From ef0963b824205103ed0d3dab50934f72f5923c5c Mon Sep 17 00:00:00 2001
From: Scott Worley <scottworley@scottworley.com>
Date: Thu, 23 Feb 2023 19:02:44 -0800
Subject: [PATCH] Make filenames from dir name

---
 batteryviewer.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/batteryviewer.c b/batteryviewer.c
index 540db8e..9f1dedd 100644
--- a/batteryviewer.c
+++ b/batteryviewer.c
@@ -1,11 +1,27 @@
+// For vasprintf
+#define _GNU_SOURCE
+
 #include "chart.h"
 #include <ctype.h>
 #include <errno.h>
 #include <gtk/gtk.h>
 #include <math.h>
+#include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 
+char *sasprintf(const char *fmt, ...) {
+  char *result;
+  va_list args;
+  va_start(args, fmt);
+  if (vasprintf(&result, fmt, args) == -1) {
+    fprintf(stderr, "Can't allocate memory!?\n");
+    abort();
+  }
+  va_end(args);
+  return result;
+}
+
 struct State {
   char *voltage_filename;
   char *current_filename;
@@ -79,9 +95,10 @@ static void activate(GtkApplication *app, gpointer user_data) {
 }
 
 int main(int argc, char **argv) {
+  char *battery_dir = "/sys/class/power_supply/BAT0";
   struct State state = {
-      .voltage_filename = "/sys/class/power_supply/BAT0/voltage_now",
-      .current_filename = "/sys/class/power_supply/BAT0/current_now",
+      .voltage_filename = sasprintf("%s/voltage_now", battery_dir),
+      .current_filename = sasprintf("%s/current_now", battery_dir),
   };
 
   GtkApplication *app = gtk_application_new("com.scottworley.batteryviewer",
-- 
2.44.1