Synchronize content of two copies of the same git repository. Only tracked files are are copied. Warning - I can't use bash.

git-sync.sh

#! sh

set -e

target="$1"

if [ -z  "$target" ]
then
    echo "Please provide the target directory."
    exit -1
else
    target=$(realpath "$target")
fi

if [[ ! -d "$target" ]]
then
    echo "Target directory '$target' does not exist. Initialize it with a copy of this repo."
fi

if [ "$target" == $(pwd) ]
then
    echo "Trying to sync with current directory. Exiting..."
    exit 0
fi

commit=$(git log -1 --pretty=%h)

( cd "$target" && git reset --hard >/dev/null 2>&1 && git checkout "$commit" >/dev/null 2>&1 || \
    ( echo "Fetching latest changes..." && git fetch && git checkout "$commit" >/dev/null 2>&1 || echo "Revision not found!"; exit -2 ) )

git diff HEAD | ( cd "$target" && git apply - )

if [[ $@ == *-v* ]]
then
    echo "Checked out $commit at $target"
    echo ""
    echo "Synced files:"
    git diff HEAD --name-only
fi