Add whoami applet

src/cmd/mod.rs

@@ -32,13 +32,14 @@ pub mod shitbox;
 pub mod sleep;
 mod sync;
 pub mod r#true;
+pub mod whoami;
 pub mod yes;
 
 pub use {
     self::hostname::Hostname, base32::Base32, base64::Base64, basename::Basename,
     bootstrap::Bootstrap, dirname::Dirname, echo::Echo, factor::Factor, fold::Fold, head::Head,
     mountpoint::Mountpoint, nologin::Nologin, nproc::Nproc, r#false::False, r#true::True, rev::Rev,
-    shitbox::Shitbox, sleep::Sleep, yes::Yes,
+    shitbox::Shitbox, sleep::Sleep, whoami::Whoami, yes::Yes,
 };
 
 pub trait Cmd: fmt::Debug + Sync {
@@ -67,12 +68,13 @@ pub fn get(name: &str) -> Option<Box<dyn Cmd>> {
         "shitbox" => Some(Box::new(Shitbox::default())),
         "sleep" => Some(Box::new(Sleep::default())),
         "true" => Some(Box::new(True::default())),
+        "whoami" => Some(Box::new(Whoami::default())),
         "yes" => Some(Box::new(Yes::default())),
         _ => None,
     }
 }
 
-pub static COMMANDS: [&'static str; 19] = [
+pub static COMMANDS: [&'static str; 20] = [
     "base32",
     "base64",
     "basename",
@@ -91,5 +93,6 @@ pub static COMMANDS: [&'static str; 19] = [
     "sleep",
     "shitbox",
     "true",
+    "whoami",
     "yes",
 ];

src/cmd/whoami/mod.rs

@@ -0,0 +1,36 @@
+use std::ffi::CStr;
+
+use {
+    clap::Command,
+    libc::{geteuid, getpwuid},
+    super::Cmd,
+};
+
+#[derive(Debug, Default)]
+pub struct Whoami;
+
+impl Cmd for Whoami {
+    fn name(&self) -> &str {
+        "whoami"
+    }
+
+    fn cli(&self) -> clap::Command {
+        Command::new("whoami")
+            .about("print effective user name")
+            .author("Nathan Fisher")
+    }
+
+    fn run(&self, _matches: Option<&clap::ArgMatches>) -> Result<(), Box<dyn std::error::Error>> {
+        let pwnam = unsafe {
+            let pw = *getpwuid(geteuid());
+            CStr::from_ptr((pw).pw_name)
+        };
+        let pwnam = pwnam.to_str()?;
+        println!("{pwnam}");
+        Ok(())
+    }
+
+    fn path(&self) -> Option<crate::Path> {
+        Some(crate::Path::UsrBin)
+    }
+}