git-branch-info

#!/usr/bin/bash

script_dir="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" &> /dev/null && pwd)"
script_name="$(basename "${BASH_SOURCE[0]}")"

unmerged=
merged=
while getopts "um" o; do
  case "$o" in 
    u) unmerged=1 ;;
    m) merged=1 ;;
    *) ;;
  esac
done
shift $((OPTIND-1))

if [ -z "$1" ] ; then
cat 1>&2 <<- EOM
	usage: $script_name [flags] <trunk> [<trunk1> ...]

  flags:
      -u  only show branches where ahead > 0

	description:
      For each branch in the local repo, find the # of commits behind and ahead of <trunk>.  It then
      outputs a list of branches with at least one commit ahead of <trunk>, sorted by increasing
      number of commits behind <trunk>.

      If more than one trunk (positional argument) is given, branches are excluded from the output if
      they have been merged into any of the trunks.
EOM
  exit 1
fi

# dependencies
git_behind="${script_dir}"/git-behind
git_ahead="${script_dir}"/git-ahead
if [ ! -x "$git_behind" ]; then
  echo "FATAL: git-behind not available in \$PATH" 1>&2
  exit 1
fi
if [ ! -x "$git_ahead" ]; then
  echo "FATAL: git-ahead not available in \$PATH" 1>&2
  exit 1
fi

readarray -t branches <<< "$(git branch | awk '{ print $1 }' | sed '/origin\|*\|+/d')"
for b in "${branches[@]}" ; do
  # echo ">branch: ${b}" 1>&2
  min_behind=4294967295
  min_ahead=4294967295
  for trunk in "$@" ; do
    behind="$("$git_behind" "${trunk}" "${b}")"
    if [ "${min_behind}" -gt "${behind}" ] ; then
      min_behind="${behind}"
    fi
    ahead="$("$git_ahead" "${trunk}" "${b}")"
    if [ "${min_ahead}" -gt "${ahead}" ] ; then
      min_ahead="${ahead}"
    fi
  done
  if [ -z "$unmerged" ] && [ -z "$merged" ] ; then
    author="$(git cat-file -p "$(git rev-parse "$b")" | sed -nE 's/author (.*?) <.*/\1/p')"
    ahead_list+=("$(printf "%6d %6d %-25s %s\n" "$behind" "$ahead" "\"$author\"" "$b")")
  elif [ -n "$merged" ] && [ "${min_ahead}" -eq 0 ] ; then
    author="$(git cat-file -p "$(git rev-parse "$b")" | sed -nE 's/author (.*?) <.*/\1/p')"
    ahead_list+=("$(printf "%6d %6d %-25s %s\n" "$behind" "$ahead" "\"$author\"" "$b")")
  elif [ -n "$unmerged" ] && [ "${min_ahead}" -ne 0 ] ; then
    author="$(git cat-file -p "$(git rev-parse "$b")" | sed -nE 's/author (.*?) <.*/\1/p')"
    ahead_list+=("$(printf "%6d %6d %-25s %s\n" "$behind" "$ahead" "\"$author\"" "$b")")
  fi
done
if [ "${#ahead_list[@]}" -gt 0 ]; then
  IFS=$'\n'; ahead_list=("$(sort -n -k1 <<< "${ahead_list[*]}")"); IFS=
  # readarray -t ahead_list <<< "$(sort -n -k1 <<< "${ahead_list[*]}")"
  printf "%6s %6s %-25s %s\n" "behind" " ahead" "author      " "branch"
  for row in "${ahead_list[@]}"; do
    echo "$row"
  done
fi