Read a file

Read a file

Run from the repository or distribution root. Put xen on PATH, or substitute ./bin/xen.

The first command creates or overwrites input.txt in the current directory. Exactly one path is required; a missing file terminates with an error.

Run

printf 'one two\nthree four\n' > input.txt
xen run examples/word_count.xen -- input.txt

Expected output

4

Complete source

word_count.xen

// SPDX-License-Identifier: MIT OR Apache-2.0
use std.env as env;
use std.fs as fs;
use std.io as io;
use std.string as text;

fn count_file(path: String) -> Result<Int, io.IoError> {
    let contents = fs.read(path)?;
    return Result.Ok(text.split_ascii_whitespace(contents).len());
}

fn main() {
    let arguments = env.args();
    if arguments.len() != 1 {
        panic("usage: word_count <path>");
    }
    match count_file(arguments.get(0)) {
        Result.Ok(count) => println(count),
        Result.Err(error) => { panic(io.describe_error(error)); },
    };
}

Download file

Build an executable

xen build examples/word_count.xen -o app

Run the generated executable on a compatible Linux machine.