Remove subshells in _lp_battery()

_lp_battery() now returns the battery percentage in lp_battery.
It also returns 5 when disabled (still 4 when full or no data).
_lp_battery_color() now returns the formatted string in
lp_battery_color.
It also returns 2 when disabled (still 1 when no string returned).
Add a version of _lp_battery() for when OS is not Linux or Darwin that
only returns 5.

liquidprompt

@@ -1362,58 +1362,61 @@ _lp_wifi() {
 # returns 2 (and battery level) if battery is charging but under threshold
 # returns 3 (and battery level) if battery is charging and above threshold
 # returns 4 if no battery support
+# returns 5 if disabled
 case "$LP_OS" in
     Linux)
     _lp_battery() {
-        (( LP_ENABLE_BATT )) || return 4
+        (( LP_ENABLE_BATT )) || return 5
         local acpi
         acpi="$(acpi --battery 2>/dev/null)"
         # Extract the battery load value in percent
         # First, remove the beginning of the line...
-        local bat="${acpi#Battery *, }"
-        bat="${bat%%%*}" # remove everything starting at '%'
+        lp_battery="${acpi#Battery *, }"
+        lp_battery="${lp_battery%%%*}" # remove everything starting at '%'
 
-        if [[ -z "${bat}" ]]; then
+        if [[ -z "${lp_battery}" ]]; then
             # no battery level found
             return 4
         fi
-        echo -nE "$bat"
         # discharging
         if [[ "$acpi" == *"Discharging"* ]]; then
             # under => 0, above => 1
-            return $(( bat > LP_BATTERY_THRESHOLD ))
+            return $(( lp_battery > LP_BATTERY_THRESHOLD ))
         # not charging
         elif [[ "$acpi" == *"Not charging"* ]]; then
             return 4
         # charging
         else
             # under => 2, above => 3
-            return $(( 2 + ( bat > LP_BATTERY_THRESHOLD ) ))
+            return $(( 2 + ( lp_battery > LP_BATTERY_THRESHOLD ) ))
         fi
     }
     ;;
     Darwin)
     _lp_battery() {
-        (( LP_ENABLE_BATT )) || return 4
+        (( LP_ENABLE_BATT )) || return 5
         local percent batt_status
-        eval "$(pmset -g batt | sed -n 's/^ -InternalBattery.*[[:space:]]\([0-9]*[0-9]\)%; \([^;]*\).*$/percent=\1 batt_status='\'\\2\'/p)"
+        eval "$(pmset -g batt | sed -n 's/^ -InternalBattery.*[[:space:]]\([0-9]*[0-9]\)%; \([^;]*\).*$/lp_battery=\1 batt_status='\'\\2\'/p)"
         case "$batt_status" in
             charged | "")
             return 4
             ;;
             discharging)
-                echo -nE "$percent"
                 # under => 0, above => 1
-                return $(( percent > LP_BATTERY_THRESHOLD ))
+                return $(( lp_battery > LP_BATTERY_THRESHOLD ))
             ;;
             *)  # "charging", "AC attached"
-                echo -nE "$percent"
                 # under => 2, above => 3
-                return $(( 2 + ( percent > LP_BATTERY_THRESHOLD ) ))
+                return $(( 2 + ( lp_battery > LP_BATTERY_THRESHOLD ) ))
             ;;
         esac
     }
     ;;
+    *)
+    _lp_battery() {
+        return 5
+    }
+    ;;
 esac
 
 # Compute a gradient of background/foreground colors depending on the battery status
@@ -1423,33 +1426,33 @@ esac
 # a yellow ⌁ if the battery is discharging but above threshold
 # a    red ⌁ if the battery is discharging and above threshold
 _lp_battery_color() {
-    (( LP_ENABLE_BATT )) || return
+    (( LP_ENABLE_BATT )) || return 2
 
     local mark=$LP_MARK_BATTERY
     local chargingmark=$LP_MARK_ADAPTER
     local -i bat ret
-    bat="$(_lp_battery)"
+    _lp_battery
     ret=$?
+    bat=$lp_battery
 
-    if (( ret == 4 || bat == 100 )); then
+    if (( ret >= 4 || bat == 100 )); then
         # no battery support or battery full: nothing displayed
-        :
+        return 1
     elif (( ret == 3 && bat != 100 )); then
         # charging and above threshold and not 100%
         # green ⏚
-        echo -nE "${LP_COLOR_CHARGING_ABOVE}$chargingmark${NO_COL}"
+        lp_battery_color="${LP_COLOR_CHARGING_ABOVE}$chargingmark${NO_COL}"
     elif (( ret == 2 )); then
         # charging but under threshold
         # yellow ⏚
-        echo -nE "${LP_COLOR_CHARGING_UNDER}$chargingmark${NO_COL}"
+        lp_battery_color="${LP_COLOR_CHARGING_UNDER}$chargingmark${NO_COL}"
     elif (( ret == 1 )); then
         # discharging but above threshold
         # yellow ⌁
-        echo -nE "${LP_COLOR_DISCHARGING_ABOVE}$mark${NO_COL}"
+        lp_battery_color="${LP_COLOR_DISCHARGING_ABOVE}$mark${NO_COL}"
     # discharging and under threshold
     else
-        local res
-        res="${LP_COLOR_DISCHARGING_UNDER}${mark}${NO_COL}"
+        lp_battery_color="${LP_COLOR_DISCHARGING_UNDER}${mark}${NO_COL}"
 
         if (( LP_PERCENTS_ALWAYS )); then
             local -i idx
@@ -1477,9 +1480,8 @@ _lp_battery_color() {
                 idx=0
             fi
 
-            res+="${LP_COLORMAP[idx+_LP_FIRST_INDEX]}${bat}$_LP_PERCENT${NO_COL}"
+            lp_battery_color+="${LP_COLORMAP[idx+_LP_FIRST_INDEX]}${bat}$_LP_PERCENT${NO_COL}"
         fi # LP_PERCENTS_ALWAYS
-        echo -nE "${res}"
     fi
 }
 
@@ -1769,7 +1771,11 @@ _lp_theme_prompt() {
     fi
     LP_TEMP="$(_lp_sr "$(_lp_temperature)")"
     LP_LOAD="$(_lp_sr "$(_lp_load_color)")"
-    LP_BATT="$(_lp_sr "$(_lp_battery_color)")"
+    if _lp_battery_color; then
+        LP_BATT="$lp_battery_color "
+    else
+        LP_BATT=
+    fi
     _lp_time
     _lp_sudo_check