git-last-commit-to-file

#!/bin/sh
set -e

usage () {
    echo "usage: git last-commit-to-file [-h] <file> [<file> ...]" >&2
    echo >&2
    echo "Returns the SHA of the commit that last touched the given file." >&2
    echo "If multiple files are given, will return the SHA that most-recently" >&2
    echo "changed _any_ of the files." >&2
    echo >&2
    echo "Options:" >&2
    echo "-h    Show this help" >&2
}

while getopts h flag; do
    case "$flag" in
        h) usage; exit 2;;
    esac
done
shift $(($OPTIND - 1))

if [ $# -lt 1 ]; then
    usage
    exit 2
fi

git log -1 --format='%H' -- "$@" 2>/dev/null