From ad92c60d6b3263888652762e4d90e67ed45a1563 Mon Sep 17 00:00:00 2001
From: Vilmos Nebehaj <v.nebehaj@gmail.com>
Date: Sun, 9 Mar 2014 14:03:36 +0100
Subject: [PATCH] Compute mean percentage for multiple batteries.

If a laptop has multiple batteries, compute the mean percentage if the
user asks for 'all' instead of a specific battery.
---
 src/linux.cc | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/linux.cc b/src/linux.cc
index 30536778..684bfed3 100644
--- a/src/linux.cc
+++ b/src/linux.cc
@@ -2095,7 +2095,8 @@ void get_battery_short_status(char *buffer, unsigned int n, const char *bat)
 int get_battery_perct(const char *bat)
 {
 	static int rep = 0;
-	int idx;
+	int idx, n = 0, total_capacity = 0;
+	char battery[8];
 	char acpi_path[128];
 	char sysfs_path[128];
 	int remaining_capacity = -1;
@@ -2105,6 +2106,22 @@ int get_battery_perct(const char *bat)
 
 	init_batteries();
 
+	if (!strcmp(bat, "all")) {
+		for (idx = 0; idx < MAX_BATTERY_COUNT; idx++) {
+			snprintf(battery, sizeof(battery) - 1, "BAT%d", idx);
+			remaining_capacity = get_battery_perct(battery);
+			if (remaining_capacity > 0) {
+				total_capacity += remaining_capacity;
+				n++;
+			}
+		}
+
+		if (n == 0)
+			return 0;
+		else
+			return total_capacity / n;
+	}
+
 	idx = get_battery_idx(bat);
 
 	/* don't update battery too often */