XChangeProperty/XGetWindowProperty problem

[Antoine Martin]

You're using using format=32, which means `CARD32` aka `unsigned long`, 
not to be confused with 32-bit integers, despite its name.
Switch from `int32_t` to `unsigned long`.

Cheers,
Antoine

On 09/05/2025 13:56, 406643764 wrote:
> Hi, all.
> I use XChangeProperty/XGetWindowProperty as following code:
> #include <stdio.h>
> #include <X11/Xlib.h>
> #include <X11/Xatom.h>
> 
> int main(void)
> {
>      Display *display=XOpenDisplay(NULL);
>      int screen=DefaultScreen(display);
>      Window root_win=RootWindow(display, screen);
> 
>      Window win=XCreateSimpleWindow(display, root_win, -1, -1, 1, 1, 0, 
> 0, 0);
>      Atom prop=XInternAtom(display, "test_prop", False);
>      Atom type=XInternAtom(display, "test_type", False);
>      int32_t a[]={0x11223344, 0x55667788};
>      XChangeProperty(display, win, prop, type, 32, PropModeReplace, 
> (unsigned char *)a, 2);
> 
>      int fmt;
>      unsigned long nitems=0, n=0, rest;
>      unsigned char *p=NULL;
>      Atom atype;
>      if( XGetWindowProperty(display, win, prop, 0, 2, False,
>          type, &atype, &fmt, &n, &rest, &p) != Success
>          || !atype || !fmt || !n || !p)
>          XFree(p), p=NULL;
>      long *d=(long *)p;
>      printf("%lx, %lx, %lu\n", d[0], d[1], rest);
> 
>      XCloseDisplay(display);
> 
>      return 0;
> }
> 
> But the output is:
> 
> 11223344, 1, 0
> 
> It should be:
> 
> 11223344, 55667788, 0
> 
> What's wrong ?
> 
> ------------------------------------------------------------------------
> 	
> 406643764
> 406643764 at qq.com
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