fn judge file is compressed.

src/main.rs

@@ -22,13 +22,23 @@ fn unar_file(path: &Path) -> io::Result<()> {
         }
         Err(e) => {
             eprintln!("Failed to execute unar for {:?}: {}", path, e);
-            return Err(e);
         }
     }
 
     Ok(())
 }
 
+fn is_compressed(path: &Path) -> bool {
+    if let Some(ext) = path.extension() {
+        if let Some(ext) = ext.to_str() {
+            let ext = ext.to_lowercase();
+            return ext == "zip" || ext == "rar";
+        }
+    }
+
+    false
+}
+
 fn process_compressed_files(path: &Path) -> io::Result<()> {
     if !path.is_dir() {
         return Err(io::Error::new(io::ErrorKind::Other, "Not a directory"));
@@ -39,12 +49,10 @@ fn process_compressed_files(path: &Path) -> io::Result<()> {
         let entry_path = entry?.path();
         if entry_path.is_dir() {
             process_compressed_files(&entry_path)?;
-        } else if let Some(ext) = entry_path.extension().and_then(|e| e.to_str()) {
-            if ext == "rar" || ext == "zip" {
+        } else if is_compressed(entry_path.as_path()) {
             unar_file(&entry_path).expect("UNAR Error.");
         }
     }
-    }
 
     Ok(())
 }