sleep: use pause

Signed-off-by: Tamerlan Salkenov <catamana@proton.me>

Author: tsalkenov

Cargo.lock

@@ -22,6 +22,9 @@ clap = { workspace = true }
 uucore = { workspace = true, features = ["parser"] }
 fluent = { workspace = true }
 
+[target.'cfg(unix)'.dependencies]
+nix = { workspace = true }
+
 [[bin]]
 name = "sleep"
 path = "src/main.rs"

src/uu/sleep/Cargo.toml

@@ -70,6 +70,15 @@ fn sleep(args: &[&str]) -> UResult<()> {
     if arg_error {
         return Err(UUsageError::new(1, ""));
     }
+
+    #[cfg(unix)]
+    {
+        if sleep_dur == Duration::MAX {
+            nix::unistd::pause();
+            return Ok(());
+        }
+    }
+
     thread::sleep(sleep_dur);
     Ok(())
 }