coreutils: output proper error for unrecognized options

Author: ChrisDryden

src/bin/coreutils.rs

@@ -127,6 +127,9 @@ fn main() {
                     }
                     usage(&utils, binary_as_util);
                     process::exit(0);
+                } else if util.starts_with('-') {
+                    // Argument looks like an option but wasn't recognized
+                    validation::unrecognized_option(binary_as_util, &util_os);
                 } else {
                     validation::not_found(&util_os);
                 }

src/common/validation.rs

@@ -29,6 +29,16 @@ pub fn not_found(util: &OsStr) -> ! {
     process::exit(1);
 }
 
+/// Prints an "unrecognized option" error and exits
+pub fn unrecognized_option(binary_name: &str, option: &OsStr) -> ! {
+    eprintln!(
+        "{}: unrecognized option '{}'",
+        binary_name,
+        option.to_string_lossy()
+    );
+    process::exit(1);
+}
+
 /// Sets up localization for a utility with proper error handling
 pub fn setup_localization_or_exit(util_name: &str) {
     let util_name = get_canonical_util_name(util_name);