function randomPost() {
    fetch('/sitemap.xml').then(res => res.text()).then(str => (new window.DOMParser()).parseFromString(str, "text/xml")).then(data => {
        let ls = data.querySelectorAll('url loc');
        let locationHref,locSplit;
        do {
            locationHref = ls[Math.floor(Math.random() * ls.length)].innerHTML
            locSplit = locationHref.split('/')[3] || ''
        } while (locSplit !== 'posts');
        //若所有文章都如 https://…….com/posts/2022/07/…… 格式，主域名后字符是 posts，则循环条件改为：
        //while (locSplit !== 'posts');
        location.href = locationHref
    })
}