feat: improve help

src/main.zig

@@ -13,6 +13,7 @@ pub fn main() !void {
     defer std.process.argsFree(allocator, args);
 
     var target: u8 = 15;
+    var battery: []const u8 = "BAT0";
 
     for (args, 0..) |arg, i| {
         if (std.mem.eql(u8, arg, "--help")) {
@@ -21,7 +22,8 @@ pub fn main() !void {
                 \\Usage: bat-alert [options]
                 \\
                 \\Options:
-                \\  -t, --target NUM	Target battery level
+                \\  -t, --target NUM	Target battery level (default: 15)
+                \\  --battery NAME		Battery name (default: BAT0)
                 \\
             , .{});
             std.process.exit(0);
@@ -39,12 +41,22 @@ pub fn main() !void {
             };
             target = parsedTarget;
         }
+
+        if (std.mem.eql(u8, arg, "--battery")) {
+            if (i + 1 == args.len) {
+                std.log.err("--battery requires an argument", .{});
+                std.process.exit(1);
+            }
+
+            battery = args[i + 1];
+        }
     }
 
     var sent = false;
+    const batteryPath = try std.fmt.allocPrint(allocator, "/sys/class/power_supply/{s}/capacity", .{battery});
 
     while (true) {
-        const capacityFile = try std.fs.openFileAbsolute("/sys/class/power_supply/BAT0/capacity", .{});
+        const capacityFile = try std.fs.openFileAbsolute(batteryPath, .{});
         var capacityStr = std.ArrayList(u8).init(allocator);
         try capacityFile.reader().streamUntilDelimiter(capacityStr.writer(), '\n', null);
         capacityFile.close();
@@ -66,6 +78,7 @@ pub fn main() !void {
         } else {
             sent = false;
         }
+        capacityStr.deinit();
 
         std.time.sleep(10 * 1e9);
     }