diff --git a/.rubocop.yml b/.rubocop.yml
new file mode 100644
index 0000000..6995009
--- /dev/null
+++ b/.rubocop.yml
@@ -0,0 +1,4 @@
+inherit_from: .rubocop_todo.yml
+
+inherit_gem:
+  rubocop-lts: rubocop-lts1_8.yml
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
new file mode 100644
index 0000000..854fc4f
--- /dev/null
+++ b/.rubocop_todo.yml
@@ -0,0 +1,54 @@
+# This configuration was generated by
+# `rubocop --auto-gen-config`
+# on 2022-12-11 23:40:03 +0700 using RuboCop version 0.41.2.
+# The point is for the user to remove these configuration records
+# one by one as the offenses are removed from the code base.
+# Note that changes in the inspected code, or installation of new
+# versions of RuboCop, may require this file to be generated again.
+
+# Offense count: 1
+Lint/ParenthesesAsGroupedExpression:
+  Exclude:
+    - 'spec/os_spec.rb'
+
+# Offense count: 2
+Metrics/AbcSize:
+  Max: 31
+
+# Offense count: 1
+# Configuration parameters: CountComments.
+Metrics/ClassLength:
+  Max: 234
+
+# Offense count: 2
+Metrics/CyclomaticComplexity:
+  Max: 9
+
+# Offense count: 22
+# Configuration parameters: AllowHeredoc, AllowURI, URISchemes.
+# URISchemes: http, https
+Metrics/LineLength:
+  Max: 144
+
+# Offense count: 6
+# Configuration parameters: CountComments.
+Metrics/MethodLength:
+  Max: 26
+
+# Offense count: 3
+Metrics/PerceivedComplexity:
+  Max: 10
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle, SupportedStyles, UseHashRocketsWithSymbolValues, PreferHashRocketsForNonAlnumEndingSymbols.
+# SupportedStyles: ruby19, ruby19_no_mixed_keys, hash_rockets
+Style/HashSyntax:
+  Exclude:
+    - 'Rakefile'
+
+# Offense count: 2
+Style/IfInsideElse:
+  Exclude:
+    - 'lib/os.rb'
+    - 'spec/os_spec.rb'
diff --git a/Gemfile b/Gemfile
index c80ee36..fceb122 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,4 @@
-source "http://rubygems.org"
+# encoding: utf-8
+source 'http://rubygems.org'
 
 gemspec
diff --git a/Gemfile.lock b/Gemfile.lock
index 935aa3a..b83b180 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -6,6 +6,7 @@ PATH
 GEM
   remote: http://rubygems.org/
   specs:
+    ast (2.4.2)
     coderay (1.1.3)
     diff-lcs (1.5.0)
     ffi (1.15.5)
@@ -33,10 +34,15 @@ GEM
     notiffany (0.1.3)
       nenv (~> 0.1)
       shellany (~> 0.0)
+    parser (2.4.0.2)
+      ast (~> 2.3)
     power_assert (2.0.2)
+    powerpack (0.1.3)
     pry (0.14.1)
       coderay (~> 1.1)
       method_source (~> 1.0)
+    rainbow (2.2.2)
+      rake
     rake (10.5.0)
     rb-fsevent (0.11.2)
     rb-inotify (0.10.1)
@@ -54,10 +60,23 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.12.0)
     rspec-support (3.12.0)
+    rubocop (0.41.2)
+      parser (>= 2.3.1.1, < 3.0)
+      powerpack (~> 0.1)
+      rainbow (>= 1.99.1, < 3.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (~> 1.0, >= 1.0.1)
+    rubocop-lts (2.0.5)
+      rubocop-ruby1_9 (~> 1.0.5)
+    rubocop-ruby1_9 (1.0.5)
+      parser (= 2.4.0.2)
+      rubocop (= 0.41.2)
+    ruby-progressbar (1.11.0)
     shellany (0.0.1)
     test-unit (3.5.5)
       power_assert
     thor (1.2.1)
+    unicode-display_width (1.8.0)
 
 PLATFORMS
   x86_64-darwin-19
@@ -67,6 +86,7 @@ DEPENDENCIES
   os!
   rake (~> 10.5)
   rspec (~> 3.12)
+  rubocop-lts (~> 2.0)
   test-unit (~> 3.5)
 
 BUNDLED WITH
diff --git a/Guardfile b/Guardfile
index db914c1..9341543 100644
--- a/Guardfile
+++ b/Guardfile
@@ -1,7 +1,8 @@
+# encoding: utf-8
 # More info at https://github.com/guard/guard#readme
 
