home *** CD-ROM | disk | FTP | other *** search
-
- 31 Mar 89
- Format of file headers within .LZH archives:
-
- Byte 0: No. bytes in header - 2 (0 = end of file)
- 1: Checksum of remaining bytes (counted by byte 0)
- 2-6: ASCII compression type:
- '-lh0-' = no compression
- '-lh1-' = LHARC compression
- (presumably other valid types used by
- the separate LARC program?)
- 7-10: Comressed file size \ (low byte
- 11-14: Original file length / first)
- 15-16: File time \ (INT 21H,
- 17-18: File date / function 57H)
- 19-20: File attributes (INT 21H, function 43H)
- 21: No. bytes in path/file name (n)
- 22...: Path/file name (n bytes)
- 22+n: CRC-16 (2 bytes, optional; requires byte 0 - byte 21 = 22)
- 22+n = Header length, if no CRC (generated by ???)
- 24+n = Header length, if CRC
-
-
- Notes:
-
- (1) Above inferred by manual inspection and confirmed by disassembly
- of LHARC10E self-extraction code, except for bytes 19-20, which are
- not used by self-extraction code.
-
- (2) Maximum path/file name length = 233 bytes (235 bytes, if no CRC),
- given max. byte 0 count = 255
-
- (3) CRC-16 polynomial identical to that used by .ARC archives.
-
- - Robert A. Freed
- Newton Centre, MA
-
-
-