xref: /plan9/sys/src/cmd/gzip/gzip.h (revision 7dd7cddf99dd7472612f1413b4da293630e6b1bc)
1 /*
2  * gzip header fields
3  */
4 enum
5 {
6 	GZMAGIC1	= 0x1f,
7 	GZMAGIC2	= 0x8b,
8 
9 	GZDEFLATE	= 8,
10 
11 	GZFTEXT		= 1 << 0,		/* file is text */
12 	GZFHCRC		= 1 << 1,		/* crc of header included */
13 	GZFEXTRA	= 1 << 2,		/* extra header included */
14 	GZFNAME		= 1 << 3,		/* name of file included */
15 	GZFCOMMENT	= 1 << 4,		/* header comment included */
16 	GZFMASK		= (1 << 5) -1,		/* mask of specified bits */
17 
18 	GZXFAST		= 2,			/* used fast algorithm, little compression */
19 	GZXBEST		= 4,			/* used maximum compression algorithm */
20 
21 	GZOSFAT		= 0,			/* FAT file system */
22 	GZOSAMIGA	= 1,			/* Amiga */
23 	GZOSVMS		= 2,			/* VMS or OpenVMS */
24 	GZOSUNIX	= 3,			/* Unix */
25 	GZOSVMCMS	= 4,			/* VM/CMS */
26 	GZOSATARI	= 5,			/* Atari TOS */
27 	GZOSHPFS	= 6,			/* HPFS file system */
28 	GZOSMAC		= 7,			/* Macintosh */
29 	GZOSZSYS	= 8,			/* Z-System */
30 	GZOSCPM		= 9,			/* CP/M */
31 	GZOSTOPS20	= 10,			/* TOPS-20 */
32 	GZOSNTFS	= 11,			/* NTFS file system */
33 	GZOSQDOS	= 12,			/* QDOS */
34 	GZOSACORN	= 13,			/* Acorn RISCOS */
35 	GZOSUNK		= 255,
36 
37 	GZCRCPOLY	= 0xedb88320UL,
38 
39 	GZOSINFERNO	= GZOSUNIX,
40 };
41