feat: new host_name() API (#550)

yazi-plugin/src/utils/user.rs

@@ -6,8 +6,9 @@ impl Utils {
 	#[cfg(unix)]
 	pub(super) fn user(lua: &Lua, ya: &Table) -> mlua::Result<()> {
 		use uzers::{Groups, Users};
+		use yazi_shared::hostname;
 
-		use crate::utils::USERS_CACHE;
+		use crate::utils::{HOSTNAME_CACHE, USERS_CACHE};
 
 		ya.set("uid", lua.create_function(|_, ()| Ok(USERS_CACHE.get_current_uid()))?)?;
 
@@ -33,6 +34,17 @@ impl Utils {
 			})?,
 		)?;
 
+		ya.set(
+			"host_name",
+			lua.create_function(|lua, ()| {
+				HOSTNAME_CACHE
+					.get_or_init(|| hostname().ok())
+					.as_ref()
+					.map(|s| lua.create_string(s))
+					.transpose()
+			})?,
+		)?;
+
 		Ok(())
 	}
 

yazi-plugin/src/utils/utils.rs

@@ -3,6 +3,8 @@ use mlua::{Lua, Table};
 #[cfg(unix)]
 pub(super) static USERS_CACHE: yazi_shared::RoCell<uzers::UsersCache> = yazi_shared::RoCell::new();
 
+pub(super) static HOSTNAME_CACHE: std::sync::OnceLock<Option<String>> = std::sync::OnceLock::new();
+
 pub(super) struct Utils;
 
 pub fn init() {

yazi-shared/src/lib.rs

@@ -12,6 +12,7 @@ mod layer;
 mod mime;
 mod natsort;
 mod number;
+mod os;
 mod ro_cell;
 pub mod term;
 mod throttle;
@@ -27,6 +28,7 @@ pub use layer::*;
 pub use mime::*;
 pub use natsort::*;
 pub use number::*;
+pub use os::*;
 pub use ro_cell::*;
 pub use throttle::*;
 pub use time::*;

yazi-shared/src/os.rs

@@ -0,0 +1,19 @@
+#[cfg(unix)]
+pub fn hostname() -> Result<String, std::io::Error> {
+	use std::io::{Error, ErrorKind};
+
+	use libc::{gethostname, strlen};
+
+	let mut s = [0; 256];
+	let len = unsafe {
+		if gethostname(s.as_mut_ptr() as *mut _, 255) == -1 {
+			return Err(std::io::Error::last_os_error());
+		}
+
+		strlen(s.as_ptr() as *const _)
+	};
+
+	std::str::from_utf8(&s[..len])
+		.map_err(|_| Error::new(ErrorKind::Other, "invalid hostname"))
+		.map(|s| s.to_owned())
+}