added cpu usage to statline

makefile now has configurable options

dwm-stat/Makefile

@@ -1,11 +1,19 @@
+# Here are the configuraable options 
+# LAPTOP 	: enable batter level
+# CPU_USAGE : CPU usage in percentage
+# DEBUG 	: for fixing issues
+
+# NOTE: the -D is needed for gcc
+# MFLAGS= -D MY_OPTION -D ANOTHER_OPT ...
+MFLAGS=-D LAPTOP -D CPU_USAGE
+
+
 flags=-O2 -s -lX11
 output=statline
-stat:
-	gcc -o $(output) status.c $(flags)
 
-laptop:
+
-	# compiling with LAPTOP=1
+stat:
-	gcc -D LAPTOP=1 status.c -o $(output) $(flags)
+	gcc $(MFLAGS) -o $(output) status.c $(flags)
 
 run:
 	./statline

dwm-stat/status.c

@@ -20,6 +20,7 @@
 // Time in seconds
 #define TIME_DELAY 5
 #define MAXSTR 1024
+#define SMALL_BUF 32
 
 #define MEM_BREAD_SIZE 32
 #define STD_IO
@@ -91,11 +92,39 @@ battery_percentage(void)
 #endif
 
 
+#ifdef CPU_USAGE
+// stat(2) ->
+#define CPU_PROC_BASE
+#define TOTAL "head /proc/stat -n 1 | cut -c 6- | sed 's/ /\\+/g' | bc"
+#define IDLE "head /proc/stat -n 1 | cut -c 6- | awk '{print $4}'"
 static char* 	
 cpu_usage(void)
 {
-	return "CPU Usage Placeholder";
+	// NOTE: not accounting for the query so this may be somewhat off by some metric
+	// Grabbing the total usage
+	FILE* query_p;
+	static char buf[SMALL_BUF];
+	unsigned total, idle;
+	// get the total time
+	query_p = popen(TOTAL, "r");
+	fgets(buf, sizeof(buf)-1, query_p);
+	total = atoi(buf);
+	pclose(query_p);
+
+	// get the idle time
+	query_p = popen(IDLE, "r");
+	fgets(buf, sizeof(buf)-1, query_p);
+	idle = atoi(buf);
+	pclose(query_p);
+
+	double usage = 1.00 - ((double)idle / (double)total);
+#ifdef DEBUG
+	printf("IDLE/TOTAL = %.02f\n", usage);
+#endif
+	sprintf(buf, "CPU: %.02f % ", usage);
+	return buf;
 }
+#endif
 
 static void 
 XSetRoot(char* name)
@@ -122,6 +151,9 @@ main(void)
 		date_time, 
 #ifdef LAPTOP
 		battery_percentage,
+#endif
+#ifdef CPU_USAGE
+		cpu_usage,
 #endif
 	};