Simple dotenv wrapper on Bash (replace dotenv gem).

app-env

#!/usr/bin/env bash
#
#/ Usage: app-env [[-e <DOTENV_FILE>]... ] [[-s <SOURCE_FILE>]... ] [--] <command> [<args>...]
#/        app-env [-h|--help]
#/
#/ Executes a given command with environment variables loaded from dotenv files.
#/ Dotenv files are executed in current shell context, wrapped with `set -e'.
#/ Source files, which are set with the `-s' flag will be included after `set +e'
#/ It is possible to provide several files, just by using flags as many tymes as you need.
#/
#/ Options:
#/    -e <DOTENV_FILE>          dotenv files (default ".env.local")
#/    -s <SOURCE_FILE>          source files
#/    -v                        verbose output
#/    --                        separator
#/    -h, --help                show this text
#/
#/ Note: requires bash version >= 4

if [[ "${BASH_VERSINFO}" -lt 4 ]]; then
  echo "!! Required bash >= 4" >> /dev/stderr
  exit 1
fi

declare _verbose;
declare -a dotenv_files=()
declare -a source_files=()
declare APP_ENV_PATH

ae__show_help() {
  cat < "$0" | grep '^#/' | cut -c4-; exit "${1:-0}"
}

while true; do
  case "$1" in
    -h|--help) ae__show_help 0; break;;
    -v|--verbose) _verbose=1; shift 1;;
    -e) dotenv_files+=("$2"); shift 2;;
    -s) source_files+=("$2"); shift 2;;
    --) shift 1; break;;
    *)  break;;
  esac
done

[[ -z "$1" ]] && show_help 1

_info() {
	test -n "${_verbose}" && echo "${1}" >> /dev/stderr
}

_fail() {
	echo "${1}" >> /dev/stderr; exit 1
}

if [[ $(uname -s) = "Darwin" ]]; then
  ae__q() { echo -n "${1@Q}"; }
else
  ae__q() { printf "%q" "$1"; }
fi

ae__quote() {
  local -a _args=()
  for arg in "$@"; do _args+=($(ae__q "$arg")); done
  echo "${_args[*]}"
}

ae__append_default_dotenv() {
  local default_dotenv="${PWD}"/.env
  [[ -e "${default_dotenv}" ]] && dotenv_files+=("${default_dotenv}")
}

ae__include_dotenv_files() {
  _info "$ set -a"; set -a
  for source in "${dotenv_files[@]}"; do
    if [[ -e "${source}" ]]; then
      _info "$ . '${source}'"; source "${source}"
      source_real=$(realpath "${source}")
      if [[ -e "${APP_ENV_PATH}" ]]; then
        APP_ENV_PATH="${source_real}"
      else
        APP_ENV_PATH="${source_real}:$APP_ENV_PATH"
      fi
    else
      _fail "Can't read ${source}"
    fi
  done
  if [[ -n "${APP_ENV_PATH}" ]]; then
    _info "$ export APP_ENV_PATH=${APP_ENV_PATH}";  export APP_ENV_PATH
  fi
  _info "$ set +a"; set +a
}

declare dotenv_command
ae__include_source_files() {
  for source in "${source_files[@]}"; do
    if [[ -e "${source}" ]]; then
      echo -n "source ${source}; "
    else
      _fail "Can't read ${source}"
    fi
  done
  echo -n "exec ${dotenv_command}"
}

[[ "${#dotenv_files[@]}" -eq 0 ]] && ae__append_default_dotenv
dotenv_command=$(ae__quote "$@")
[[ "${#dotenv_files[@]}" -gt 0 ]] && ae__include_dotenv_files
dotenv_command=$(ae__include_source_files)
_info "$ ${dotenv_command}"
eval "${dotenv_command}"

install.sh

mkdir -p bin
\curl https://gist.github.com/estum/0b32147f644fbfbd5462a8b6a12b82c5/raw/app-env > bin/app-env
chmod a+x bin/app-env

Quick install executable to bin dir inside your project:

\curl -L https://git.io/vHVxf | bash -s stable