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)]
@@ -7,14 +9,19 @@ struct Cli {
     path: std::path::PathBuf,
 }
 
-fn main() {
+fn main() -> std::io::Result<()> {
     let args = Cli::parse();
 
-    let content = std::fs::read_to_string(&args.path).expect("Could not read file.");
+    let f = File::open(&args.path)?;
+    let mut reader = BufReader::new(f);
+    let mut line = String::new();
 
-    for line in content.lines() {
+    while reader.read_line(&mut line)? > 0 {
         if line.contains(&args.pattern) {
             println!("{}", line)
         }
+        line.clear();
     }
+
+    Ok(())
 }