Reading command line arguments

Rust:
Reading command line arguments

How to:

Here’s the simplest way to grab arguments:

use std::env;

fn main() {
    let args: Vec<String> = env::args().collect();
    println!("{:?}", args);
}

Run it with cargo run arg1 arg2. You’ll see:

["path/to/executable", "arg1", "arg2"]

A tidier option with iterators:

use std::env;

fn main() {
    for arg in env::args().skip(1) {
        println!("{}", arg);
    }
}

Now try cargo run cool stuff:

cool
stuff

Historically, command line arguments are a throwback to the days when GUIs weren’t widespread. Now, they’re great for scripts, servers, or tools.

Rust’s std::env::args uses an iterator, which is memory efficient and lazy. It handles Unicode too. There’s also args_os for raw OS strings.

For complex parsing, crates like clap or structopt come in handy. They parse flags, options, and subcommands.