1 files changed, 31 insertions, 0 deletions
diff --git a/src/utils.c b/src/utils.c
new file mode 100644
index 0000000..c99e74c
--- /dev/null
+++ b/src/utils.c
@@ -0,0 +1,31 @@
+#include <err.h>
+#include <X11/Xlib.h>
+#include "util.h"
+
+void
+otherwm(void)
+{
+	XSetErrorHandler(otherwmerr);
+	XChangeWindowAttributes(dpy, root, CWEventMask, 
+			&(XSetWindowAttributes){.event_mask = SubstructureRedirectMask});
+	XSync(dpy, False);
+	XSetErrorHandler(xerr);
+	XSync(dpy, False);
+}
+
+int
+otherwmerr(Display *dpy, XErrorEvent *ee)
+{
+	errx(0, "sxwm: another window manager is already running, please close it");
+	return 0;
+	if (dpy && ee) return 0;
+}
+
+int
+xerr(Display *dpy, XErrorEvent *ee)
+{
+	fprintf(stderr, "sxwm: fatal error\nrequest code:%d\nerror code:%d",
+			ee->request_code, ee->error_code);
+	return 0;
+	if (dpy && ee) return 0;
+}