implemented reapply for re-applying the tagging rules during runtime, Mod-r

config.def.h

@@ -47,6 +47,7 @@ Key keys[] = {
 	{ MODKEY,			XK_h,		setmwfact,	"-0.05" },
 	{ MODKEY,			XK_l,		setmwfact,	"+0.05" },
 	{ MODKEY,			XK_m,		togglemax,	NULL },
+	{ MODKEY,			XK_r,		reapply,	NULL },
 	{ MODKEY,			XK_Return,	zoom,		NULL },
 	{ MODKEY,			XK_Tab,		viewprevtag,	NULL },
 	{ MODKEY|ShiftMask,		XK_space,	togglefloating,	NULL },

dwm.1

@@ -80,6 +80,9 @@ Increases the master area width about 5% (tiled layout only).
 .B Mod1\-m
 Toggles maximization of current window.
 .TP
+.B Mod1\-r
+Re-applies tagging rules to all windows.
+.TP
 .B Mod1\-Shift\-[1..n]
 Apply
 .RB nth

dwm.c

@@ -161,6 +161,7 @@ void movemouse(Client *c);
 Client *nexttiled(Client *c);
 void propertynotify(XEvent *e);
 void quit(const char *arg);
+void reapply(const char *arg);
 void resize(Client *c, int x, int y, int w, int h, Bool sizehints);
 void resizemouse(Client *c);
 void restack(void);
@@ -1159,6 +1160,17 @@ quit(const char *arg) {
 	readin = running = False;
 }
 
+void
+reapply(const char *arg) {
+	static Bool zerotags[LENGTH(tags)] = { 0 };
+	Client *c;
+
+	for(c = clients; c; c = c->next) {
+		memcpy(c->tags, zerotags, sizeof zerotags);
+		applyrules(c);
+	}
+	arrange();
+}
 
 void
 resize(Client *c, int x, int y, int w, int h, Bool sizehints) {