A .vpk (Valve Pak) incremental extractor. Check the CRCs inside the .vpk against a list of know CRCs.
go build vpk_extract
or
SET GOOS=linux&&SET GOARCH=amd64&&go build vpk_extract
vpk_extract [-c COMMAND] -i INPUT_VPK.vpk -o OUTPUT_FOLDER [GLOB_PATTERNS]
COMMAND is either extract or crc and default to extract if omitted
GLOB_PATTERNS default to * if omitted
-i is required is COMMAND is extract
Extract everything from a .vpk
vpk_extract -i INPUT_VPK.vpk -o OUTPUT_FOLDER
Extract only the models and materials subdirectories
vpk_extract -i INPUT_VPK.vpk -o OUTPUT_FOLDER models/* materials/*
Compute the CRC of existing files in the output folder
vpk_extract -c crc -o OUTPUT_FOLDER