an azerty keyboard, which means altgr (controlkeystate 1) +
  virtualkey 0x30
- brltty calls MapVirtualKey(vk, 0) to get the corresponding scancode,
  0x11 on a standard PC keyboard.
- brltty thus calls WriteConsoleInputW, passing it a KEY_EVENT_RECORD
  .bKeyDown = 1,
  .wRepeatCount = 1,
  .wVirtualKeyCode = 0x630,
  .wVirtualScanCode = 0x11,
  .uChar.UnicodeChar = 0x40,
  .dwControlKeyState = 1,

and then the same with bKeyDown = 0.

This correctly inserts an '@' in a plain windows console with the
windows cmd, but with a windows console with the cygwin or mingw shell,
this beeps and does not insert anything.

Any idea?


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