How to map a X11 KeySym to a Unicode character?

Question

This is an exact duplicate of this question; however the code linked in the accepted answer is nearly 11 years old, and this comment in the code leads to my duplicate question:

The keysym -> UTF-8 conversion will hopefully one day be provided by Xlib via XmbLookupString() and should ideally not have to be done in X applications. But we are not there yet.

Are we there yet? I'm aware of XwcLookupString, but something like...

wchar_t unicode = XKeySymToWideChar( keysym );

... would be much simpler and logical, and not require updating whenever KeySyms are added or changed.

Is there a simple function in X11/Xlib that will map a KeySym to its Unicode equivalent?

Answer 1

Try this node.js module to generate C table: https://github.com/substack/node-keysym . It is based on this dataset: https://github.com/substack/node-keysym/blob/master/data/keysyms.txt

Answer 2

Is there a simple function in X11/Xlib that will map a KeySym to its Unicode equivalent?

The definitive answer is no

Because Unicode was invented years after Xlib and no one ever went back to add such a thing? Most of the Xlib API is codeset independent since it was written in the days when every locale used a different character set (ISO 8859-*, Big5, JIS, etc.), so you get a char buffer appropriate to the current locale. There were a few UTF-8 specific additions in later years, but mostly we've been trying to let Xlib rest in peace since then, pushing new API design towards xcb instead.

Answer 3

This may help somebody... adapted from xmodmap source and online doc (http://tronche.com/gui/x/xlib/utilities/keyboard/XKeycodeToKeysym.html)

KeySym ks = XKeycodeToKeysym(dpy, keycode+min_keycode, modifier);
const char *s;
if (ks != NoSymbol)
    s = XKeysymToString (ks);
else {
    printf("Keycode has no symbol. Ignored.\n");
    return NULL;
}

printf ("0x%04x (%s)\n", (unsigned int)ks, s);
printf ("wide char:%lc\n", (wchar_t)ks);

Keysym is already the UTF value. The problem would be to set keycombinations... 'á' for example.