-guard :rspec, cmd: "bundle exec rspec" do
-  require "guard/rspec/dsl"
+guard :rspec, :cmd => 'bundle exec rspec' do
+  require 'guard/rspec/dsl'
   dsl = Guard::RSpec::Dsl.new(self)
 
   # Feel free to open issues for suggestions and improvements
diff --git a/Rakefile b/Rakefile
index b537520..241ada3 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,6 +1,32 @@
-require 'rubygems' if RUBY_VERSION < '1.9.0'
+# encoding: utf-8
+# frozen_string_literal: true
 
-require 'rspec/core/rake_task'
-RSpec::Core::RakeTask.new(:spec)
-task :default => :spec
+# !/usr/bin/env rake
 
+require 'bundler/gem_tasks'
+
+begin
+  require 'rspec/core/rake_task'
+  RSpec::Core::RakeTask.new(:spec)
+rescue LoadError
+  desc 'spec task stub'
+  task :spec do
+    warn 'rspec is disabled'
+  end
+end
+desc 'alias test task to spec'
+task :test => :spec
+
+begin
+  require 'rubocop/rake_task'
+  RuboCop::RakeTask.new do |task|
+    task.options = ['-D'] # Display the name of the failing cops
+  end
+rescue LoadError
+  desc 'rubocop task stub'
+  task :rubocop do
+    warn 'RuboCop is disabled'
+  end
+end
+
+task default: %i[test rubocop]
diff --git a/lib/os.rb b/lib/os.rb
index c65764d..16406cc 100644
--- a/lib/os.rb
+++ b/lib/os.rb
@@ -1,317 +1,303 @@
-require 'rbconfig'
-require 'yaml'
-
-# a set of friendly files for determining your Ruby runtime
-# treats cygwin as linux
-# also treats IronRuby on mono as...linux
-class OS
-  attr_reader :config
-
-  def self.config
-    @config ||= RbConfig::CONFIG
-  end
-
-  # true if on windows [and/or jruby]
-  # false if on linux or cygwin on windows
-
-  def self.windows?
-    @windows ||= begin
-      if RUBY_PLATFORM =~ /cygwin/ # i386-cygwin
-        false
-      elsif ENV['OS'] == 'Windows_NT'
-        true
-      else
-        false
-      end
-    end
-
-  end
-
-  # true for linux, os x, cygwin
-  def self.posix?
-    @posix ||=
-    begin
-      if OS.windows?
-        begin
-          begin
-            # what if we're on interix...
-            # untested, of course
-            Process.wait fork{}
-            true
-          rescue NotImplementedError, NoMethodError
-            false
-          end
-        end
-      else
-        # assume non windows is posix
-        true
-      end
-    end
-
-  end
-
-  # true for linux, false for windows, os x, cygwin
-  def self.linux?
-    if (host_os =~ /linux/)
-      true
-    else
-      false
-    end
-  end
-
-  def self.freebsd?
-    if (host_os =~ /freebsd/)
-      true
-    else
-      false
-    end
-  end
-
-  def self.iron_ruby?
-   @iron_ruby ||= begin
-     if defined?(RUBY_ENGINE) && (RUBY_ENGINE == 'ironruby')
-       true
-     else
-       false
-     end
-   end
-  end
-
-  def self.bits
-    @bits ||= begin
-      if host_cpu =~ /_64$/ || RUBY_PLATFORM =~ /x86_64/
-        64
-      elsif RUBY_PLATFORM == 'java' && ENV_JAVA['sun.arch.data.model'] # "32" or "64":http://www.ruby-forum.com/topic/202173#880613
-        ENV_JAVA['sun.arch.data.model'].to_i
-      elsif host_cpu == 'i386'
-        32
-      elsif host_os =~ /32$/ # mingw32, mswin32
-        32
-      else # cygwin only...I think
-        if 1.size == 8
-          64
-        else
-          32
-        end
-      end
-    end
-  end
-
-
-  def self.java?
-    @java ||= begin
-      if RUBY_PLATFORM =~ /java/
-        true
-      else
-        false
-      end
-    end
-  end
-
-  def self.ruby_bin
-    @ruby_exe ||= begin
-      File::join(config['bindir'], config['ruby_install_name']) + config['EXEEXT']
-    end
-  end
-
-  def self.mac?
-    @mac = begin
-      if host_os =~ /darwin/
-        true
-      else
-        false
-      end
-    end
-  end
-
-  def self.osx?
-    mac?
-  end
-
-  def self.x?
-    mac?
-  end
-
-
-  # amount of memory the current process "is using", in RAM
-  # (doesn't include any swap memory that it may be using, just that in actual RAM)
-  # raises 'unknown' on jruby currently
-  def self.rss_bytes
-    # attempt to do this in a jruby friendly way
-    if OS::Underlying.windows?
-      # MRI, Java, IronRuby, Cygwin
-      if OS.java?
