Feat: Use BufReader for better io efficiency.

src/main.rs

@@ -1,4 +1,6 @@
 use clap::Parser;
+use std::fs::File;
+use std::io::{BufRead, BufReader};
 
 // Search for a pattern in a file and display the lines that contain it.
 #[derive(Parser)]
@@ -7,8 +9,19 @@ struct Cli {
     path: std::path::PathBuf,
 }
 
-fn main() {
+fn main() -> std::io::Result<()> {
     let args = Cli::parse();
 
-    println!("pattern: {:?}, path: {:?}", args.pattern, args.path)
+    let f = File::open(&args.path)?;
+    let mut reader = BufReader::new(f);
+    let mut line = String::new();
+
+    while reader.read_line(&mut line)? > 0 {
+        if line.contains(&args.pattern) {
+            println!("{}", line)
+        }
+        line.clear();
+    }
+
+    Ok(())
 }