git-branch-dates

#!/usr/bin/env bash
set -euo pipefail

sort_mode="age"
refs="refs/heads"

while [[ $# -gt 0 ]]; do
  case "$1" in
    -n|--name) sort_mode="name" ;;
    -a|--age)  sort_mode="age" ;;
    -r|--remote|--remotes) refs="refs/remotes" ;;
    -h|--help)
      cat <<'EOF'
Usage: git-branch-date [--name|--age] [--remote]

  --name    sort by branch name
  --age     sort by last modification time (default)
  --remote  show remote-tracking branches
EOF
      exit 0
      ;;
    *)
      echo "Unknown option: $1" >&2
      exit 2
      ;;
  esac
  shift
done

case "$sort_mode" in
  name) sort_key="refname" ;;
  age)  sort_key="-committerdate" ;;
esac

now=$(date +%s)

red=$'\033[31m'
green_bold=$'\033[1;32m'
yellow=$'\033[33m'
cyan=$'\033[36m'
dim=$'\033[2m'
reset=$'\033[0m'

git for-each-ref "$refs" \
  --sort="$sort_key" \
  --format='%(HEAD)|%(refname:short)|%(committerdate:unix)|%(committerdate:short)|%(committerdate:relative)' |
while IFS='|' read -r head branch ts shortdate rel; do
  age_days=$(( (now - ts) / 86400 ))

  if [[ "$head" == "*" ]]; then
    marker="*"
    bcolor="$green_bold"
  else
    marker=" "
    bcolor="$red"
  fi

  printf '%s %b%-56s%b  %b%6dd%b  %b%s%b\n' \
    "$marker" \
    "$bcolor" "$branch" "$reset" \
    "$yellow" "$age_days" "$reset" \
    "$dim" "$shortdate" "$reset"
#   printf '%s %b%-45s%b  %b%6dd%b  %b%-10s%b  %b%s%b\n' \
#     "$marker" \
#     "$bcolor" "$branch" "$reset" \
#     "$yellow" "$age_days" "$reset" \
#     "$dim" "$shortdate" "$reset" \
#     "$cyan" "$rel" "$reset"
done