archlinux-java fixed shellcheck error

archlinux-java

#! /bin/bash

# Arch Linux helper script to set/unset/check/fix the enabled Java environment
# This program may be freely redistributed under the terms of the GNU General Public License
#
# Author: Guillaume ALAUX <guillaume@archlinux.org>
#         Yamada Hayao <hayao@fascode.net>

JVM_DIR=/usr/lib/jvm
DEFAULT_NAME=default
DEFAULT_PATH=${JVM_DIR}/${DEFAULT_NAME}
DEFAULT_NAME_JRE="default-runtime"
DEFAULT_PATH_JRE=${JVM_DIR}/${DEFAULT_NAME_JRE}


# Utility functions

check_root() {
  #if [ $(id -u) -ne 0 ]; then
  if (( UID != 0 )); then
    echo 'This script must be run as root'
    exit 1
  fi
}

# $1: parameter count given to this script for this option
# $2: expected parameter count for this option
check_param_count() {
  if [[ "${1}" -ne "${2}" ]]; then
    echo 'Wrong parameter count'
    exit 2
  fi
}

# Second level functions

get_default_java() {
  path=$(readlink -e ${DEFAULT_PATH})
  if [[ "${path}" != "/dev/null" ]]; then
    echo "${path/${JVM_DIR}\/}"
  else
    echo ""
  fi
}

get_installed_javas() {
  if [[ -d "${JVM_DIR}" ]]; then
    for dir in $(find ${JVM_DIR} -mindepth 1 -maxdepth 1 -type d | sort); do
      if [ -x "${dir}/bin/java" ]; then
        javas+=("${dir/${JVM_DIR}\/}")
      else
        if [ -x "${dir}/jre/bin/java" ]; then
        javas+=("${dir/${JVM_DIR}\/}/jre")
        fi
      fi
    done
  fi
  echo "${javas[*]}"
}

# $1: Java environment name to test
is_java_valid() {
  [[ "${1}" != "${DEFAULT_NAME}" ]] && [[ -x "${JVM_DIR}/${1}/bin/java" ]]
}

# $1: Java environment name to set as default
set_default_link_to() {
  new_default="${1}"
  unlink "${DEFAULT_PATH}" 2>/dev/null
  ln -sf "${new_default}" "${DEFAULT_PATH}"

  unlink "${DEFAULT_PATH_JRE}" 2>/dev/null
  if [[ -d "${new_default}/jre" ]]; then
    ln -sf "${new_default}/jre" "${DEFAULT_PATH_JRE}"
  else
    ln -sf "${new_default}" "${DEFAULT_PATH_JRE}"
  fi
}

unset_default_link() {
  unlink ${DEFAULT_PATH} 2>/dev/null
  unlink ${DEFAULT_PATH_JRE} 2>/dev/null
}

# First level functions

do_status() {
  #installed_java=($(get_installed_javas))
  IFS=" " read -r -a installed_java < <(get_installed_javas)
  if [ ${#installed_java[@]} -eq 0 ]; then
    echo 'No compatible Java environment installed'
  else
    default_java=$(get_default_java)
    echo 'Available Java environments:'
    for java in "${installed_java[@]}"; do
      # We discoverd this Java env but its JRE is actually set as default
      if [ "${java}/jre" = "${default_java}" ]; then
        echo -e "  ${java} (${java}/jre default)"
      elif [ "${java}" = "${default_java}" ]; then
        echo -e "  ${java} (default)"
      else
        echo "  ${java}"
      fi
    done
    if [ -z "${default_java}" ]; then
      echo "No Java environment set as default"
    fi
  fi
}

do_get() {
  get_default_java
}

# $1: Java environment name to set as default
do_set() {
  if ! is_java_valid "${1}"; then
    echo "'${JVM_DIR}/$1' is not a valid Java environment path"
    exit 1
  fi
  default=$(get_default_java)
  if [[ "$1" != "${default}" ]] || ! is_java_valid "${default}"; then
    unset_default_link
    set_default_link_to "${1}"
  fi

  #parent_dir=$(dirname $1)
  #if is_java_valid ${parent_dir}; then
  #  echo "Warning: '${parent_dir}' looks like a valid JDK whereas '$1' is set as default"
  #  echo "Fix this with 'archlinux-java set ${parent_dir}'"
  #fi
}

# $1: Java environment name to unset
do_unset() {
  unset_default_link
}

do_fix() {
  default=$(get_default_java)
  if is_java_valid "${default}"; then
    # If its parent is also a valid Java environment
    if is_java_valid "$(dirname "${default}")"; then
      unset_default_link
      set_default_link_to "$(dirname "${default}")"
    fi
  else
    prev=$(readlink ${DEFAULT_PATH})
    unset_default_link
    potential_fixes=("${prev/\/jre}" "${prev}/jre")
    openjdk8=('java-8-openjdk' 'java-8-openjdk/jre')
    # List of environments to check by order of preference:
    # - first potential fixes of user choices,
    # - then OpenJDK8 as it is considered a default in Arch Linux
    # - finally, any installed environment
    IFS=" " read -r -a to_check < <(get_installed_javas)
    to_check=("${potential_fixes[@]}" "${openjdk8[@]}" "${to_check[@]}")
    for java in "${to_check[@]}"; do
      if ! is_java_valid "$(get_default_java)" && is_java_valid "${java}"; then
        set_default_link_to "${java}"
      fi
    done
  fi
  if ! is_java_valid "$(get_default_java)"; then
    echo 'No valid Java environment found'
  fi
}

usage() {
  echo "$(basename "${0}") <COMMAND>"
  echo -e "\nCOMMAND:"
  echo -e '\tstatus\t\tList installed Java environments and enabled one'
  echo -e '\tget\t\tReturn the short name of the Java environment set as default'
  echo -e '\tset <JAVA_ENV>\tForce <JAVA_ENV> as default'
  echo -e '\tunset\t\tUnset current default Java environment'
  echo -e '\tfix\t\tFix an invalid/broken default Java environment configuration'
}

## Main
case "${1}" in
  'status') do_status;;
  'get')    do_get;;
  'set')    check_root; check_param_count "${#}" 2; do_set "${2}";;
  'unset')  check_root; do_unset;;
  'fix')    check_root; do_fix;;
  'help' | '--help' | '-h' | '') usage;;
  *)           echo "$(basename "${0}"): unknown option '${*}'"; exit 1;;
esac