-        # no win32ole on 1.5.x, so leave here for compatibility...maybe for awhile :P
-        require 'java'
-        mem_bean = java.lang.management.ManagementFactory.getMemoryMXBean
-        mem_bean.heap_memory_usage.used + mem_bean.non_heap_memory_usage.used
-      else
-        wmi = nil
-        begin
-          require 'win32ole'
-          wmi = WIN32OLE.connect("winmgmts://")
-        rescue LoadError, NoMethodError => e # NoMethod for IronRuby currently [sigh]
-          raise 'rss unknown for this platform ' + e.to_s
-        end
-        processes = wmi.ExecQuery("select * from win32_process where ProcessId = #{Process.pid}")
-        memory_used = nil
-        # only allow for one process...
-        for process in processes
-          raise "multiple processes same pid?" if memory_used
-          memory_used = process.WorkingSetSize.to_i
-        end
-        memory_used
-      end
-    elsif OS.posix? # linux [though I've heard it works in OS X]
-      `ps -o rss= -p #{Process.pid}`.to_i * 1024 # in kiloBytes
-    else
-      raise 'unknown rss for this platform'
-    end
-  end
-
-  class Underlying
-
-    def self.bsd?
-      OS.osx?
-    end
-
-    def self.windows?
-      ENV['OS'] == 'Windows_NT'
-    end
-
-    def self.linux?
-      OS.host_os =~ /linux/ ? true : false
-    end
-
-    def self.docker?
-      system('grep -q docker /proc/self/cgroup') if OS.linux?
-    end
-
-  end
-
-  def self.cygwin?
-    @cygwin = begin
-      if RUBY_PLATFORM =~ /-cygwin/
-        true
-      else
-        false
-      end
-    end
-  end
-
-  def self.dev_null # File::NULL in 1.9.3+
-    @dev_null ||= begin
-      if OS.windows?
-        "NUL"
-      else
-        "/dev/null"
-      end
-    end
-  end
-
-  # provides easy way to see the relevant config entries
-  def self.report
-    relevant_keys = [
-      'arch',
-      'host',
-      'host_cpu',
-      'host_os',
-      'host_vendor',
-      'target',
-      'target_cpu',
-      'target_os',
-      'target_vendor',
-    ]
-    RbConfig::CONFIG.reject {|key, val| !relevant_keys.include? key }.merge({'RUBY_PLATFORM' => RUBY_PLATFORM}).to_yaml
-  end
-
-  def self.cpu_count
-    @cpu_count ||=
-    case RUBY_PLATFORM
-    when /darwin9/
-      `hwprefs cpu_count`.to_i
-    when /darwin10/
-      (hwprefs_available? ? `hwprefs thread_count` : `sysctl -n hw.ncpu`).to_i
-    when /linux/
-      `cat /proc/cpuinfo | grep processor | wc -l`.to_i
-    when /freebsd/
-      `sysctl -n hw.ncpu`.to_i
-    else
-      if RbConfig::CONFIG['host_os'] =~ /darwin/
-         (hwprefs_available? ? `hwprefs thread_count` : `sysctl -n hw.ncpu`).to_i
-      elsif self.windows?
-        # ENV counts hyper threaded...not good.
-      	      # out = ENV['NUMBER_OF_PROCESSORS'].to_i
-        require 'win32ole'
-        wmi = WIN32OLE.connect("winmgmts://")
-        cpu = wmi.ExecQuery("select NumberOfCores from Win32_Processor") # don't count hyper-threaded in this
-        cpu.to_enum.first.NumberOfCores
-      else
-        raise 'unknown platform processor_count'
-      end
-    end
-  end
-
-  def self.open_file_command
-    if OS.cygwin?
-      "cygstart"
-    elsif OS.doze?
-      "start"
-    elsif OS.mac?
-      "open"
-    else
-      "xdg-open"
-    end
-  end
-
-  def self.app_config_path(name)
-    if OS.doze?
-      if ENV['LOCALAPPDATA']
-        return File.join(ENV['LOCALAPPDATA'], name)
-      end
-
-      File.join ENV['USERPROFILE'], 'Local Settings', 'Application Data', name
-    elsif OS.mac?
-      File.join ENV['HOME'], 'Library', 'Application Support', name
-    else
-      if ENV['XDG_CONFIG_HOME']
-        return File.join(ENV['XDG_CONFIG_HOME'], name)
-      end
-
-      File.join ENV['HOME'], '.config', name
-    end
-  end
-
-  def self.parse_os_release
-    if OS.linux? && File.exist?('/etc/os-release')
-      output = {}
-
-      File.read('/etc/os-release').each_line do |line|
-        parsed_line = line.chomp.tr('"', '').split('=')
-        next if parsed_line.empty?
-        output[parsed_line[0].to_sym] = parsed_line[1]
-      end
-      output
