Tell file how to detect the .DS_Store files
created by OS X's Finder via a 4-byte magic
number 4 bytes into the file.

I'd originally submitted this against an old
version of file.c; now updated.

Reference: /n/sources/patch/applied/file-.ds_store
Date: Tue Aug 18 05:38:44 CES 2009
Signed-off-by: a@9srv.net

--- /sys/src/cmd/file.c	Tue Aug 18 05:29:17 2009
+++ /sys/src/cmd/file.c	Tue Aug 18 05:37:37 2009
@@ -639,6 +639,7 @@
 	256*1024, 0xe7a5e4a9, 0xFFFFFFFF, "venti arenas partition\n", OCTET,
 	256*1024, 0xc75e5cd1, 0xFFFFFFFF, "venti index section\n", OCTET,
 	128*1024, 0x89ae7637, 0xFFFFFFFF, "fossil write buffer\n", OCTET,
+	4, 0x31647542, 0xFFFFFFFF, "OS X DS Store\n", OCTET,
 };
 
 int