$ cargo run the poem.txt Compiling minigrep v0.1.0 (file:///projects/minigrep) warning: unused `Result` that must be used --> src/main.rs:19:5 | 19 | run(config); | ^^^^^^^^^^^^ | = note: `#[warn(unused_must_use)]` on by default = note: this `Result` may be an `Err` variant, which should be handled warning: `minigrep` (bin "minigrep") generated 1 warning Finished dev [unoptimized + debuginfo] target(s) in 0.71s Running `target/debug/minigrep the poem.txt` Searching for the In file poem.txt With text: I'm nobody! Who are you? Are you nobody, too? Then there's a pair of us - don't tell! They'd banish us, you know. How dreary to be somebody! How public, like a frog To tell your name the livelong day To an admiring bog!