[dwm] xprop patch

I very much like this patch. I realized right away that I would never
again need to restart dwm when I work on my status script. When it
dies, I can just start it up again without restarting DWM. Someone
could even have multiple programs running to update the status text. It
removes the need for the "readin" variable: you either set the property
or you don't.

The patch removes 39 SLOC:

    1546 dwm-5.3.1 ansic=1546
    1585 dwm-5.3.1-orig ansic=1585

This would be 40 if the property were hard coded to XA_WM_NAME. I left
in a comment to use a property named "DWM_STATUS" instead of XA_WM_NAME,
so people could play with it easily, but I think XA_WM_NAME is
ultimately the right way to do it.

To use this, modify your status script to use "xsetroot -name" instead
of "echo". For instance:

    while true; do
        xsetroot -name "$(date)"
        sleep 1
    done

You could also pipe an existing status script to an xsetroot loop like
so:

    status | while read line; do xsetroot -name "$line"; done

If you'd prefer to not use the otherwise-unused WM_NAME property of the
root window, uncomment the commented "statusatom" line, and use xprop as
I detailed in my previous email to the list. I decided WM_NAME was a
good choice, since the default is to display "dwm-"VERSION, and since
xsetroot has a nicer syntax than xprop.

Neale

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diff -ur dwm-5.3.1.orig/config.def.h dwm-5.3.1/config.def.h
--- dwm-5.3.1.orig/config.def.h 2008-12-06 02:33:03.000000000 -0700
+++ dwm-5.3.1/config.def.h 2008-12-08 22:39:49.000000000 -0700
@@ -12,7 +12,6 @@
 static unsigned int snap = 32; /* snap pixel */
 static Bool showbar = True; /* False means no bar */
 static Bool topbar = True; /* False means bottom bar */
-static Bool readin = True; /* False means do not read stdin */
 static Bool usegrab = False; /* True means grabbing the X server
                                                    during mouse-based resizals */
 
diff -ur dwm-5.3.1.orig/dwm.c dwm-5.3.1/dwm.c
--- dwm-5.3.1.orig/dwm.c 2008-12-06 02:33:03.000000000 -0700
+++ dwm-5.3.1/dwm.c 2008-12-08 22:39:49.000000000 -0700
@@ -6,12 +6,9 @@
  * events about window (dis-)appearance. Only one X connection at a time is
  * allowed to select for this event mask.
  *
- * Calls to fetch an X event from the event queue are blocking. Due reading
- * status text from standard input, a select()-driven main loop has been
- * implemented which selects for reads on the X connection and STDIN_FILENO to
- * handle all data smoothly. The event handlers of dwm are organized in an
- * array which is accessed whenever a new event has been fetched. This allows
- * event dispatching in O(1) time.
+ * The event handlers of dwm are organized in an array which is accessed
+ * whenever a new event has been fetched. This allows event dispatching
+ * in O(1) time.
  *
  * Each child of the root window is called a client, except windows which have
  * set the override_redirect flag. Clients are organized in a global
@@ -30,7 +27,6 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-#include <sys/select.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <X11/cursorfont.h>
@@ -196,6 +192,7 @@
 static void updategeom(void);
 static void updatenumlockmask(void);
 static void updatesizehints(Client *c);
+static void updatestatus(void);
 static void updatetitle(Client *c);
 static void updatewmhints(Client *c);
 static void view(const Arg *arg);
@@ -227,7 +224,7 @@
         [PropertyNotify] = propertynotify,
         [UnmapNotify] = unmapnotify
 };
-static Atom wmatom[WMLast], netatom[NetLast];
+static Atom wmatom[WMLast], netatom[NetLast], statusatom;
 static Bool otherwm;
 static Bool running = True;
 static Client *clients = NULL;
@@ -998,9 +995,11 @@
         Window trans;
         XPropertyEvent *ev = &e->xproperty;
 
