Interesting question! Offhand, I don't know of any tools that can do
this (though I didn't look very far). So I knocked together a tiny
little program that might be useful to you. I'm afraid it's written in
C, so if you're new to Ubuntu and GNU/Linux, compiling and running it
may be a little bit of a challenge, sorry about that! :) If anyone has
any better ideas, I'd be interested to know (maybe port it to Python?).
I've put the listing at the end, between the '//////' markers, in case
this mailing-list doesn't like attachments.
Brief instructions:
Save the listing to a file named lockdisplay.c in your Home directory.
Install the needed development tools:
sudo apt-get install build-essential libx11-dev
Compile the program:
gcc -lX11 lockdisplay.c -o lockdisplay
Run it with:
./lockdisplay
When it's running, it will lock the keyboard and mouse, but programs
(such as a video player) will continue to run on the screen. Type in
the password "ubuntu" to stop the program and release the lock.
Unfortunately, it won't trap any special X server key-sequences (such as
Ctrl-Alt-F2 or Ctrl-Alt-Backspace). I don't know how to trap these, but
I think it must be possible, because VMWare Server manages to do it.
You can do whatever you want with this code - it works for me, but
please don't hold me responsible for anything that breaks! :)
Lambros Lambrou
//////
// Compile this with
// gcc -lX11 lockdisplay.c -o lockdisplay
#include <X11/Xlib.h>
#include <stdio.h>
int main()
{
Display *dpy;
XEvent xevent;
Window w;
const char *password = "ubuntu";
int correct_keys = 0;
dpy = XOpenDisplay(NULL);
if (!dpy) {
fprintf(stderr, "Couldn't open X display %s\n",
XDisplayName(NULL));
return 1;
}
// Lock keyboard and mouse
w = RootWindow(dpy, DefaultScreen(dpy));
XGrabKeyboard(dpy, w, False,
GrabModeAsync, GrabModeAsync, CurrentTime);
XGrabPointer(dpy, w, False, 0,
GrabModeAsync, GrabModeAsync,
None, None, CurrentTime);
// X Event-handling loop.
// Look at keypress events and compare them with the password,
// one letter at a time.
while (1) {
XNextEvent(dpy, &xevent);
if (xevent.type == KeyPress) {
XKeyEvent *ke = (XKeyEvent *)&xevent;
KeySym keysym;
XLookupString(ke, NULL, 0, &keysym, NULL);
//printf("Got keysym %d, '%c'\n", keysym, keysym);
if (keysym == password[correct_keys]) {
correct_keys++;
//printf("Correct key pressed\n");
if (password[correct_keys] == '\0') {
//printf("Password fully typed, exiting.\n");
break;
}
} else {
correct_keys = 0;
//printf("Wrong key, reset to beginning\n");
}
}
}
XCloseDisplay(dpy);
return 0;
}
//////
On Wed, 2008-06-25 at 17:24 +0100, [EMAIL PROTECTED]
wrote:
> Message: 3
> Date: Wed, 25 Jun 2008 16:38:43 +0100
> From: Andrew Oakley <[EMAIL PROTECTED]>
> Subject: [ubuntu-uk] Lock keyboard/mouse without locking screen?
> To: British Ubuntu Talk <ubuntu-uk@lists.ubuntu.com>
> Message-ID: <[EMAIL PROTECTED]>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>
> I have a two-year old daughter and an Ubuntu laptop (Hardy on a Dell
> Inspiron 1520).
>
> How do I lock the keyboard and mouse without locking the screen? I
> realise this may require installing new packages.
>
> For example, I want to be able to play a video on the laptop, whilst
> my
> daughter to bashes the keys and clicks the mouse. Ideally the
> keyboard/mouse would only be unlocked once a particularly difficult
> key
> combination or sequence is pressed.
>
> I don't intend to leave my daughter alone with the laptop (result
> would
> probably be Ribena spilt over it), but I would like to be able to sit
> on
> the other side of the room and not have to constantly pull her away
> from it.
>
> --
> Andrew Oakley
>
>
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