gzip

Author: Vincent Ecuyer
Date: 4-Feb-2013
File: %gzip.r

Contents:

1. Purpose

Creates gzip archives, using the rebol compress command.

2. Usage

Compresses a string series into a gzip encoding, and returns the binary result.

gzip data /name file

• data (any-string! binary!) - Data to compress.
• /name - Specifies a filename. (optional : default filename is the same as the archive's without the .gz extension)
• file (with /name) - The filename to use in archive.

3. Examples

REBOL 2:

my-data: #{........}
write/binary %test.gz gzip/name my-data %my-file.txt

REBOL 3:

my-data: #{........} 
write %test.gz gzip/name my-data %my-file.txt

4. Comment

COMPRESS uses a zlib compatible format - always with deflate algorithm, 32k window size, max compression and no dictionary - followed by checksum (4 bytes) and uncompressed data length (4 bytes).

For REBOL 2.x, this module uses a precalculated crc table, and for REBOL 3.x, it uses the available 'crc32 checksum method - r3 compress/gzip is bugged (wrong checksum), so it isn't used.