libxdo and WM_CLASS

output

% ./a.out $WINDOWID
Items: 22
Type: STRING
WM_CLASS[0]: terminator
WM_CLASS[1]: Terminator

test.c

#include <xdo.h>
#include <stdio.h>
#include <string.h>

int main(int argc, char **argv) {
  Window id;
  xdo_t *xdo = xdo_new(NULL);
  char *prop;
  long nitems;
  Atom type;
  int size;
  
  if (argc != 2) {
    printf("Usage: %s <windowid>\n", argv[0]);
    return 1;
  }
  
  id = atol(argv[1]);
  prop = xdo_getwinprop(xdo, id, XInternAtom(xdo->xdpy, "WM_CLASS", False),
                        &nitems, &type, &size);

  printf("Items: %d\n", nitems);
  printf("Type: %s\n", XGetAtomName(xdo->xdpy, type));

  int len;
  int chars = nitems;
  int index = 0;
  while (chars > 0) {
    printf("WM_CLASS[%d]: %s\n", index, prop);
    len = strlen(prop) + 1; /* +1 for the null byte */
    prop += len;
    chars -= len;
    index += 1;
  }

  return 0;
}

xdo_getwinprop > xdo_get_window_property_by_atom