diff --git a/clean_files.txt b/clean_files.txt
index 4e515856..e1fed981 100644
--- a/clean_files.txt
+++ b/clean_files.txt
@@ -104,6 +104,8 @@ plugins/available/jump.plugin.bash
 plugins/available/less-pretty-cat.plugin.bash
 plugins/available/node.plugin.bash
 plugins/available/nodenv.plugin.bash
+plugins/available/osx-timemachine.plugin.bash
+plugins/available/osx.plugin.bash
 plugins/available/percol.plugin.bash
 plugins/available/plenv.plugin.bash
 plugins/available/pyenv.plugin.bash
diff --git a/plugins/available/osx-timemachine.plugin.bash b/plugins/available/osx-timemachine.plugin.bash
index 3d7ff00c..e30d37bd 100644
--- a/plugins/available/osx-timemachine.plugin.bash
+++ b/plugins/available/osx-timemachine.plugin.bash
@@ -1,84 +1,95 @@
-cite about-plugin
+# shellcheck shell=bash
 about-plugin 'OS X Time Machine functions'
 
-function time-machine-destination() {
-  group "osx-timemachine"
-  about "Shows the OS X Time Machine destination/mount point"
+if [[ "${OSTYPE}" != 'darwin'* ]]; then
+	_log_warning "This plugin only works with Mac OS X"
+	return 1
+fi
 
-  echo $(tmutil destinationinfo | grep "Mount Point" | sed -e 's/Mount Point   : \(.*\)/\1/g')
+function time-machine-destination() {
+	group "osx-timemachine"
+	about "Shows the OS X Time Machine destination/mount point"
+
+	tmutil destinationinfo | grep "Mount Point" | sed -e 's/Mount Point   : \(.*\)/\1/g'
 }
 
 function time-machine-list-machines() {
-  group "osx-timemachine"
-  about "Lists the OS X Time Machine machines on the backup volume"
+	group "osx-timemachine"
+	about "Lists the OS X Time Machine machines on the backup volume"
 
-  local tmdest="$(time-machine-destination)/Backups.backupdb"
+	local tmdest
+	tmdest="$(time-machine-destination)/Backups.backupdb"
 
-  find "$tmdest" -maxdepth 1 -mindepth 1 -type d | grep -v "/\." | while read line ; do
-    echo "${line##*/}"
-  done
+	find "$tmdest" -maxdepth 1 -mindepth 1 -type d | grep -v "/\." | while read -r line; do
+		echo "${line##*/}"
+	done
 }
 
 function time-machine-list-all-backups() {
-  group "osx-timemachine"
-  about "Shows all of the backups for the specified machine"
-  param "1: Machine name (optional)"
-  example "time-machine-list-all-backups my-laptop"
+	group "osx-timemachine"
+	about "Shows all of the backups for the specified machine"
+	param "1: Machine name (optional)"
+	example "time-machine-list-all-backups my-laptop"
 
-  # Use the local hostname if none provided
-  local COMPUTERNAME=${1:-$(scutil --get ComputerName)}
-  local BACKUP_LOCATION="$(time-machine-destination)/Backups.backupdb/$COMPUTERNAME"
+	# Use the local hostname if none provided
+	local COMPUTERNAME BACKUP_LOCATION
+	COMPUTERNAME=${1:-$(scutil --get ComputerName)}
+	BACKUP_LOCATION="$(time-machine-destination)/Backups.backupdb/$COMPUTERNAME"
 
-  find "$BACKUP_LOCATION" -maxdepth 1 -mindepth 1 -type d | while read line ; do
-    echo "$line"
-  done
+	find "$BACKUP_LOCATION" -maxdepth 1 -mindepth 1 -type d | while read -r line; do
+		echo "$line"
+	done
 }
 
 function time-machine-list-old-backups() {
-  group "osx-timemachine"
-  about "Shows all of the backups for the specified machine, except for the most recent backup"
-  param "1: Machine name (optional)"
-  example "time-machine-list-old-backups my-laptop"
+	group "osx-timemachine"
+	about "Shows all of the backups for the specified machine, except for the most recent backup"
+	param "1: Machine name (optional)"
+	example "time-machine-list-old-backups my-laptop"
 
-  # Use the local hostname if none provided
-  local COMPUTERNAME=${1:-$(scutil --get ComputerName)}
-  local BACKUP_LOCATION="$(time-machine-destination)/Backups.backupdb/$COMPUTERNAME"
+	# Use the local hostname if none provided
+	local COMPUTERNAME BACKUP_LOCATION
+	COMPUTERNAME=${1:-$(scutil --get ComputerName)}
+	BACKUP_LOCATION="$(time-machine-destination)/Backups.backupdb/$COMPUTERNAME"
 
