Simple script for changing Homebrew installed PHP versions

sphp

#!/usr/bin/env bash
################################################################################
#
# MacOS Homebrew-based PHP version switcher.
#
################################################################################

# Define read-only script variables
# -------------------------------------------------------------------------------
declare -r SPHP_BREW_PREFIX="$(brew --prefix | sed 's#/#\\\/#g')"
declare -r SPHP_BREW_ARRAY=("5.6" "7.0" "7.1" "7.2" "7.3")
declare -r SPHP_PHP_ARRAY=("php@5.6" "php@7.0" "php@7.1" "php@7.2" "php@7.3")
declare -r SPHP_PROFILE="${HOME}/.zshrc"
declare SPHP_INSTALLED_ARRAY=()


# Program usage
# -------------------------------------------------------------------------------
function _usage() {
  echo -e "
$(tput bold)Usage:$(tput sgr0)
  sphp [options...] <php_version>

$(tput bold)Options:$(tput sgr0)
  -l, --list        List available PHP versions
  -h, --help        Display this help and exit
"
}

# Available versions
# -------------------------------------------------------------------------------
function _versions() {
  echo -e "Available versions of PHP: ${SPHP_BREW_ARRAY[@]}"
}

# Trap Function
# -------------------------------------------------------------------------------
# Any actions that should be taken if the script is prematurely
# exited. Always call this function at the top of your script.
# -------------------------------------------------------------------------------
function _trap() {
  exit 1
}

# Exit Function
# -------------------------------------------------------------------------------
# Non-destructive exit for when script exits naturally.
# Add this function at the end of the script.
#
# Arguments:
#   $1 (optional) - Exit code (defaults to 0)
# -------------------------------------------------------------------------------
function clean_exit() {
  trap - INT TERM EXIT
  exit ${1:-0}
}

# Parse Program Options
# -------------------------------------------------------------------------------
function parse_options() {
  # iterate over options
  # breaking -ab into -a -b when needed and --foo=bar into --foo bar
  local opt_string=h
  unset options
  while (($#)); do
    case $1 in
      # if option is of type -ab
      -[!-]?*)
        # loop over each character starting with the second
        for ((i = 1; i < ${#1}; i++)); do
          c=${1:i:1}
          options+=("-$c") # add current char to options
          # if option takes a required argument, and it's not the last char make
          # the rest of the string its argument
          if [[ "${opt_string}" == *"$c:"* && ${1:i+1} ]]; then
            options+=("${1:i+1}")
            break
          fi
        done
        ;;
      # if option is of type --foo=bar
      --?*=*) options+=("${1%%=*}" "${1#*=}") ;;
      # add --endopts for --
      --) options+=(--endopts) ;;
      # otherwise, nothing special
      *) options+=("${1}") ;;
    esac
    shift
  done
  set -- "${options[@]}"
  unset options

  # read the options and set stuff
  while [[ ${1-} == -?* ]]; do
    case $1 in
      -h | --help)
        _usage >&2
        clean_exit
        ;;
      -l | --list)
        _versions >&2
        clean_exit
        ;;
      --endopts)
        shift
        break
        ;;
      *)
        echo "sphp: invalid option '${1}'"
        exit 1
      ;;
    esac
    shift
  done
  # store the remaining user input as arguments
  ARGS+=("$@")
}

# Main Program
# -------------------------------------------------------------------------------
function main_run() {
  local REQUESTED_VERSION="php@${ARGS}"

  if [[ -z "${ARGS}" ]]; then
    _usage
    clean_exit
  fi

  # check that ZSH is being used
  if [ -z "`$SHELL -c 'echo $ZSH_VERSION'`" ]; then
    echo "sphp: sorry, this script assumes you are using ZSH."
    clean_exit 1
  fi

  # get which versions the user has installed
  for i in ${SPHP_PHP_ARRAY[*]}; do
    if [[ -n "$(brew ls --versions "${i}")" ]]; then
      SPHP_INSTALLED_ARRAY+=("${i}")
    fi
  done

  # check the specified version is both supported and installed
  if [[ " ${SPHP_PHP_ARRAY[*]} " == *"${REQUESTED_VERSION}"* ]] && [[ "${SPHP_INSTALLED_ARRAY[*]}" == *"${REQUESTED_VERSION}"* ]]; then
    echo "Switching to ${REQUESTED_VERSION}"

    echo "Stopping brew services..."
    for i in ${SPHP_INSTALLED_ARRAY[@]}; do
      brew unlink "${i}" >/dev/null 2>&1
      brew services stop "${i}" >/dev/null 2>&1
    done
    brew link --force "${PHP_VERSION}" >/dev/null 2>&1

    echo "Switching your shell variables..."
    if [[ ! -f "${SPHP_PROFILE}" ]]; then
      echo "sphp: sorry, this script assumes your profile is ${SPHP_PROFILE}."
      clean_exit 1
    else
      sed -i "/^path=(\/usr\/local\/opt\/php.*/s/^/#/" "${SPHP_PROFILE}"
      sed -i "/path=(\/usr\/local\/opt\/${REQUESTED_VERSION}/s/^#//" "${SPHP_PROFILE}"
    fi

    echo "Starting brew services..."
    brew services start "${REQUESTED_VERSION}" >/dev/null 2>&1

    echo "You're good to go!"
    exec /bin/zsh
    source "${SPHP_PROFILE}"
  else
    echo "sphp: ${REQUESTED_VERSION} is not available."
    echo ""
    echo "Try installing it by running: brew install ${REQUESTED_VERSION}"
    clean_exit 1
  fi
}

################################################################################
#
# RUN THE SCRIPT
# Nothing should be edited below this block.
#
################################################################################

# trap bad exits with your cleanup function
trap _trap EXIT INT TERM SIGINT SIGQUIT

# trap errors in subshells and functions
set -o errtrace

# bash will remember & return the highest exitcode in a chain of pipes
set -o pipefail

# parse arguments passed to script
parse_options "$@"

# main script run
main_run

# clean exit
clean_exit