diff --git a/.gitignore b/.gitignore
index 68169da..01ab412 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,4 @@ limit
 runner
 CMakeLists.txt
 main
+demo/out
diff --git a/README.md b/README.md
index ee45727..97f72b4 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1,13 @@
 
+#Judger
+
 [![Build Status](https://travis-ci.org/QingdaoU/Judger.svg?branch=master)](https://travis-ci.org/QingdaoU/Judger)
 
+
+OnlineJudge 判题沙箱
+
+demo:
 ```
 sudo python setup.py install
-touch in out
-gcc test.c -o test
-sudo python demo.py
+cd demo && sudo python demo.py
 ```
diff --git a/demo.py b/demo.py
deleted file mode 100644
index 0049b46..0000000
--- a/demo.py
+++ /dev/null
@@ -1,17 +0,0 @@
-# coding=utf-8
-import os
-import judger
-
-
-base_path = os.path.dirname(os.path.abspath(__file__))
-
-
-print judger.run(path=os.path.join(base_path, "test"),
-                 in_file=os.path.join(base_path, "in"),
-                 out_file=os.path.join(base_path, "out"),
-                 max_cpu_time=2000,
-                 max_memory=200000000,
-                 args=["1", "2", "####"], 
-                 env=[],
-                 use_sandbox=True)
-
diff --git a/demo/demo.c b/demo/demo.c
new file mode 100644
index 0000000..13c4fcb
--- /dev/null
+++ b/demo/demo.c
@@ -0,0 +1,32 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+int main(int argc, char *argv[]) {
+    int *p = NULL;
+    int j;
+    char input[100];
+    // 150M
+    int v = 150000000;
+
+    printf("start\n");
+
+    for (j = 0; j < argc; j++)
+        printf("argv[%d]: %s\n", j, argv[j]);
+
+    scanf("%s", input);
+    printf("%s\n", input);
+
+    p = (int *) malloc(v);
+    if (p == NULL) {
+        printf("malloc failed\n");
+    }
+    else {
+        memset(p, 0, v);
+        printf("malloc succeeded\n");
+    }
+    printf("begin to execute command\n");
+    system("/bin/ls /tmp");
+    return 0;
+}
diff --git a/demo/demo.py b/demo/demo.py
new file mode 100644
index 0000000..cd32ac2
--- /dev/null
+++ b/demo/demo.py
@@ -0,0 +1,28 @@
+# coding=utf-8
+import os
+import judger
+
+base_path = os.path.dirname(os.path.abspath(__file__))
+
+
+def run(use_sandbox):
+    os.system("gcc demo.c -o demo")
+    path = os.path.join(base_path, "demo")
+    return judger.run(path=path,
+                      in_file=os.path.join(base_path, "in"),
+                      out_file=os.path.join(base_path, "out"),
+                      # ms
+                      max_cpu_time=2000,
+                      # Byte
+                      max_memory=200000000,
+                      # args and env are optional
+                      args=["1", "2", "####"],
+                      env=["aaa=123"],
+                      # default is True
+                      use_sandbox=use_sandbox)
+
+
+print "With sandbox"
+print run(use_sandbox=True)
+print 'Without sandbox'
+print run(use_sandbox=False)
diff --git a/demo/in b/demo/in
new file mode 100644
index 0000000..70c379b
--- /dev/null
+++ b/demo/in
@@ -0,0 +1 @@
+Hello world
\ No newline at end of file
diff --git a/judger.c b/judger.c
index aa5e414..9a679a2 100644
--- a/judger.c
+++ b/judger.c
@@ -33,6 +33,7 @@ static PyObject *judger_run(PyObject *self, PyObject *args, PyObject *kwargs) {
         PyErr_SetString(PyExc_ValueError, "Input file does not exist");
         return NULL;
     }
+    config.args[count++] = config.path;
     if (args_list != NULL) {
         if (!PyList_Check(args_list)) {
             PyErr_SetString(PyExc_ValueError, "args must be a list");
diff --git a/test.c b/test.c
deleted file mode 100644
index 6b93fd0..0000000
--- a/test.c
+++ /dev/null
@@ -1,28 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-int main(int argc, char *argv[]) {
-    int *a = NULL;
-    int j;
-    char *newargv[] = {"/", NULL};
-    char *env[] = {NULL};
-    printf("start\n");
-    // 150M
-    int v = 150000000;
-    //fork();
-    // printf("%s\n", getenv("LD_PRELOAD"));
-    for (j = 0; j < argc; j++)
-                   printf("argv[%d]: %s\n", j, argv[j]);
-    //execve("/bin/echo", newargv, env);
-    a = (int *) malloc(v);
-    if (a == NULL) {
-        printf("error\n");
-    }
-    else {
-        memset(a, 0, v);
-        printf("success\n");
-    }
-    printf("end\n");
-    return 0;
-}