diff --git a/src/main/java/com/github/hcsp/shell/Fork.java b/src/main/java/com/github/hcsp/shell/Fork.java
index 28e0700..6c4add1 100644
--- a/src/main/java/com/github/hcsp/shell/Fork.java
+++ b/src/main/java/com/github/hcsp/shell/Fork.java
@@ -3,6 +3,7 @@
 import java.io.File;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.Map;
 
 public class Fork {
     public static void main(String[] args) throws Exception {
@@ -10,6 +11,13 @@ public static void main(String[] args) throws Exception {
         // 工作目录是项目目录下的working-directory目录（可以用getWorkingDir()方法得到这个目录对应的File对象）
         // 传递的命令是sh run.sh
         // 环境变量是AAA=123
+
+        ProcessBuilder p = new ProcessBuilder("sh", "run.sh");
+        p.directory(getWorkingDir());
+        Map<String, String> envs = p.environment();
+        envs.put("AAA", "123");
+        p.redirectOutput(getOutputFile());
+        p.start().waitFor();
     }
 
     private static File getWorkingDir() {
diff --git a/working-directory/output.txt b/working-directory/output.txt
index e69de29..5d8bb42 100644
--- a/working-directory/output.txt
+++ b/working-directory/output.txt
@@ -0,0 +1,7 @@
+AAA is: 123
+total 40
+-rw-r--r--   1 a  staff    12B Oct 20 08:44 output.txt
+drwxr-xr-x  12 a  staff   384B Oct 20 08:44 ..
+-rw-r--r--   1 a  staff    47B Oct 19 17:33 run.sh
+drwxr-xr-x   5 a  staff   160B Oct 19 17:33 .
+-rw-r--r--   1 a  staff    11K Oct 19 17:33 .hidden.txt