feat: add the whoami command

coreutils/src/commands/mod.rs

@@ -17,3 +17,4 @@ command!(test::Test);
 command!(yes::Yes);
 command!(pwd::Pwd);
 command!(sleep::Sleep);
+command!(whoami::WhoAmI);

coreutils/src/commands/whoami.rs

@@ -0,0 +1,22 @@
+use boxutils::args::ArgParser;
+use boxutils::commands::Command;
+use std::env;
+
+pub struct WhoAmI;
+
+impl Command for WhoAmI {
+    fn execute(&self) {
+        let args = ArgParser::builder().add_flag("--help").parse_args("whoami");
+
+        if args.get_flag("--help") {
+            println!("Usage: whoami");
+            return;
+        }
+
+        let username = env::var("USER") // Unix
+            .or_else(|_| env::var("USERNAME")) // Windows
+            .unwrap_or_else(|_| "unknown".to_string());
+
+        println!("{}", username);
+    }
+}

src/registry.rs

@@ -27,6 +27,7 @@ pub fn get_registry() -> CommandRegistry {
         "yes" => coreutils::commands::Yes,
         "pwd" => coreutils::commands::Pwd,
         "sleep" => coreutils::commands::Sleep,
+        "whoami" => coreutils::commands::WhoAmI,
         "box" => Boxcmd
     });