This is a tiny tool for Linux which computes a sha256 hash of 
a file and stores it in an extended attribute. It can be used
to verify file integrity, find duplicates, detect changes, etc.

(Note that it is not intended to detect malicious changes to
a file, because an attacker who has access to the file could
also change the cached hash.)



Compute hash if not up-to-date and store it in the attribute,
then show the hash and status:

hashcache -scu file


To quickly find files that have changed, recompute hash
if the file may have changed and check:

hashcache -ci file


To detect file system errors, always recompute the hash
and check integrity:

hashcache -ri file


Delete the hash:

hashcache -d file