-    else
-      raise "File /etc/os-release doesn't exists or not Linux"
-    end
-  end
-
-  class << self
-    alias :doze? :windows? # a joke name but I use it and like it :P
-    alias :jruby? :java?
-
-    # delegators for relevant config values
-    %w(host host_cpu host_os).each do |method_name|
-      define_method(method_name) { config[method_name] }
-    end
-
-  end
-
-  private
-
-  def self.hwprefs_available?
-    `which hwprefs` != ''
-  end
-
-end
+# encoding: utf-8
+require 'rbconfig'
+require 'yaml'
+
+# a set of friendly files for determining your Ruby runtime
+# treats cygwin as linux
+# also treats IronRuby on mono as...linux
+class OS
+  attr_reader :config
+
+  def self.config
+    @config ||= RbConfig::CONFIG
+  end
+
+  # true if on windows [and/or jruby]
+  # false if on linux or cygwin on windows
+
+  def self.windows?
+    @windows ||= begin
+      if RUBY_PLATFORM =~ /cygwin/ # i386-cygwin
+        false
+      elsif ENV['OS'] == 'Windows_NT'
+        true
+      else
+        false
+      end
+    end
+  end
+
+  # true for linux, os x, cygwin
+  def self.posix?
+    @posix ||=
+      begin
+        if OS.windows?
+          begin
+            begin
+              # what if we're on interix...
+              # untested, of course
+              Process.wait fork {}
+              true
+            rescue NotImplementedError, NoMethodError
+              false
+            end
+          end
+        else
+          # assume non windows is posix
+          true
+        end
+      end
+  end
+
+  # true for linux, false for windows, os x, cygwin
+  def self.linux?
+    if host_os =~ /linux/
+      true
+    else
+      false
+    end
+  end
+
+  def self.freebsd?
+    if host_os =~ /freebsd/
+      true
+    else
+      false
+    end
+  end
+
+  def self.iron_ruby?
+    @iron_ruby ||= begin
+      if defined?(RUBY_ENGINE) && (RUBY_ENGINE == 'ironruby')
+        true
+      else
+        false
+      end
+    end
+  end
+
+  def self.bits
+    @bits ||= begin
+      if host_cpu =~ /_64$/ || RUBY_PLATFORM =~ /x86_64/
+        64
+      elsif RUBY_PLATFORM == 'java' && ENV_JAVA['sun.arch.data.model'] # "32" or "64":http://www.ruby-forum.com/topic/202173#880613
+        ENV_JAVA['sun.arch.data.model'].to_i
+      elsif host_cpu == 'i386'
+        32
+      elsif host_os =~ /32$/ # mingw32, mswin32
+        32
+      else # cygwin only...I think
+        if 1.size == 8
+          64
+        else
+          32
+        end
+      end
+    end
+  end
+
+  def self.java?
+    @java ||= begin
+      if RUBY_PLATFORM =~ /java/
+        true
+      else
+        false
+      end
+    end
+  end
+
+  def self.ruby_bin
+    @ruby_exe ||= begin
+      File.join(config['bindir'], config['ruby_install_name']) + config['EXEEXT']
+    end
+  end
+
+  def self.mac?
+    @mac = begin
+      if host_os =~ /darwin/
+        true
+      else
+        false
+      end
+    end
+  end
+
+  def self.osx?
+    mac?
+  end
+
+  def self.x?
+    mac?
+  end
+
+  # amount of memory the current process "is using", in RAM
+  # (doesn't include any swap memory that it may be using, just that in actual RAM)
+  # raises 'unknown' on jruby currently
+  def self.rss_bytes
+    # attempt to do this in a jruby friendly way
+    if OS::Underlying.windows?
+      # MRI, Java, IronRuby, Cygwin
+      if OS.java?
+        # no win32ole on 1.5.x, so leave here for compatibility...maybe for awhile :P
+        require 'java'
+        mem_bean = java.lang.management.ManagementFactory.getMemoryMXBean
+        mem_bean.heap_memory_usage.used + mem_bean.non_heap_memory_usage.used
+      else
+        wmi = nil
+        begin
+          require 'win32ole'
+          wmi = WIN32OLE.connect('winmgmts://')
+        rescue LoadError, NoMethodError => e # NoMethod for IronRuby currently [sigh]
+          raise 'rss unknown for this platform ' + e.to_s
+        end
+        processes = wmi.ExecQuery("select * from win32_process where ProcessId = #{Process.pid}")
+        memory_used = nil
+        # only allow for one process...
