git-root: finds git root directory without using git executable (POSIX compliant shell script)

git-root

#!/bin/sh

#$1: Path to child directory
git_root_recurse_parent() {
    # Check if cwd is a git root directory
    if [ -d .git/objects -a -d .git/refs -a -f .git/HEAD ] ; then
        pwd
        return 0
    fi

    # Check if recursion should end (typically if cwd is /)
    if [ "${1}" = "$(pwd)" ] ; then
        return 1
    fi

    # Check parent directory in the same way
    local cwd=$(pwd)
    cd ..
    git_root_recurse_parent "${cwd}"
}

git_root_recurse_parent