add gzip, bzip2

'

src/cmd/gzip/zip.h

@@ -0,0 +1,83 @@
+typedef struct ZipHead	ZipHead;
+
+enum
+{
+	/*
+	 * magic numbers
+	 */
+	ZHeader		= 0x04034b50,
+	ZCHeader	= 0x02014b50,
+	ZECHeader	= 0x06054b50,
+
+	/*
+	 * "general purpose flag" bits
+	 */
+	ZEncrypted	= 1 << 0,
+	ZTrailInfo	= 1 << 3,	/* uncsize, csize, and crc are in trailer */
+	ZCompPatch	= 1 << 5,	/* compression patched data */
+
+	ZCrcPoly	= 0xedb88320,
+
+	/*
+	 * compression method
+	 */
+	ZDeflate	= 8,
+
+	/*
+	 * internal file attributes
+	 */
+	ZIsText		= 1 << 0,
+
+	/*
+	 * file attribute interpretation, from high byte of version
+	 */
+	ZDos		= 0,
+	ZAmiga		= 1,
+	ZVMS		= 2,
+	ZUnix		= 3,
+	ZVMCMS		= 4,
+	ZAtariST	= 5,
+	ZOS2HPFS	= 6,
+	ZMac		= 7,
+	ZZsys		= 8,
+	ZCPM		= 9,
+	ZNtfs		= 10,
+
+	/*
+	 * external attribute flags for ZDos
+	 */
+	ZDROnly		= 0x01,
+	ZDHidden	= 0x02,
+	ZDSystem	= 0x04,
+	ZDVLable	= 0x08,
+	ZDDir		= 0x10,
+	ZDArch		= 0x20,
+
+	ZHeadSize	= 4 + 2 + 2 + 2 + 2 + 2 + 4 + 4 + 4 + 2 + 2,
+	ZHeadCrc	= 4 + 2 + 2 + 2 + 2 + 2,
+	ZTrailSize	= 4 + 4 + 4,
+	ZCHeadSize	= 4 + 2 + 2 + 2 + 2 + 2 + 2 + 4 + 4 + 4 + 2 + 2 + 2 + 2 + 2 + 4 + 4,
+	ZECHeadSize	= 4 + 2 + 2 + 2 + 2 + 4 + 4 + 2,
+};
+
+/*
+ * interesting info from a zip header
+ */
+struct ZipHead
+{
+	int	madeos;			/* version made by */
+	int	madevers;
+	int	extos;			/* version needed to extract */
+	int	extvers;
+	int	flags;			/* general purpose bit flag */
+	int	meth;
+	int	modtime;
+	int	moddate;
+	ulong	crc;
+	ulong	csize;
+	ulong	uncsize;
+	int	iattr;
+	ulong	eattr;
+	ulong	off;
+	char	*file;
+};