+        processes.each do |process|
+          raise 'multiple processes same pid?' if memory_used
+          memory_used = process.WorkingSetSize.to_i
+        end
+        memory_used
+      end
+    elsif OS.posix? # linux [though I've heard it works in OS X]
+      `ps -o rss= -p #{Process.pid}`.to_i * 1024 # in kiloBytes
+    else
+      raise 'unknown rss for this platform'
+    end
+  end
+
+  class Underlying
+    def self.bsd?
+      OS.osx?
+    end
+
+    def self.windows?
+      ENV['OS'] == 'Windows_NT'
+    end
+
+    def self.linux?
+      OS.host_os =~ /linux/ ? true : false
+    end
+
+    def self.docker?
+      system('grep -q docker /proc/self/cgroup') if OS.linux?
+    end
+  end
+
+  def self.cygwin?
+    @cygwin = begin
+      if RUBY_PLATFORM =~ /-cygwin/
+        true
+      else
+        false
+      end
+    end
+  end
+
+  def self.dev_null # File::NULL in 1.9.3+
+    @dev_null ||= begin
+      if OS.windows?
+        'NUL'
+      else
+        '/dev/null'
+      end
+    end
+  end
+
+  # provides easy way to see the relevant config entries
+  def self.report
+    relevant_keys = [
+      'arch',
+      'host',
+      'host_cpu',
+      'host_os',
+      'host_vendor',
+      'target',
+      'target_cpu',
+      'target_os',
+      'target_vendor'
+    ]
+    RbConfig::CONFIG.reject { |key, _val| !relevant_keys.include? key }.merge('RUBY_PLATFORM' => RUBY_PLATFORM).to_yaml
+  end
+
+  def self.cpu_count
+    @cpu_count ||=
+      case RUBY_PLATFORM
+      when /darwin9/
+        `hwprefs cpu_count`.to_i
+      when /darwin10/
+        (hwprefs_available? ? `hwprefs thread_count` : `sysctl -n hw.ncpu`).to_i
+      when /linux/
+        `cat /proc/cpuinfo | grep processor | wc -l`.to_i
+      when /freebsd/
+        `sysctl -n hw.ncpu`.to_i
+      else
+        if RbConfig::CONFIG['host_os'] =~ /darwin/
+          (hwprefs_available? ? `hwprefs thread_count` : `sysctl -n hw.ncpu`).to_i
+        elsif windows?
+          # ENV counts hyper threaded...not good.
+          # out = ENV['NUMBER_OF_PROCESSORS'].to_i
+          require 'win32ole'
+          wmi = WIN32OLE.connect('winmgmts://')
+          cpu = wmi.ExecQuery('select NumberOfCores from Win32_Processor') # don't count hyper-threaded in this
+          cpu.to_enum.first.NumberOfCores
+        else
+          raise 'unknown platform processor_count'
+        end
+      end
+  end
+
+  def self.open_file_command
+    if OS.cygwin?
+      'cygstart'
+    elsif OS.doze?
+      'start'
+    elsif OS.mac?
+      'open'
+    else
+      'xdg-open'
+    end
+  end
+
+  def self.app_config_path(name)
+    if OS.doze?
+      return File.join(ENV['LOCALAPPDATA'], name) if ENV['LOCALAPPDATA']
+
+      File.join ENV['USERPROFILE'], 'Local Settings', 'Application Data', name
+    elsif OS.mac?
+      File.join ENV['HOME'], 'Library', 'Application Support', name
+    else
+      return File.join(ENV['XDG_CONFIG_HOME'], name) if ENV['XDG_CONFIG_HOME']
+
+      File.join ENV['HOME'], '.config', name
+    end
+  end
+
+  def self.parse_os_release
+    raise "File /etc/os-release doesn't exists or not Linux" unless OS.linux? && File.exist?('/etc/os-release')
+
+    output = {}
+    File.read('/etc/os-release').each_line do |line|
+      parsed_line = line.chomp.tr('"', '').split('=')
+      next if parsed_line.empty?
+      output[parsed_line[0].to_sym] = parsed_line[1]
+    end
+    output
+  end
+
+  class << self
+    alias doze? windows? # a joke name but I use it and like it :P
+    alias jruby? java?
+
+    # delegators for relevant config values
+    ['host', 'host_cpu', 'host_os'].each do |method_name|
+      define_method(method_name) { config[method_name] }
+    end
+
+    private
+
+    def hwprefs_available?
+      `which hwprefs` != ''
+    end
+  end
+end
diff --git a/os.gemspec b/os.gemspec
index 6c2cdd6..b7ebcd2 100644
--- a/os.gemspec
+++ b/os.gemspec
@@ -1,3 +1,4 @@
+# encoding: utf-8
 # Generated by jeweler
 # DO NOT EDIT THIS FILE DIRECTLY
 # Instead, edit Jeweler::Tasks in Rakefile, and run 'rake gemspec'
@@ -5,31 +6,32 @@
 # stub: os 1.1.4 ruby lib
 
