Zip 압축파일 Header 구조
< zip 파일 구조 >
1. Local File Header(30byte: 가변값 제외)
local file header signature – 4 bytes – (0x04034b50) : 고유 값
version needed to extract – 2 bytes
general purpose bit flag – 2 bytes
compression method – 2 bytes
last mod file time – 2 bytes
last mod file date – 2 bytes
crc-32 – 4 bytes
compressed size – 4 bytes
uncompressed size – 4 bytes
file name length – 2 bytes
extra field length – 2 bytes
file name (variable size)
extra field (variable size)
2. Central File Header(46byte: 가변값 제외)
central file header signature – 4 bytes – (0x02014b50) : 고유 값
version made by – 2 bytes
version needed to extract – 2 bytes
general purpose bit flag – 2 bytes
compression method – 2 bytes
last mod file time – 2 bytes
last mod file date – 2 bytes
crc-32 – 4 bytes
compressed size – 4 bytes
uncompressed size – 4 bytes
file name length – 2 bytes
extra field length – 2 bytes
file comment length – 2 bytes
disk number start – 2 bytes
internal file attributes – 2 bytes
external file attributes – 4 bytes
relative offset of local header 4 bytes
file name (variable size)
extra field (variable size)
file comment (variable size)
3. End Header(22byte: comment 제외)
end of central dir signature – 4 bytes – (0x06054b50) : 고유값
number of this disk – 2 bytes
number of the disk with the start of the central directory – 2 bytes
total number of entries in the central directory on this disk – 2 bytes
total number of entries in the central directory – 2 bytes
size of the central directory – 4 bytes
offset of start of central directory with respect to the starting disk number – 4 bytes
.ZIP file comment length – 2 bytes
.ZIP file comment (variable size)
*참고 사이트:
zip 알고리즘(Deflate) – http://ko.wikipedia.org/wiki/DEFLATE, http://en.wikipedia.org/wiki/DEFLATE
LZ 77 알고리즘 – http://home.postech.ac.kr/~ehoto/lz77.htm
ZIP File Format Specification – http://www.pkware.com/documents/casestudies/APPNOTE.TXT
zlib Home page – http://www.zlib.net/
Winimage.com minizip – http://www.winimage.com/zLibDll/minizip.html
Zlib Library Manual – http://kaistizen.net/project/Zip/Index.htm
Zlib 활용(글쓴이: 윤상배) – http://www.joinc.co.kr/modules/moniwiki/wiki.php/article/zlib_prog
