added battery prompt segment usable on OS X systems

README.md

@@ -71,6 +71,7 @@ configuration is the default:
 The segments that are currently available are:
 
 * [aws](#aws) - The current AWS profile, if active.
+* [battery](#battery) - Current battery status(OS X only).
 * [context](#context) - Your username and host.
 * [dir](#dir) - Your current working directory.
 * **history** - The command number for the current line.
@@ -101,6 +102,22 @@ your `~/.zshrc`:
 
     export AWS_DEFAULT_PROFILE=<profile_name>
 
+##### battery
+
+This segment will display your current battery status on an OS X system(fails gracefully
+on systems without a battery and non OS X systems). It can be customized in your .zshrc
+with the environment variables detailed below with their default values.
+
+    POWERLEVEL9K_BATTERY_CHARGING="yellow"
+    POWERLEVEL9K_BATTERY_CHARGED="green"
+    POWERLEVEL9K_BATTERY_DISCONNECTED=$DEFAULT_COLOR
+    POWERLEVEL9K_BATTERY_LOW_THRESHOLD=10
+    POWERLEVEL9K_BATTERY_LOW_COLOR="red"
+
+In addition to the above it supports standard _FOREGROUND value without affecting the icon color
+
+
+
 ##### context
 
 The `context` segment (user@host string) is conditional. This lets you enable it, but only display

powerlevel9k.zsh-theme

@@ -46,6 +46,7 @@ case $POWERLEVEL9K_MODE in
       BACKGROUND_JOBS_ICON           $'\UE82F '             # 
       TEST_ICON                      $'\UE891'              # 
       TODO_ICON                      $'\U2611'              # ☑
+      BATTERY_ICON                   $'\UE894'              # 
       OK_ICON                        $'\U2713'              # ✓
       FAIL_ICON                      $'\U2718'              # ✘
       SYMFONY_ICON                   'SF'
@@ -95,6 +96,7 @@ case $POWERLEVEL9K_MODE in
       BACKGROUND_JOBS_ICON           $'\UF013 '             # 
       TEST_ICON                      $'\UF291'              # 
       TODO_ICON                      $'\U2611'              # ☑
+      BATTERY_ICON                   $'\u1F50B'             # 🔋
       OK_ICON                        $'\UF23A'              # 
       FAIL_ICON                      $'\UF281'              # 
       SYMFONY_ICON                   'SF'
@@ -139,6 +141,7 @@ case $POWERLEVEL9K_MODE in
       BACKGROUND_JOBS_ICON           $'\u2699'              # ⚙
       TEST_ICON                      ''
       TODO_ICON                      $'\U2611'              # ☑
+      BATTERY_ICON                   $'\u1F50B'             # 🔋
       OK_ICON                        $'\u2713'              # ✓
       FAIL_ICON                      $'\u2718'              # ✘
       SYMFONY_ICON                   'SF'
@@ -611,6 +614,48 @@ prompt_aws() {
   fi
 }
 
+prompt_battery() {
+  if [[ -f /usr/sbin/ioreg && -x /usr/sbin/ioreg ]]; then
+    # return if there is no battery on system
+    [[ -z $(ioreg -n AppleSmartBattery | grep MaxCapacity) ]] && return
+
+    # set default values of not specified in shell
+    [[ -z $POWERLEVEL9K_BATTERY_CHARGING ]] && POWERLEVEL9K_BATTERY_CHARGING="yellow"
+    [[ -z $POWERLEVEL9K_BATTERY_CHARGED ]] && POWERLEVEL9K_BATTERY_CHARGED="green"
+    [[ -z $POWERLEVEL9K_BATTERY_DISCONNECTED ]] && POWERLEVEL9K_BATTERY_DISCONNECTED="$DEFAULT_COLOR"
+    [[ -z $POWERLEVEL9K_BATTERY_LOW_THRESHOLD ]] && POWERLEVEL9K_BATTERY_LOW_THRESHOLD=10
+    [[ -z $POWERLEVEL9K_BATTERY_LOW_COLOR ]] && POWERLEVEL9K_BATTERY_LOW_COLOR="red"
+    [[ -z $POWERLEVEL9K_BATTERY_FOREGROUND ]] && local fg_color="$DEFAULT_COLOR" || local fg_color=$POWERLEVEL9K_BATTERY_FOREGROUND
+
+    # get charge status
+    [[ $(ioreg -n AppleSmartBattery | grep ExternalConnected | awk '{ print $5 }') =~ "Yes" ]] && local connected=true
+    [[ $(ioreg -n AppleSmartBattery | grep IsCharging | awk '{ print $5 }') =~ "Yes" ]] && local charging=true
+
+    # convert time remaining from minutes to hours:minutes date string
+    local time_remaining=$(ioreg -n AppleSmartBattery | grep TimeRemaining | awk '{ print $5 }')
+    if [[ ! -z $time_remaining ]]; then
+      # this value is set to a very high number when the system is calculating
+      [[ $time_remaining -gt 10000 ]] && local tstring="..." || local tstring=${(f)$(date -u -r $(($time_remaining * 60)) +%k:%M)}
+    fi
+
+    # get charge values
+    local max_capacity=$(ioreg -n AppleSmartBattery | grep MaxCapacity | awk '{ print $5 }')
+    local current_capacity=$(ioreg -n AppleSmartBattery | grep CurrentCapacity | awk '{ print $5 }')
+
+    # logic for string output
+    [[ ! -z $max_capacity && ! -z $current_capacity ]] && local bat_percent=$(ruby -e "puts ($current_capacity.to_f / $max_capacity.to_f * 100).round.to_i")
+    [[ $charging =~ true && $connected =~ true ]] && local conn="%F{$POWERLEVEL9K_BATTERY_CHARGING}" && local remain="($tstring)"
+    [[ ! $charging =~ true && $connected =~ true ]] && local conn="%F{$POWERLEVEL9K_BATTERY_CHARGED}" && local remain=""
+    if [[ ! $connected =~ true ]]; then
+      [[ $bat_percent -lt $POWERLVEL9K_BATTERY_LOW_THRESHOLD ]] && local conn="%F{$POWERLEVEL9K_BATTERY_LOW_COLOR}" || local conn="%F{$POWERLEVEL9K_BATTERY_DISCONNECTED}"
+      local remain="($tstring)"
+    fi
+
+    # display prompt_segment
+    [[ ! -z $bat_percent ]] && "$1_prompt_segment" "$0" "black" "$DEFAULT_COLOR" "$conn$(print_icon 'BATTERY_ICON'){$fg_color} $bat_percent%% $remain"
+  fi
+}
+
 # Context: user@hostname (who am I and where am I)
 # Note that if $DEFAULT_USER is not set, this prompt segment will always print
 prompt_context() {