snapshot target

Add Makefile target to create snapshot file.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
diff --git a/Makefile b/Makefile
index 6c976dd..de04176 100644
--- a/Makefile
+++ b/Makefile
@@ -59,6 +59,10 @@
 	install -m 0755 -d $(DESTDIR)$(MANDIR)/man3
 	install -m 0644 $(shell find man/man3 -maxdepth 1 -type f) $(DESTDIR)$(MANDIR)/man3
 
+snapshot:
+	echo "static const char SNAPSHOT[] = \""`date +%y%m%d`"\";" \
+		> include/SNAPSHOT.h
+
 clean:
 	rm -f cscope.*
 	@for i in $(SUBDIRS) doc; \
diff --git a/include/SNAPSHOT.h b/include/SNAPSHOT.h
index dde2804..cdeb206 100644
--- a/include/SNAPSHOT.h
+++ b/include/SNAPSHOT.h
@@ -1 +1 @@
-static char SNAPSHOT[] = "071016";
+static const char SNAPSHOT[] = "071221";