ref: faa625a1d5ab47ac0438b2cea5b2bde1ea747b8b
dir: /sys/src/cmd/gzip/gzip.h/
/*
* gzip header fields
*/
enum
{
GZMAGIC1 = 0x1f,
GZMAGIC2 = 0x8b,
GZDEFLATE = 8,
GZFTEXT = 1 << 0, /* file is text */
GZFHCRC = 1 << 1, /* crc of header included */
GZFEXTRA = 1 << 2, /* extra header included */
GZFNAME = 1 << 3, /* name of file included */
GZFCOMMENT = 1 << 4, /* header comment included */
GZFMASK = (1 << 5) -1, /* mask of specified bits */
GZXFAST = 2, /* used fast algorithm, little compression */
GZXBEST = 4, /* used maximum compression algorithm */
GZOSFAT = 0, /* FAT file system */
GZOSAMIGA = 1, /* Amiga */
GZOSVMS = 2, /* VMS or OpenVMS */
GZOSUNIX = 3, /* Unix */
GZOSVMCMS = 4, /* VM/CMS */
GZOSATARI = 5, /* Atari TOS */
GZOSHPFS = 6, /* HPFS file system */
GZOSMAC = 7, /* Macintosh */
GZOSZSYS = 8, /* Z-System */
GZOSCPM = 9, /* CP/M */
GZOSTOPS20 = 10, /* TOPS-20 */
GZOSNTFS = 11, /* NTFS file system */
GZOSQDOS = 12, /* QDOS */
GZOSACORN = 13, /* Acorn RISCOS */
GZOSUNK = 255,
GZCRCPOLY = 0xedb88320UL,
GZOSINFERNO = GZOSUNIX,
};