Lab util: uptime

Author: foyoodo

Makefile

@@ -149,6 +149,7 @@ UPROGS=\
 	$U/_sh\
 	$U/_sleep\
 	$U/_stressfs\
+	$U/_uptime\
 	$U/_usertests\
 	$U/_grind\
 	$U/_wc\

user/uptime.c

@@ -0,0 +1,16 @@
+#include "kernel/types.h"
+#include "user/user.h"
+
+int
+main(int argc, char *argv[])
+{
+
+  if (argc > 1) {
+    fprintf(2, "Usage: uptime\n");
+    exit(1);
+  }
+
+  fprintf(1, "%d ticks\n", uptime());
+
+  exit(0);
+}