rust tutorial: nicer error message

src/main.rs

@@ -1,19 +1,22 @@
-#![allow(unused)]
 use clap::Parser;
 
 /// Search for a pattern in a file and display the lines that contain it.
 #[derive(Parser)]
 
 struct Cli {
-    pattern: String,
+    url: String,
     path: std::path::PathBuf,
 }
 
-fn main() {
+fn main() -> Result<(), Box<dyn std::error::Error>> {
     let args = Cli::parse();
-    println!("pattern: {}", args.pattern);
-    println!(
-        "path: {}",
-        args.path.into_os_string().into_string().unwrap()
-    );
+    let result = std::fs::read_to_string(&args.path);
+    let content = match result {
+        Ok(content) => content,
+        Err(error) => {
+            return Err(error.into());
+        }
+    };
+    println!("file content: {}", content);
+    Ok(())
 }