tmp.txt

diff --git a//Makefile b//Makefile
index 7a5a05f..464892b 100644
--- a/Makefile	
+++ b/Makefile	
@@ -183,6 +183,7 @@ UPROGS=\
 	_sh\
 	_shutdown\
 	_stressfs\
+	_time\
 	_userp\
 	_usertests\
 	_wc\
@@ -258,7 +259,7 @@ EXTRA=\
 	ln.c ls.c mkdir.c rm.c stressfs.c usertests.c wc.c zombie.c\
 	printf.c umalloc.c\
 	README dot-bochsrc *.pl toc.* runoff runoff1 runoff.list\
-	.gdbinit.tmpl gdbutil userp.c add.c date.c shutdown.c\
+	.gdbinit.tmpl gdbutil userp.c add.c date.c shutdown.c time.c\
 
 dist:
 	rm -rf dist
diff --git a/Operating System/xv6 Practice/xv6-public/time.c b/Operating System/xv6 Practice/xv6-public/time.c
new file mode 100644
index 0000000..ff399ee
--- /dev/null
+++ b/Operating System/xv6 Practice/xv6-public/time.c	
@@ -0,0 +1,28 @@
+#include "types.h"
+#include "user.h"
+
+
+int
+main(int argc, char * argv[])
+{
+	int startTicks = uptime();
+	int x = fork();
+	if(x<0)
+	{
+		printf(1,"fork failed\n");
+		exit();
+	}
+	else if(x==0)
+	{
+		if(argc == 1)
+			exit();
+		exec(argv[1] , argv+1);
+	}
+	else
+	{
+		wait();
+		int stopTicks = uptime();
+		printf(1,"\ntime: %d ticks\n",stopTicks-startTicks);
+		exit();
+	}
+}
\ No newline at end of file