Simple git pre-commit hook for detecting a do-not-commit token (e.g. "NOSHARE").

pre-commit

#!/bin/sh
#set -x

git diff-index --cached --quiet HEAD
_ANY=$?

if ((0 == $_ANY)); then
    exit 0
fi

# corpus has filename context
_CORPUS=`git diff --cached | grep '^+\(++\|.*NOSHARE\)'`
_TOKEN_FOUND=`echo "$_CORPUS" | grep NOSHARE`

if [ "" == "$_TOKEN_FOUND" ]; then
    echo "Commit clean, proceeding..."
    exit 0
else
    echo "$_CORPUS"
    echo '"NOSHARE" found, aborting commit...'
    exit 1
fi