- if(ev->state == PropertyDelete)
+ if((ev->window == root) && (ev->atom = statusatom))
+ updatestatus();
+ else if(ev->state == PropertyDelete)
                 return; /* ignore */
- if((c = getclient(ev->window))) {
+ else if((c = getclient(ev->window))) {
                 switch (ev->atom) {
                 default: break;
                 case XA_WM_TRANSIENT_FOR:
@@ -1026,7 +1025,7 @@
 
 void
 quit(const Arg *arg) {
- readin = running = False;
+ running = False;
 }
 
 void
@@ -1180,60 +1179,13 @@
 
 void
 run(void) {
- char *p;
- char sbuf[sizeof stext];
- fd_set rd;
- int r, xfd;
- unsigned int len, offset;
         XEvent ev;
 
- /* main event loop, also reads status text from stdin */
+ /* main event loop */
         XSync(dpy, False);
- xfd = ConnectionNumber(dpy);
- offset = 0;
- len = sizeof stext - 1;
- sbuf[len] = stext[len] = '\0'; /* 0-terminator is never touched */
- while(running) {
- FD_ZERO(&rd);
- if(readin)
- FD_SET(STDIN_FILENO, &rd);
- FD_SET(xfd, &rd);
- if(select(xfd + 1, &rd, NULL, NULL, NULL) == -1) {
- if(errno == EINTR)
- continue;
- die("select failed\n");
- }
- if(FD_ISSET(STDIN_FILENO, &rd)) {
- switch((r = read(STDIN_FILENO, sbuf + offset, len - offset))) {
- case -1:
- strncpy(stext, strerror(errno), len);
- readin = False;
- break;
- case 0:
- strncpy(stext, "EOF", 4);
- readin = False;
- break;
- default:
- for(p = sbuf + offset; r > 0; p++, r--, offset++)
- if(*p == '\n' || *p == '\0') {
- *p = '\0';
- strncpy(stext, sbuf, len);
- p += r - 1; /* p is sbuf + offset + r - 1 */
- for(r = 0; *(p - r) && *(p - r) != '\n'; r++);
- offset = r;
- if(r)
- memmove(sbuf, p - r + 1, r);
- break;
- }
- break;
- }
- drawbar();
- }
- while(XPending(dpy)) {
- XNextEvent(dpy, &ev);
- if(handler[ev.type])
- (handler[ev.type])(&ev); /* call handler */
- }
+ while(running && !XNextEvent(dpy, &ev)) {
+ if(handler[ev.type])
+ (handler[ev.type])(&ev); /* call handler */
         }
 }
 
@@ -1322,6 +1274,8 @@
         wmatom[WMState] = XInternAtom(dpy, "WM_STATE", False);
         netatom[NetSupported] = XInternAtom(dpy, "_NET_SUPPORTED", False);
         netatom[NetWMName] = XInternAtom(dpy, "_NET_WM_NAME", False);
+ /* statusatom = XInternAtom(dpy, "DWM_STATUS", False); */
+ statusatom = XA_WM_NAME;
 
         /* init cursors */
         wa.cursor = cursor[CurNormal] = XCreateFontCursor(dpy, XC_left_ptr);
@@ -1356,8 +1310,7 @@
                         CWOverrideRedirect|CWBackPixmap|CWEventMask, &wa);
         XDefineCursor(dpy, barwin, cursor[CurNormal]);
         XMapRaised(dpy, barwin);
- strcpy(stext, "dwm-"VERSION);
- drawbar();
+ updatestatus();
 
         /* EWMH support per view */
         XChangeProperty(dpy, root, netatom[NetSupported], XA_ATOM, 32,
@@ -1365,7 +1318,8 @@
 
         /* select for events */
         wa.event_mask = SubstructureRedirectMask|SubstructureNotifyMask|ButtonPressMask
- |EnterWindowMask|LeaveWindowMask|StructureNotifyMask;
+ |EnterWindowMask|LeaveWindowMask|StructureNotifyMask
+ |PropertyChangeMask;
         XChangeWindowAttributes(dpy, root, CWEventMask|CWCursor, &wa);
         XSelectInput(dpy, root, wa.event_mask);
 
@@ -1647,6 +1601,13 @@
 }
 
 void
+updatestatus() {
+ if(!gettextprop(root, statusatom, stext, sizeof(stext)))
+ strcpy(stext, "dwm-"VERSION);
+ drawbar();
+}
+
+void
 updatewmhints(Client *c) {
         XWMHints *wmh;
 
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Received on Tue Dec 09 2008 - 17:41:35 UTC