2022-03-03 18:32:29 +00:00
|
|
|
// Note: this requires the `cargo` feature
|
|
|
|
|
2022-02-08 04:50:39 +00:00
|
|
|
use std::ops::RangeInclusive;
|
|
|
|
|
2022-03-14 14:31:40 +00:00
|
|
|
use clap::{arg, command};
|
2021-11-30 18:30:19 +00:00
|
|
|
|
|
|
|
fn main() {
|
2022-02-15 14:33:38 +00:00
|
|
|
let matches = command!()
|
2022-03-14 14:31:40 +00:00
|
|
|
.arg(
|
|
|
|
arg!(<PORT>)
|
|
|
|
.help("Network port to use")
|
|
|
|
.validator(port_in_range),
|
|
|
|
)
|
2021-11-30 18:30:19 +00:00
|
|
|
.get_matches();
|
|
|
|
|
|
|
|
// Note, it's safe to call unwrap() because the arg is required
|
|
|
|
let port: usize = matches
|
|
|
|
.value_of_t("PORT")
|
2021-12-13 10:41:12 +00:00
|
|
|
.expect("'PORT' is required and parsing will fail if its missing");
|
2021-11-30 18:30:19 +00:00
|
|
|
println!("PORT = {}", port);
|
|
|
|
}
|
2022-03-14 14:31:40 +00:00
|
|
|
|
|
|
|
const PORT_RANGE: RangeInclusive<usize> = 1..=65535;
|
|
|
|
|
|
|
|
fn port_in_range(s: &str) -> Result<(), String> {
|
|
|
|
let port: usize = s
|
|
|
|
.parse()
|
|
|
|
.map_err(|_| format!("`{}` isn't a port number", s))?;
|
|
|
|
if PORT_RANGE.contains(&port) {
|
|
|
|
Ok(())
|
|
|
|
} else {
|
|
|
|
Err(format!(
|
|
|
|
"Port not in range {}-{}",
|
|
|
|
PORT_RANGE.start(),
|
|
|
|
PORT_RANGE.end()
|
|
|
|
))
|
|
|
|
}
|
|
|
|
}
|