feat: add get_username to user

coreutils/src/commands/whoami.rs

@@ -1,6 +1,6 @@
 use boxutils::args::ArgParser;
 use boxutils::commands::Command;
-use std::env;
+use boxutils::cross::user;
 
 pub struct WhoAmI;
 
@@ -13,9 +13,7 @@ impl Command for WhoAmI {
             return;
         }
 
-        let username = env::var("USER") // Unix
-            .or_else(|_| env::var("USERNAME")) // Windows
-            .unwrap_or_else(|_| "unknown".to_string());
+        let username = user::get_username().unwrap_or_else(|| "unknown".to_string());
 
         println!("{}", username);
     }

utils/src/cross/user/unix.rs

@@ -35,3 +35,7 @@ impl UserPrivileges {
 pub fn is_admin() -> bool {
     UserPrivileges::is_root()
 }
+
+pub fn get_username() -> Option<String> {
+    std::env::var("USER").ok()
+}

utils/src/cross/user/win.rs

@@ -1,10 +1,10 @@
 #![allow(dead_code)]
 #![cfg(windows)]
 
-use std::ptr;
 use std::ffi::c_void;
 use std::mem::{size_of, zeroed};
 use std::os::raw::c_ulong;
+use std::ptr;
 
 #[link(name = "advapi32")]
 unsafe extern "system" {
@@ -44,7 +44,9 @@ impl AccessToken {
             return None;
         }
 
-        Some(Self { handle: token_handle })
+        Some(Self {
+            handle: token_handle,
+        })
     }
 
     /// Checks if the token is elevated (i.e., running as an administrator).
@@ -80,4 +82,8 @@ pub fn is_admin() -> bool {
     } else {
         false
     }
-}
+}
+
+pub fn get_username() -> Option<String> {
+    std::env::var("USERNAME").ok()
+}