ext-uv/examples/fs.php

<?php
uv_fs_open(uv_default_loop(),__FILE__, UV::O_RDONLY, 0, function($r){
    uv_fs_read(uv_default_loop(),$r,function($stream, $nread, $data) {
        if ($nread <= 0) {
            if ($nread < 0) {
                throw new Exception("read error");
            }

            uv_fs_close(uv_default_loop(), $stream, function(){
            });
        } else {
            echo $data;
        }
    });
});

uv_run();