 Gem::Specification.new do |s|
-  s.name = "os".freeze
-  s.version = "1.1.4"
+  s.name = 'os'.freeze
+  s.version = '1.1.4'
 
-  s.required_rubygems_version = Gem::Requirement.new(">= 0".freeze) if s.respond_to? :required_rubygems_version=
-  s.require_paths = ["lib".freeze]
-  s.authors = ["rdp".freeze, "David McCullars".freeze]
-  s.date = "2021-11-07"
-  s.description = "The OS gem allows for some useful and easy functions, like OS.windows? (=> true or false) OS.bits ( => 32 or 64) etc\"".freeze
-  s.email = "rogerpack2005@gmail.com".freeze
+  s.required_rubygems_version = Gem::Requirement.new('>= 0'.freeze) if s.respond_to? :required_rubygems_version=
+  s.require_paths = ['lib'.freeze]
+  s.authors = ['rdp'.freeze, 'David McCullars'.freeze]
+  s.date = '2021-11-07'
+  s.description = 'The OS gem allows for some useful and easy functions, like OS.windows? (=> true or false) OS.bits ( => 32 or 64) etc"'.freeze
+  s.email = 'rogerpack2005@gmail.com'.freeze
   s.files = [
-    "ChangeLog",
-    "Gemfile",
-    "LICENSE",
-    "README.md",
-    "Rakefile",
-    "lib/os.rb",
-    "os.gemspec",
+    'ChangeLog',
+    'Gemfile',
+    'LICENSE',
+    'README.md',
+    'Rakefile',
+    'lib/os.rb',
+    'os.gemspec'
   ]
-  s.homepage = "https://github.com/rdp/os".freeze
-  s.licenses = ["MIT".freeze]
-  s.rubygems_version = "2.7.6".freeze
+  s.homepage = 'https://github.com/rdp/os'.freeze
+  s.licenses = ['MIT'.freeze]
+  s.rubygems_version = '2.7.6'.freeze
   s.summary = "Simple and easy way to know if you're on windows or not (reliably), as well as how many bits the OS is, etc.".freeze
 
