Fingerprint or Digest files - SHELL

FingerPrint

# Create first
find -type f -name "*.php" -exec md5sum "{}" + > checklist.chk

# Save on remote server or your computer, it best if your create a hook on git or mercurial to create this on the fly.
# Later on or in cron you must check if all is good.
# Can you even do remove write permission,
# chmod a-w checklist.chk

# This will give you the following pattern: 
# file: OK
md5sum -c checklist.chk