git-get-date

git-get-date

#!/usr/bin/env bash
#
# git-get-date 
# Copyright (c) 2019 Koichi OKADA. All rights reserved.
# This script is distributed under the MIT license.
#

function usage ()
{
  cat <<-EOD
	Usage: git get-date [<options>] [<revisions> ...]

	    -a, --author          Show author date (default)
	    -c, --commit          Show commit date
	EOD
}

function git-get-date ()
{
  local i TARGET=AuthorDate REV=() DATE
  
  for i; do
    case "$i" in
      -a|--author) TARGET=AuthorDate ;;
      -c|--commit) TARGET=CommitDate ;;
      -h|--help) usage; exit ;;
      -*) echo "Error: Unknown option: $i"; exit 1 ;;
      *) REV+=( "$i" ) ;;
    esac
  done
  
  for i in "${REV[@]:-HEAD}"; do
    readarray -t TIME < <(
      git log --pretty=fuller -1 "$i" \
      | awk -vTARGET="$TARGET" '$1==TARGET":"&&(($1="")||1)'
    )
    if [ -z "$TIME" ]; then
      echo "Error: Faild to get $TARGET for $i" >&2
    else
      ruby -r Time -e 'puts Time.parse(ARGV[0])' "$TIME"
    fi
  done
}

git-get-date "$@"