feat: add getting admin to cross, knock out a todo

shell/src/ash.rs

@@ -10,10 +10,12 @@ impl Command for Ash {
     fn execute(&self) {
         loop {
             let path = env::current_dir();
-            print!(
-                "{} $ ", // TODO: display "#" if root
-                path.expect("unknown").display()
-            );
+            let userchar = if boxutils::cross::user::is_admin() {
+                '#'
+            } else {
+                '$'
+            };
+            print!("{} {} ", path.expect("unknown").display(), userchar);
             let _ = io::stdout().flush();
             let mut input = String::new();
             io::stdin().read_line(&mut input).unwrap();

utils/src/cross/mod.rs

@@ -1 +1,2 @@
 pub mod fs;
+pub mod user;

utils/src/cross/user/mod.rs

@@ -0,0 +1,11 @@
+#[cfg(windows)]
+mod win;
+
+#[cfg(windows)]
+pub use win::*;
+
+#[cfg(unix)]
+mod unix;
+
+#[cfg(unix)]
+pub use unix::*;

utils/src/cross/user/unix.rs

@@ -0,0 +1,37 @@
+#![cfg(unix)]
+
+use std::fs;
+use std::process::Command;
+
+/// A safe wrapper for checking if the user is root.
+struct UserPrivileges;
+
+impl UserPrivileges {
+    fn is_root() -> bool {
+        if let Ok(status) = fs::read_to_string("/proc/self/status") {
+            for line in status.lines() {
+                if line.starts_with("Uid:") {
+                    let uid: u32 = line
+                        .split_whitespace()
+                        .nth(1)
+                        .unwrap_or("1")
+                        .parse()
+                        .unwrap_or(1);
+                    return uid == 0;
+                }
+            }
+        }
+
+        // Fallback: Run `id -u`
+        Command::new("id")
+            .arg("-u")
+            .output()
+            .map(|o| o.stdout == b"0\n")
+            .unwrap_or(false)
+    }
+}
+
+/// Safe function to check if the user has root privileges.
+pub fn is_admin() -> bool {
+    UserPrivileges::is_root()
+}

utils/src/cross/user/win.rs

@@ -0,0 +1,83 @@
+#![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;
+
+#[link(name = "advapi32")]
+unsafe extern "system" {
+    fn OpenProcessToken(process: *mut c_void, access: c_ulong, token: *mut *mut c_void) -> i32;
+    fn GetTokenInformation(
+        token_handle: *mut c_void,
+        token_info_class: c_ulong,
+        token_info: *mut c_void,
+        token_info_length: c_ulong,
+        return_length: *mut c_ulong,
+    ) -> i32;
+    fn GetCurrentProcess() -> *mut c_void;
+    fn CloseHandle(handle: *mut c_void) -> i32;
+}
+
+const TOKEN_QUERY: c_ulong = 0x0008;
+const TOKEN_ELEVATION: c_ulong = 20;
+
+#[repr(C)]
+struct TokenElevation {
+    token_is_elevated: c_ulong,
+}
+
+/// A safe wrapper around a Windows access token handle.
+struct AccessToken {
+    handle: *mut c_void,
+}
+
+impl AccessToken {
+    /// Opens the access token for the current process.
+    fn open() -> Option<Self> {
+        let process = unsafe { GetCurrentProcess() };
+        let mut token_handle: *mut c_void = ptr::null_mut();
+
+        let success = unsafe { OpenProcessToken(process, TOKEN_QUERY, &mut token_handle) };
+        if success == 0 {
+            return None;
+        }
+
+        Some(Self { handle: token_handle })
+    }
+
+    /// Checks if the token is elevated (i.e., running as an administrator).
+    fn is_elevated(&self) -> bool {
+        let mut elevation: TokenElevation = unsafe { zeroed() };
+        let mut return_length: c_ulong = 0;
+
+        let success = unsafe {
+            GetTokenInformation(
+                self.handle,
+                TOKEN_ELEVATION,
+                &mut elevation as *mut _ as *mut c_void,
+                size_of::<TokenElevation>() as c_ulong,
+                &mut return_length,
+            )
+        };
+
+        success != 0 && elevation.token_is_elevated != 0
+    }
+}
+
+impl Drop for AccessToken {
+    /// Ensures the token handle is always closed properly.
+    fn drop(&mut self) {
+        unsafe { CloseHandle(self.handle) };
+    }
+}
+
+/// Safe function to check if the user is an administrator.
+pub fn is_admin() -> bool {
+    if let Some(token) = AccessToken::open() {
+        token.is_elevated()
+    } else {
+        false
+    }
+}