diff --git a/bash-5.1/r_variables/src/lib.rs b/bash-5.1/r_variables/src/lib.rs
index cb0e1fede3d3b90135e2fd865a6ca66b5cb7ca6c..d4364a959b28d268f99833fa01f687f465cc633b 100644
--- a/bash-5.1/r_variables/src/lib.rs
+++ b/bash-5.1/r_variables/src/lib.rs
@@ -166,3 +166,42 @@ unsafe extern "C" fn create_variable_tables() {
         shell_function_defs = hash_create(FUNCTIONS_HASH_BUCKETS!() as libc::c_int);
     }
 }
+
+#[no_mangle]
+pub unsafe extern "C" fn sh_get_home_dir() -> *mut libc::c_char {
+    
+    if (current_user.home_dir).is_null() {
+        // get_current_user_info  in file of shell.c
+        get_current_user_info();
+    }
+    return current_user.home_dir;
+}
+
+unsafe extern "C" fn set_home_var() {
+    let mut temp_var: *mut SHELL_VAR = 0 as *mut SHELL_VAR;
+    // find_variable  下文会实现
+    temp_var = find_variable(b"HOME\0" as *const u8 as *const libc::c_char);
+    if temp_var.is_null() {
+        temp_var =bind_variable(
+            b"HOME\0" as *const u8 as *const libc::c_char,
+            sh_get_home_dir(),
+            0 as libc::c_int);
+    }
+}
+
+unsafe extern "C" fn set_shell_var() {
+    let mut temp_var: *mut SHELL_VAR = 0 as *mut SHELL_VAR;
+    // find_variable  下文会实现
+    temp_var = find_variable(b"SHELL\0" as *const u8 as *const libc::c_char);
+    if temp_var.is_null() {
+        if (current_user.shell).is_null() {
+            // get_current_user_info  in file of shell.c
+            get_current_user_info();
+        }
+        temp_var =bind_variable(
+            b"SHELL\0" as *const u8 as *const libc::c_char,
+            current_user.shell,
+            0 as libc::c_int);
+    }
+}
+