Git date and SHA from local repo

git-metadata.sh

#!/usr/bin/env bash
#
# Display Git metadata useful for other scripts
#

# ------------------------------------
# Convert UNIX timestamp (seconds since epoch UTC) to YYYY-MM-DDTHH:MM:SSZ
# ------------------------------------
function unix_to_iso() {
  declare ts=${1}

  declare formatOutput="+%FT%TZ"
  case $(uname -s) in
    ( Darwin )
       TZ=UTC date -j -f "%s" $ts $formatOutput
      ;;
    ( Linux )
      TZ=UTC date -d @$ts $formatOutput
      ;;
  esac
}

# ------------------------------------
# Get the most recently updated branch
# ------------------------------------
latest_branch() {
  ref=$(git for-each-ref \
    --count=1 \
    --sort='-committerdate' \
    --format='%(refname:short)' \
    '**')
  echo ${ref#*/}  # strip origin/ off
}

# ------------------------------------
# Get the most recently created tag
# ------------------------------------
latest_tag() {
  {
    # annotated tags
    git for-each-ref \
      --count=1 \
      --sort='-taggerdate' \
      --format='%(taggerdate:raw) %(refname:short)' \
      'refs/tags' ;
    # lightweight tags
      git for-each-ref \
        --count=1 \
        --sort='-committerdate' \
        --format='%(committerdate:raw) %(refname:short)' \
        'refs/tags' ;
  } | sort -n |tail -1 |awk '{ print $3 }'
}

# ------------------------------------
# Get the git metadata for the current project
# ------------------------------------
declare -a versionSplit=( $(TZ=UTC git log -n 1 --pretty="%ct %h %H") )
versionDate=$(unix_to_iso ${versionSplit[0]})
versionSHA=${versionSplit[1]}
versionSHALong=${versionSplit[2]}


cat <<EOF
BRANCH=$(git rev-parse --abbrev-ref HEAD)
COMMIT_DATE=$versionDate
SHA_SHORT=$versionSHA
SHA=$versionSHALong
EOF