refactor: refactor

src/main.rs

@@ -1,4 +1,6 @@
 use clap::Clap;
+use std::fs::OpenOptions;
+use std::io::prelude::*;
 use std::io::{self, Read};
 
 use copyrat::{run, Opt};
@@ -13,5 +15,22 @@ fn main() {
     let mut buffer = String::new();
     handle.read_to_string(&mut buffer).unwrap();
 
-    run(buffer, opt);
+    // Execute copyrat over the buffer (will take control over stdout).
+    // This returns the selected matches.
+    let output: String = run(buffer, &opt);
+
+    // Write output to a target_path if provided, else print to original stdout.
+    match opt.target_path {
+        None => println!("{}", output),
+        Some(target) => {
+            let mut file = OpenOptions::new()
+                .create(true)
+                .truncate(true)
+                .write(true)
+                .open(target)
+                .expect("Unable to open the target file");
+
+            file.write(output.as_bytes()).unwrap();
+        }
+    }
 }