trpl-zh-cn/listings/ch12-an-io-project/listing-12-12/src/main.rs
2022-02-06 16:43:51 +08:00

52 lines
1001 B
Rust
Executable File

use std::env;
use std::fs;
use std::process;
// ANCHOR: here
use std::error::Error;
// --snip--
// ANCHOR_END: here
fn main() {
let args: Vec<String> = env::args().collect();
let config = Config::new(&args).unwrap_or_else(|err| {
println!("Problem parsing arguments: {}", err);
process::exit(1);
});
println!("Searching for {}", config.query);
println!("In file {}", config.filename);
run(config);
}
// ANCHOR: here
fn run(config: Config) -> Result<(), Box<dyn Error>> {
let contents = fs::read_to_string(config.filename)?;
println!("With text:\n{}", contents);
Ok(())
}
// ANCHOR_END: here
struct Config {
query: String,
filename: String,
}
impl Config {
fn new(args: &[String]) -> Result<Config, &'static str> {
if args.len() < 3 {
return Err("not enough arguments");
}
let query = args[1].clone();
let filename = args[2].clone();
Ok(Config { query, filename })
}
}