Read a file as stream

The File.read method is used to read a file in stream mode. The first argument accpets a std.io.Bytes as a buffer to store the read data.

You must special each read operation to handle the buffer size and the read data. For example 1024 bytes buffer size, and read until the end of the file.

Every call read method it will return the actual read bytes length, if it's 0, it means the end of the file. So you can use it to break the loop.

Navi Code

use std.fs.File;
use std.io.Bytes;

fn main() throws {
    let file = try File.open("path/to/file.txt");

    loop {
        let chunk = Bytes.new(len: 1024);
        // Read 1024 bytes to chunk, if the end of the file, it will return 0
        if (try file.read(chunk) == 0) {
            break;
        }

        // Do something with buf
        print(chunk.to_string());
    }
}