expr: exit 3 on write failure for --help/--version

Author: sylvestre

src/uu/expr/src/expr.rs

@@ -109,9 +109,20 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         .collect::<Result<Vec<_>, _>>()?;
 
     if args.len() == 1 && args[0] == b"--help" {
-        uu_app().print_help()?;
+        if uu_app().print_help().is_err() {
+            std::process::exit(3);
+        }
     } else if args.len() == 1 && args[0] == b"--version" {
-        writeln!(stdout(), "expr {}", uucore::crate_version!())?;
+        if writeln!(
+            stdout(),
+            "{} {}",
+            uucore::util_name(),
+            uucore::crate_version!()
+        )
+        .is_err()
+        {
+            std::process::exit(3);
+        }
     } else {
         // The first argument may be "--" and should be be ignored.
         let args = if !args.is_empty() && args[0] == b"--" {