Retrieve historical LOC within a Git repo

gistfile1.txt

> git history-cloc 6
2019-06-30	20f3e2cf16972f9fa1a20e7e936ce9009442bad3	45280
2019-07-31	3eeea800e5230e77de8bba90cf7e5c84dee549fe	47312
2019-08-31	b765ca0d2477b25efd2720fc064162f7cafbcc59	47442
2019-09-30	bcca0795db6d46839021e8d2c51a6f1902a9cc09	48977
2019-10-31	513d85eccdf7131dcfbecd827859414c98e18348	45672
2019-11-30	e6c775cff9359322b0db232dd028cd253c9fd3c0	47877
>

git-history-cloc

#!/bin/bash

scriptname=$(basename ${0})
os=$(uname -s)

function usage {
    printf "\n%s [months]" ${scriptname}
    printf "\nPrints lines of code at the end of the last N months.\n"
    printf "Defaults to last 3 months. Maximum is 12 months.\n"
}

function past_date {
    current="${1}"
    interval="${2}"
    result="$(date -j -v -${interval}m -f %m/%d/%Y ${current} +%m/%d/%Y)"
    echo "$(date -j -v -1d -f %m/%d/%Y ${result} +%Y-%m-%d)"
}

function run_cloc {
    commit=${1}
    # Find top 5 most popular file extensions
    exts="$(find . -type f -not -ipath "./.git/*" | sed -n 's/..*\.//p' | sort | uniq -c | sort -r | head -n5 | awk '{print $2}' | tr '\n' ',')"
    ${cloc} --git --quiet --hide-rate --skip-uniqueness --include-ext="${exts}" ${commit} 2>&1 | grep -v recursion | grep -o -E 'SUM:([0-9 ])+' | tr -su ' ' ',' | cut -d , -f5
}

cloc=$(which cloc)

if [ "${cloc}" == "" ]; then
    if [ "${os}" == "Darwin" ]; then
        pkgmgr="brew install"
    else
        pkgmgr="[apt-get install|pacman -S]"
    fi
    printf "Please install 'cloc'. Ex: \"%s cloc\"\n" "${pkgmgr}"
    usage
    exit 1
fi

count=""

if [ $# -gt 0 ]; then
    case "${1}" in
        "-h")
            usage
            exit 0
            ;;
        "--help")
            usage
            exit 0
            ;;
        "0")
            count="3"
            ;;
        "1"|"2"|"3"|"4"|"5"|"6"|"7"|"8"|"9"|"10"|"11"|"12")
            count="${1}"
            ;;
        *)
            usage
            exit 1
    esac
fi

if [ "${count}" == "" ]; then
    count="3"
fi

count=$(expr ${count} - 1)
current=$(date +%m/1/%Y)
dates=""

while [ ${count} -gt -1 ]
do
    if [ "${dates}" == "" ]; then
        dates="$(past_date ${current} ${count})"
    else
        dates="${dates} $(past_date ${current} ${count})"
    fi
    count=$(expr ${count} - 1)
done

for d in ${dates}
do
    commit=$(git rev-list --until=\"${d}\" HEAD | head -n1)
    clocs="$(run_cloc ${commit})"
    printf "%s\t%s\t%d\n" ${d} ${commit} ${clocs}
done