add config for slstatus

config_files/slstatus/config.h

@@ -0,0 +1,11 @@
+const unsigned int interval = 1000;
+static const char unknown_str[] = "n/a";
+#define MAXLEN 2048
+static const struct arg args[] = {
+	{ run_command, 		"VOL: %s | ",	"wpctl get-volume @DEFAULT_AUDIO_SINK@ | sed 's/Volume: //'" },
+	{ disk_free, 		"FDS: %s | ",	"/" },
+	{ cpu_perc, 		"CPU: %s%% | ", NULL },
+	{ battery_state,	"BAT: %s ",	"BAT0" },
+	{ battery_perc,		"%s%% | ", 	"BAT0" },
+	{ datetime,		"%s",           "%F %T" },
+};

overlays.nix

@@ -38,4 +38,8 @@
       buildInputs = oldAttrs.buildInputs ++ [ prev.pkgs.glib ];
     });
   })
+
+  (final: prev: {
+    slstatus = prev.slstatus.override { conf = ./config_files/slstatus/config.h; };
+  })
 ]