-  s.add_development_dependency(%q<rake>.freeze, ["~> 10.5"])
-  s.add_development_dependency(%q<test-unit>.freeze, ["~> 3.5"])
-  s.add_development_dependency(%q<rspec>.freeze, ["~> 3.12"])
-  s.add_development_dependency(%q<guard-rspec>.freeze, ["~> 4.7"])
+  s.add_development_dependency('guard-rspec'.freeze, ['~> 4.7'])
+  s.add_development_dependency('rake'.freeze, ['~> 10.5'])
+  s.add_development_dependency('rspec'.freeze, ['~> 3.12'])
+  s.add_development_dependency('rubocop-lts'.freeze, ['~> 2.0']) # For Ruby 1.8.7 compat
+  s.add_development_dependency('test-unit'.freeze, ['~> 3.5'])
 end
diff --git a/spec/config/rspec/rspec_core.rb b/spec/config/rspec/rspec_core.rb
index 10f8c98..3660b26 100644
--- a/spec/config/rspec/rspec_core.rb
+++ b/spec/config/rspec/rspec_core.rb
@@ -1,3 +1,4 @@
+# encoding: utf-8
 # frozen_string_literal: true
 
 RSpec.configure do |config|
diff --git a/spec/linux_spec.rb b/spec/linux_spec.rb
index 93ef7ab..c34e698 100644
--- a/spec/linux_spec.rb
+++ b/spec/linux_spec.rb
@@ -1,3 +1,4 @@
+# encoding: utf-8
 describe 'For Linux, (Ubuntu, Ubuntu 10.04 LTS) ' do
   before(:each) do
     allow(ENV).to receive(:[]).with('OS')
@@ -18,7 +19,6 @@
     it { is_expected.not_to be_mac }
     it { is_expected.not_to be_osx }
     it { is_expected.not_to be_windows }
-
   end
 
   describe OS::Underlying do
@@ -30,4 +30,3 @@
     it { is_expected.not_to be_windows }
   end
 end
-
diff --git a/spec/os_spec.rb b/spec/os_spec.rb
index 8ed97b0..1f47269 100644
--- a/spec/os_spec.rb
+++ b/spec/os_spec.rb
@@ -1,27 +1,27 @@
-describe "OS" do
-
-  it "identifies whether windows? or posix?" do
+# encoding: utf-8
+describe 'OS' do
+  it 'identifies whether windows? or posix?' do
     if ENV['OS'] == 'Windows_NT'
-      unless RUBY_PLATFORM =~ /cygwin/
-        assert OS.windows? == true
-        assert OS.doze? == true
-        assert OS.posix? == false # can fail in error at times...I guess because some other spec has reset ENV on us...
-      else
+      if RUBY_PLATFORM =~ /cygwin/
         assert OS::Underlying.windows?
         assert OS.windows? == false
         assert OS.posix? == true
+      else
+        assert OS.windows? == true
+        assert OS.doze? == true
+        assert OS.posix? == false # can fail in error at times...I guess because some other spec has reset ENV on us...
       end
       assert OS::Underlying.windows?
-    elsif [/linux/, /darwin/].any? {|posix_pattern| (RbConfig::CONFIG["host_os"] =~ posix_pattern) || RUBY_PLATFORM =~ posix_pattern }
+    elsif [/linux/, /darwin/].any? { |posix_pattern| (RbConfig::CONFIG['host_os'] =~ posix_pattern) || RUBY_PLATFORM =~ posix_pattern }
       assert OS.windows? == false
       assert OS.posix? == true
       assert !OS::Underlying.windows?
     else
-      skip "create test"
+      skip 'create test'
     end
   end
 
-  it "has a bits method" do
+  it 'has a bits method' do
     if RUBY_PLATFORM =~ /mingw32/
       assert OS.bits == 32
     elsif RUBY_PLATFORM =~ /64/ # linux...
@@ -35,12 +35,11 @@
     elsif RUBY_PLATFORM =~ /i386/
       assert OS.bits == 32
     else
-      skip "os bits not tested!" + RUBY_PLATFORM + ' ' +  RbConfig::CONFIG['host_os']
+      skip 'os bits not tested!' + RUBY_PLATFORM + ' ' + RbConfig::CONFIG['host_os']
     end
-
   end
 
-  it "should have an iron_ruby method" do
+  it 'should have an iron_ruby method' do
     if defined?(RUBY_ENGINE) && RUBY_ENGINE == 'ironruby'
       assert OS.iron_ruby? == true
     else
@@ -56,7 +55,7 @@
     end
   end
 
-  it "should have a ruby_bin method" do
+  it 'should have a ruby_bin method' do
     if OS.windows?
       assert OS.ruby_bin.include?('.exe')
       if OS.iron_ruby?
@@ -71,10 +70,9 @@
     if OS.java?
       assert OS.ruby_bin.include?('jruby') # I think
     end
-
   end
 
-  it "should have a cygwin? method" do
+  it 'should have a cygwin? method' do
     if RUBY_PLATFORM =~ /cygwin/
       assert OS.cygwin? == true
     else
@@ -82,7 +80,7 @@
     end
   end
 
-  it "should have a functional mac? method" do
+  it 'should have a functional mac? method' do
     if RUBY_PLATFORM =~ /darwin/
       assert OS.mac? == true
     else
@@ -94,21 +92,21 @@
     end
   end
 
-  it "should have a way to get rss_bytes on each platform" do
+  it 'should have a way to get rss_bytes on each platform' do
     bytes = OS.rss_bytes
     assert bytes > 0 # should always be true
     assert bytes.is_a?(Numeric) # don't want strings from any platform...
   end
 