-  # List all but the most recent one
-  find "$BACKUP_LOCATION" -maxdepth 1 -mindepth 1 -type d -name 2\* | sed \$d | while read line ; do
-    echo "$line"
-  done
+	# List all but the most recent one
+	find "$BACKUP_LOCATION" -maxdepth 1 -mindepth 1 -type d -name 2\* | sed \$d | while read -r line; do
+		echo "$line"
+	done
 }
 
 # Taken from here: http://stackoverflow.com/a/30547074/1228454
 function _tm_startsudo() {
-    sudo -v
-    ( while true; do sudo -v; sleep 50; done; ) &
-    SUDO_PID="$!"
-    trap _tm_stopsudo SIGINT SIGTERM
+	local -x SUDO_COMMAND="plugin/osx-timemachine: keep 'sudo' token alive during long-run 'tmutil' commands"
+	sudo "-${SUDO_ASKPASS:+A}v" # validate without running a command, using `ssh-askpass` if available.
+	(while sudo "-${SUDO_ASKPASS:+A}v"; do
+		sleep 50
+	done) &
+	SUDO_PID="$!"
+	trap _tm_stopsudo SIGINT SIGTERM
 }
 function _tm_stopsudo() {
-    kill "$SUDO_PID"
-    trap - SIGINT SIGTERM
-    sudo -k
+	kill "$SUDO_PID"
+	trap - SIGINT SIGTERM
+	sudo -k
 }
 
 function time-machine-delete-old-backups() {
-  group "osx-timemachine"
-  about "Deletes all of the backups for the specified machine, with the exception of the most recent one"
-  param "1: Machine name (optional)"
-  example "time-machine-delete-old-backups my-laptop"
+	group "osx-timemachine"
+	about "Deletes all of the backups for the specified machine, with the exception of the most recent one"
+	param "1: Machine name (optional)"
+	example "time-machine-delete-old-backups my-laptop"
 
-  # Use the local hostname if none provided
-  local COMPUTERNAME=${1:-$(scutil --get ComputerName)}
+	# Use the local hostname if none provided
+	local COMPUTERNAME=${1:-$(scutil --get ComputerName)} _old_backup
 
-  # Ask for sudo credentials only once
-  _tm_startsudo
+	# Ask for sudo credentials only once
+	_tm_startsudo
 
-  echo "$(time-machine-list-old-backups "$COMPUTERNAME")" | while read i ; do
-    # Delete the backup
-    sudo tmutil delete "$i"
-  done
+	while read -r _old_backup; do
+		# Delete the backup
+		sudo tmutil delete "$_old_backup"
+	done <<< "$(time-machine-list-old-backups "$COMPUTERNAME")"
 
-  _tm_stopsudo
+	_tm_stopsudo
 }
diff --git a/plugins/available/osx.plugin.bash b/plugins/available/osx.plugin.bash
index ca1f66b8..139f58a1 100644
--- a/plugins/available/osx.plugin.bash
+++ b/plugins/available/osx.plugin.bash
@@ -1,23 +1,21 @@
-cite about-plugin
+# shellcheck shell=bash
 about-plugin 'osx-specific functions'
 
+if [[ "${OSTYPE}" != 'darwin'* ]]; then
+	_log_warning "This plugin only works with Mac OS X."
+	return 1
+fi
+
 # OS X: Open new tabs in same directory
-if [[ $OSTYPE == 'darwin'* ]]; then
-  if type update_terminal_cwd > /dev/null 2>&1 ; then
-    if ! [[ $PROMPT_COMMAND =~ (^|;)update_terminal_cwd($|;) ]] ; then
-      PROMPT_COMMAND="${PROMPT_COMMAND%;};update_terminal_cwd"
-      declared="$(declare -p PROMPT_COMMAND)"
-      [[ "$declared" =~ \ -[aAilrtu]*x[aAilrtu]*\  ]] 2>/dev/null
-      [[ $? -eq 0 ]] && export PROMPT_COMMAND
-    fi
-  fi
+if _is_function update_terminal_cwd; then
+	safe_append_prompt_command 'update_terminal_cwd'
 fi
 
 function tab() {
-  about 'opens a new terminal tab'
-  group 'osx'
+	about 'opens a new terminal tab'
+	group 'osx'
 
-  osascript 2>/dev/null <<EOF
+	osascript 2> /dev/null << EOF
     tell application "System Events"
       tell process "Terminal" to keystroke "t" using command down
     end
@@ -30,147 +28,105 @@ EOF
 
