Locate the git commit of a file that contains a specific MD5 checksum

gitfind

#!/bin/bash
#
# Find a specific version of a file in the current directory by
# searching back through Git commit history. The file version is
# identified by the MD5 checksum.
#

declare -r check_file="${1}"
declare -r target_hash="${2}"

declare -r orig_commit="$(git rev-parse HEAD)"
declare checksum

if [ -z "${js_hash}" -a -z "${target_hash}" ]
then
    echo "Usage: $(basename "${0}") FILE HASH" 1>&2
    exit 1
elif [ ! -f "${js_hash}" ]
then
    echo "Error: ${check_file} not found."
    exit 1
fi

for commit in $(git log --pretty=oneline | cut -d ' ' -f 1)
do
    git checkout --quiet "${commit}"

    if [ ! -f "${check_file}" ]
    then
        echo "${check_file} no longer found"
        break
    fi
    checksum="$(md5sum "${check_file}" | cut -d ' ' -f 1)"
    if [ "${checksum}" = "${target_hash}" ]
    then
        echo "Target hash found in commit ${commit}"
        break
    else
        echo "${checksum} != ${target_hash}"
    fi
done
git checkout --quiet "${orig_commit}"