-  it "should tell you what the right /dev/null is" do
+  it 'should tell you what the right /dev/null is' do
     if OS.windows?
-      expect(OS.dev_null).to eq("NUL")
+      expect(OS.dev_null).to eq('NUL')
     else
-      expect(OS.dev_null).to eq("/dev/null")
+      expect(OS.dev_null).to eq('/dev/null')
     end
   end
 
-  it "should have a jruby method" do
+  it 'should have a jruby method' do
     if defined?(RUBY_DESCRIPTION) && RUBY_DESCRIPTION =~ /^(jruby|java)/
       assert OS.jruby?
     else
@@ -116,14 +114,14 @@
     end
   end
 
-  it "has working cpu count method" do
+  it 'has working cpu count method' do
     cpu_count = OS.cpu_count
     assert cpu_count >= 1
     # CPU count is usually either a power of 2 or an even number.
-    assert ((cpu_count & (cpu_count - 1)) == 0) || ((cpu_count % 2) == 0)
+    assert ((cpu_count & (cpu_count - 1)) == 0) || cpu_count.even?
   end
 
-  it "has working cpu count method with no env. variable" do
+  it 'has working cpu count method with no env. variable' do
     OS.instance_variable_set(:@cpu_count, nil) # reset it
     if OS.windows?
       ENV.delete('NUMBER_OF_PROCESSORS')
@@ -131,17 +129,17 @@
     end
   end
 
-  it "should have a start/open command helper" do
+  it 'should have a start/open command helper' do
     if OS.doze?
-      assert OS.open_file_command == "start"
+      assert OS.open_file_command == 'start'
     elsif OS.mac?
-      assert OS.open_file_command == "open"
+      assert OS.open_file_command == 'open'
     else
-      assert OS.open_file_command == "xdg-open"
+      assert OS.open_file_command == 'xdg-open'
     end
   end
 
-  it "should provide a path to directory for application config" do
+  it 'should provide a path to directory for application config' do
     allow(ENV).to receive(:[])
     home = '/home/user'
 
@@ -159,19 +157,17 @@
     end
   end
 
-  it "should have a freebsd? method" do
+  it 'should have a freebsd? method' do
     if OS.host_os =~ /freebsd/
       assert OS.freebsd? == true
     else
       assert OS.freebsd? == false
     end
   end
-
 end
 
-describe OS, "provides access to to underlying config values" do
-
-  describe "#config, supplys the CONFIG hash" do
+describe OS, 'provides access to to underlying config values' do
+  describe '#config, supplys the CONFIG hash' do
     subject { OS.config }
 
     specify { expect(subject).to be_a(Hash) }
@@ -185,8 +181,8 @@
     end
   end
 
-  describe "by providing a delegate method for relevant keys in RbConfig::CONFIG" do
-    %w(host host_cpu host_os).sort.each do |config_key|
+  describe 'by providing a delegate method for relevant keys in RbConfig::CONFIG' do
+    ['host', 'host_cpu', 'host_os'].sort.each do |config_key|
       it "should delegate '#{config_key}'" do
         expected = "TEST #{config_key}"
         expect(RbConfig::CONFIG).to receive(:[]).with(config_key).and_return(expected)
diff --git a/spec/osx_spec.rb b/spec/osx_spec.rb
index 04b7f4d..626f532 100644
--- a/spec/osx_spec.rb
+++ b/spec/osx_spec.rb
@@ -1,9 +1,10 @@
+# encoding: utf-8
 describe 'For OSX (Snow Leopard, 10.6),' do
   before(:each) do
     allow(ENV).to receive(:[]).with('OS').and_return(nil)
     # Issues stubbing RUBY_PLATFORM, using RbConfig instead.
     # Kernel.stub!(:RUBY_PLATFORM => "x86_64-darwin10.6")
-    allow(RbConfig::CONFIG).to receive(:[]).with('host_os').and_return("darwin10.6.0")
+    allow(RbConfig::CONFIG).to receive(:[]).with('host_os').and_return('darwin10.6.0')
     allow(RbConfig::CONFIG).to receive(:[]).with('host_cpu').and_return('i386')
   end
 
@@ -16,7 +17,6 @@
     it { is_expected.to be_posix }
 
     it { is_expected.not_to be_windows }
-
   end
 
   describe OS::Underlying do
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 36cf044..b9fe043 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,3 +1,4 @@
+# encoding: utf-8
 # Third Party Libraries
 require 'rspec'