 # renames the current os x terminal tab title
 function tabname {
-  printf "\e]1;$1\a"
+	printf '%b' "\e]1;$1\a"
 }
 
 # renames the current os x terminal window title
 function winname {
-  printf "\e]2;$1\a"
+	printf '%b' "\e]2;$1\a"
 }
 
-# this one switches your os x dock between 2d and 3d
-# thanks to savier.zwetschge.org
-function dock-switch() {
-    about 'switch dock between 2d and 3d'
-    param '1: "2d" or "3d"'
-    example '$ dock-switch 2d'
-    group 'osx'
-
-    if [[ "$OSTYPE" = 'darwin'* ]]; then
-
-        if [[ $1 = 3d ]] ; then
-            defaults write com.apple.dock no-glass -boolean NO
-            killall Dock
-
-        elif [[ $1 = 2d ]] ; then
-            defaults write com.apple.dock no-glass -boolean YES
-            killall Dock
-
-        else
-            echo "usage:"
-            echo "dock-switch 2d"
-            echo "dock-switch 3d."
-        fi
-    else
-        echo "Sorry, this only works on Mac OS X"
-    fi
+function pman() {
+	about 'view man documentation in Preview'
+	param '1: man page to view'
+	example '$ pman bash'
+	group 'osx'
+	man -t "${1}" | open -fa 'Preview'
 }
 
-function pman ()
-{
-    about 'view man documentation in Preview'
-    param '1: man page to view'
-    example '$ pman bash'
-    group 'osx'
-    man -t "${1}" | open -fa $PREVIEW
-}
-
-function pri ()
-{
-    about 'display information about Ruby classes, modules, or methods, in Preview'
-    param '1: Ruby method, module, or class'
-    example '$ pri Array'
-    group 'osx'
-    ri -T "${1}" | open -fa $PREVIEW
+function pri() {
+	about 'display information about Ruby classes, modules, or methods, in Preview'
+	param '1: Ruby method, module, or class'
+	example '$ pri Array'
+	group 'osx'
+	ri -T "${1}" | open -fa 'Preview'
 }
 
 # Download a file and open it in Preview
 function prevcurl() {
-  about 'download a file and open it in Preview'
-  param '1: url'
-  group 'osx'
+	about 'download a file and open it in Preview'
+	param '1: url'
+	group 'osx'
 
-  if [[ ! $OSTYPE = 'darwin'* ]]
-  then
-    echo "This function only works with Mac OS X"
-    return 1
-  fi
-  curl "$*" | open -fa $PREVIEW
+	curl "$*" | open -fa 'Preview'
 }
 
 function refresh-launchpad() {
-  about 'Reset launchpad layout in macOS'
-  example '$ refresh-launchpad'
-  group 'osx'
+	about 'Reset launchpad layout in macOS'
+	example '$ refresh-launchpad'
+	group 'osx'
 
-  if [[ "$OSTYPE" = 'darwin'* ]];then
-    defaults write com.apple.dock ResetLaunchPad -bool TRUE
-    killall Dock
-  else
-    echo "Sorry, this only works on Mac OS X"
-  fi
+	defaults write com.apple.dock ResetLaunchPad -bool TRUE
+	killall Dock
 }
 
-function list-jvms(){
-  about 'List java virtual machines and their states in macOS'
-  example 'list-jvms'
-  group 'osx'
+function list-jvms() {
+	about 'List java virtual machines and their states in macOS'
+	example 'list-jvms'
+	group 'osx'
 
-  JVMS_DIR="/Library/Java/JavaVirtualMachines"
-  JVMS=( $(ls ${JVMS_DIR}) )
-  JVMS_STATES=()
+	local JVMS_DIR="/Library/Java/JavaVirtualMachines"
+	# The following variables are intended to impact the enclosing scope, not local.
+	JVMS=("${JVMS_DIR}"/*)
+	JVMS_STATES=()
 
-  # Map state of JVM
-  for (( i = 0; i < ${#JVMS[@]}; i++ )); do
-    if [[ -f "${JVMS_DIR}/${JVMS[$i]}/Contents/Info.plist" ]]; then
-      JVMS_STATES[${i}]=enabled
-    else
-      JVMS_STATES[${i}]=disabled
-    fi
-      echo "${i} ${JVMS[$i]} ${JVMS_STATES[$i]}"
-  done
+	# Map state of JVM
+	for ((i = 0; i < ${#JVMS[@]}; i++)); do
+		if [[ -f "${JVMS[i]}/Contents/Info.plist" ]]; then
+			JVMS_STATES[i]=enabled
+		else
+			JVMS_STATES[i]=disabled
+		fi
+		printf '%s\t%s\t%s\n' "${i}" "${JVMS[i]##*/}" "${JVMS_STATES[i]}"
+	done
 }
 
