Only in dwm-5.6.1: blinking_urgent.patch
Only in dwm-5.6.1: blinking_urgent.patch~
diff -up dwm-5.6.1/dwm.c dwm-5.6.1rc/dwm.c
--- dwm-5.6.1/dwm.c	2009-07-26 15:01:50.000000000 +0200
+++ dwm-5.6.1rc/dwm.c	2009-08-22 22:44:53.796226140 +0200
@@ -36,11 +36,13 @@
 #include <X11/Xlib.h>
 #include <X11/Xproto.h>
 #include <X11/Xutil.h>
+#include <pthread.h>
 #ifdef XINERAMA
 #include <X11/extensions/Xinerama.h>
 #endif /* XINERAMA */
 
 /* macros */
+#define NUM_THREADS             1
 #define BUTTONMASK              (ButtonPressMask|ButtonReleaseMask)
 #define CLEANMASK(mask)         (mask & ~(numlockmask|LockMask))
 #define INRECT(X,Y,RX,RY,RW,RH) ((X) >= (RX) && (X) < (RX) + (RW) && (Y) >= (RY) && (Y) < (RY) + (RH))
@@ -266,6 +268,8 @@ static Display *dpy;
 static DC dc;
 static Monitor *mons = NULL, *selmon = NULL;
 static Window root;
+int blinkurgent = True;
+int redraw_needed = False;
 
 /* configuration, allows nested code to access above variables */
 #include "config.h"
@@ -496,10 +500,28 @@ cleanupmons(void) {
 }
 
 void
+*blinktoggle(void *threadid) {
+  int temp = 1;
+  long tid;
+  tid = (long)threadid;
+  unsigned int sec;
+  sec = 1;
+  while(temp == 1) {
+     blinkurgent = !blinkurgent;
+     if(redraw_needed) drawbars();
+     sleep(sec);
+  }
+  pthread_exit(NULL);
+}
+
+
+void
 clearurgent(Client *c) {
 	XWMHints *wmh;
 
 	c->isurgent = False;
+	blinkurgent = False;
+	redraw_needed = False;
 	if(!(wmh = XGetWMHints(dpy, c->win)))
 		return;
 	wmh->flags &= ~XUrgencyHint;
@@ -657,8 +679,8 @@ drawbar(Monitor *m) {
 		if(ISVISIBLE(c))
 			n++;
 		occ |= c->tags;
-		if(c->isurgent)
-			urg |= c->tags;
+		if(c->isurgent && blinkurgent)
+		           urg |= c->tags;
 	}
 	dc.x = 0;
 	for(i = 0; i < LENGTH(tags); i++) {
@@ -1847,6 +1869,12 @@ updatewmhints(Client *c) {
 		}
 		else
 			c->isurgent = (wmh->flags & XUrgencyHint) ? True : False;
+		if(c->isurgent) {
+		  redraw_needed = True;
+		}
+	        else {
+		  redraw_needed = False;
+		}
 		XFree(wmh);
 	}
 }
@@ -1941,7 +1969,8 @@ zoom(const Arg *arg) {
 
 int
 main(int argc, char *argv[]) {
-	if(argc == 2 && !strcmp("-v", argv[1]))
+        XInitThreads();
+        if(argc == 2 && !strcmp("-v", argv[1]))
 		die("dwm-"VERSION", © 2006-2009 dwm engineers, see LICENSE for details\n");
 	else if(argc != 1)
 		die("usage: dwm [-v]\n");
@@ -1949,11 +1978,24 @@ main(int argc, char *argv[]) {
 		fputs("warning: no locale support\n", stderr);
 	if(!(dpy = XOpenDisplay(NULL)))
 		die("dwm: cannot open display\n");
+
+	pthread_t threads[NUM_THREADS];
+	int rc;
+	long t;
+	for(t=0; t<NUM_THREADS; t++){
+	  printf("In main: creating thread %ld\n", t);
+	  rc = pthread_create(&threads[0], NULL, blinktoggle, (void *)t);
+	  if (rc){
+	    printf("ERROR; return code from pthread_create() is %d\n", rc);
+	    exit(-1);
+	  }
+	}	
 	checkotherwm();
 	setup();
 	scan();
 	run();
 	cleanup();
 	XCloseDisplay(dpy);
+	pthread_exit(NULL);
 	return 0;
 }
diff -up dwm-5.6.1/Makefile dwm-5.6.1rc/Makefile
--- dwm-5.6.1/Makefile	2009-07-26 15:01:50.000000000 +0200
+++ dwm-5.6.1rc/Makefile	2009-08-22 22:42:36.038242547 +0200
@@ -5,6 +5,7 @@ include config.mk
 
 SRC = dwm.c
 OBJ = ${SRC:.c=.o}
+LDFLAGS += "-lpthread"
 
 all: options dwm