View source for LIF (Knowledge Dynamics)

{{FormatInfo
|formattype=electronic
|subcat=Archiving
|extensions={{ext|lif}}
|released=≤1989
}}
'''.LIF''' is an installer-archive format, apparently associated with ''INSTALL'' for DOS, by Knowledge Dynamics Corporation. See [[RED (Knowledge Dynamics)]] for more information about INSTALL.

This article covers the LIF format that begins with a string of ASCII-encoded hex digits. Note that the presumed successor format, [[RED (Knowledge Dynamics)|RED]], also sometimes uses the .LIF filename extension.

== Format details ==
=== File structure ===
A LIF file consists of a sequence of member file segments. Each member consists of a 54-byte header, then the file data, which is usually compressed.

The header starts with 34 bytes of ASCII-encoded hex digits. A filename follows. The bytes at offset 8 through 15 encode the compressed data size, which is needed to locate the next member.

=== Header structure ===
The 54-byte member header seems to have the following structure:

{| class="wikitable"
! Offset !! Size (in file) !! Size (decoded) !! Description
|-
|0 || 8 || 4 || [[MS-DOS date/time|DOS date, time]]
|-
|8 || 8 || 4 || Compressed size
|-
|16 || 8 || 4 || Original size
|-
|24 || 4 || 2 || CRC of compressed data. The CRC algorithm seems to be the one named "CRC-16/IBM-3740" by the [https://reveng.sourceforge.io/crc-catalogue/16.htm CRC RevEng catalogue] (a slight variant of [[CRC-16#CRC-16/XMODEM|CRC-16/XMODEM]]).
|-
|28 || 4 || 2 || CRC of uncompressed data
|-
|32 || 2 || 1 || Compression method
|-
|34 ||colspan="2"| 20 || Filename, NUL-padded. This 20-byte field might use as little as 12 bytes for the filename, with the remaining bytes having an undetermined purpose.
|}

=== Compression methods ===
Method 1 is uncompressed. Method 2 is [[LZW]], possibly the same as [[Zoo]]. Method 3 has been observed, but is unidentified.

FWIW, there is a "Knowledge Dynamics LZW COMPRESSOR" format that was used in some video games: [https://moddingwiki.shikadi.net/wiki/CC_Format], via [https://moddingwiki.shikadi.net/wiki/Knowledge_Dynamics_LZW_COMPRESSOR]. However, it seems different from the LZW compression used in LIF.

== Sample files ==
* {{CdTextfiles|pier02/046a/dosdrvrs.zip|dosdrvrs.zip}} → *.LIF
* {{CdTextfiles|ccbwindows93/DEMOS/FINDEMO1.ZIP|FINDEMO1.ZIP}} → *.LIF
* {{CdTextfiles|cica/cica9207/WIN3/DEMO/ORIGINWM.ZIP|ORIGINWM.ZIP}} → *.LIF