-function pick-default-jvm(){
-  about 'Pick the default Java Virtual Machines in system-wide scope in macOS'
-  example 'pick-default-jvm'
+function pick-default-jvm() {
+	about 'Pick the default Java Virtual Machines in system-wide scope in macOS'
+	example 'pick-default-jvm'
 
-  # Call function for listing
-  list-jvms
+	# Declare variables
+	local JVMS JVMS_STATES
+	local DEFAULT_JVM_DIR DEFAULT_JVM OPTION
 
-  # Declare variables
-  local DEFAULT_JVM_DIR=""
-  local DEFAULT_JVM=""
-  local OPTION=""
+	# Call function for listing
+	list-jvms
 
-  # OPTION for default jdk and set variables
-  while [[ ! "$OPTION" =~ ^[0-9]+$ || OPTION -ge "${#JVMS[@]}" ]]; do
-    read -p "Enter Default JVM: "  OPTION
-      if [[ ! "$OPTION" =~ ^[0-9]+$  ]]; then
-        echo "Please enter a number"
-      fi
+	# OPTION for default jdk and set variables
+	while [[ ! "$OPTION" =~ ^[0-9]+$ || OPTION -ge "${#JVMS[@]}" ]]; do
+		read -rp "Enter Default JVM: " OPTION
+		if [[ ! "$OPTION" =~ ^[0-9]+$ ]]; then
+			echo "Please enter a number"
+		fi
 
-      if [[ OPTION -ge "${#JVMS[@]}" ]]; then
-        echo "Please select one of the displayed JVMs"
-      fi
-  done
+		if [[ OPTION -ge "${#JVMS[@]}" ]]; then
+			echo "Please select one of the displayed JVMs"
+		fi
+	done
 
-  DEFAULT_JVM_DIR="${JVMS_DIR}/${JVMS[$OPTION]}"
-  DEFAULT_JVM="${JVMS[$OPTION]}"
+	DEFAULT_JVM_DIR="${JVMS[OPTION]}"
+	DEFAULT_JVM="${JVMS[OPTION]##*/}"
 
-  # Disable all jdk
-  for (( i = 0; i < ${#JVMS[@]}; i++ )); do
-    if [[ -f "${JVMS_DIR}/${JVMS[$i]}/Contents/Info.plist" ]]; then
-      sudo mv "${JVMS_DIR}/${JVMS[$i]}/Contents/Info.plist" "${JVMS_DIR}/${JVMS[$i]}/Contents/Info.plist.disable"
-    fi
-  done
+	# Disable all jdk
+	for ((i = 0; i < ${#JVMS[@]}; i++)); do
+		if [[ "${JVMS[i]}" != "${DEFAULT_JVM_DIR}" && -f "${JVMS[i]}/Contents/Info.plist" ]]; then
+			sudo mv "${JVMS[i]}/Contents/Info.plist" "${JVMS[i]}/Contents/Info.plist.disable"
+		fi
+	done
 
-  # Enable default jdk
-  if [[ -f "${DEFAULT_JVM_DIR}/Contents/Info.plist.disable" ]]; then
-    sudo mv "${DEFAULT_JVM_DIR}/Contents/Info.plist.disable" "${DEFAULT_JVM_DIR}/Contents/Info.plist"
-    echo "Enabled ${DEFAULT_JVM} as default JVM"
-  fi
+	# Enable default jdk
+	if [[ -f "${DEFAULT_JVM_DIR}/Contents/Info.plist.disable" ]]; then
+		sudo mv -vn "${DEFAULT_JVM_DIR}/Contents/Info.plist.disable" "${DEFAULT_JVM_DIR}/Contents/Info.plist" \
+			&& echo "Enabled ${DEFAULT_JVM} as default JVM"
+	fi
 }
-
-# Make this backwards compatible
-alias pcurl='prevcurl'
diff --git a/test/run b/test/run
index fe4ac847..7999d4fb 100755
--- a/test/run
+++ b/test/run
@@ -11,7 +11,7 @@ if [ -z "${BASH_IT}" ]; then
 fi
 
 if [ -z "$1" ]; then
-  test_dirs=( ${test_directory}/{bash_it,completion,install,lib,plugins,themes} )
+  test_dirs=( "${test_directory}"/{bash_it,completion,install,lib,plugins,themes} )
 else
   test_dirs=( "$1" )
 fi