Set page(1)'s window label to the name of the currently displayed file.

Reference: /n/sources/patch/applied/page-label
Date: Thu Jul  7 05:39:34 CES 2011
Signed-off-by: lyndon@orthanc.ca

--- /sys/src/cmd/page/gfx.c	Thu Jul  7 05:38:12 2011
+++ /sys/src/cmd/page/gfx.c	Thu Jul  7 05:38:10 2011
@@ -87,6 +87,7 @@
 static Image*
 gfxdrawpage(Document *doc, int page)
 {
+	setlabel(gfxpagename(doc, page));
 	GfxInfo *gfx = doc->extra;
 	return convert(gfx->g+page);
 }
--- /sys/src/cmd/page/page.h	Thu Jul  7 05:38:16 2011
+++ /sys/src/cmd/page/page.h	Thu Jul  7 05:38:14 2011
@@ -25,6 +25,7 @@
 Document *inittroff(Biobuf*, int, char**, uchar*, int);
 Document *initdvi(Biobuf*, int, char**, uchar*, int);
 Document *initmsdoc(Biobuf*, int, char**, uchar*, int);
+void setlabel(char *);
 
 void viewer(Document*);
 extern Cursor reading;
--- /sys/src/cmd/page/util.c	Thu Jul  7 05:38:20 2011
+++ /sys/src/cmd/page/util.c	Thu Jul  7 05:38:18 2011
@@ -129,3 +129,20 @@
 	_exits(0);
 	return -1;	/* not reached */
 }
+
+/* try to update the label, but don't fail on any errors */
+void
+setlabel(char *label)
+{
+	char *s;
+	int fd;
+	
+	s = smprint("%s/label", display->windir);
+	fd = open(s, OWRITE);
+	free(s);
+	if(fd >= 0){
+		write(fd, label, strlen(label));
+		close(fd);
+	}
+	werrstr("");
+}
--- /sys/src/cmd/page/view.c	Thu Jul  7 05:38:25 2011
+++ /sys/src/cmd/page/view.c	Thu Jul  7 05:38:22 2011
@@ -317,6 +317,8 @@
 	midmenu.gen = 0;
 	midmenu.lasthit = Next;
 
+	if(doc->docname != nil)
+		setlabel(doc->docname);
 	showpage(page, &menu);
 	esetcursor(nil);