浅析JavaScript如何使用User-Agent精准获取浏览器与操作系统信息

/**
 * 获取系统信息（增强版）
 * 返回对象包含：
 *   browserName, browserVersion  - 浏览器名称和版本
 *   name, version                - 操作系统名称和版本
 */
function getSysInfo() {
    const ua = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) EdgiOS/144 Version/16.0 Safari/605.1.15".toLowerCase();
    const sys = {};
    // ---------- 浏览器解析 ----------
    // 浏览器标识列表（按优先级排列）
    const browserPatterns = [
        { name: 'firefox',      pattern: /firefox\/([\d.]+)/ },
        { name: 'edg',          pattern: /edg\/([\d.]+)/ },          // Chromium Edge
        { name: 'edge',         pattern: /edge\/([\d.]+)/ },         // Edge Legacy
        { name: 'chrome',       pattern: /chrome\/([\d.]+)/ },       // 包括 HeadlessChrome（仍含 chrome 标识）
        { name: 'safari',       pattern: /version\/([\d.]+).*safari/ }, // Safari 版本通常在 version 字段
        { name: 'opera',        pattern: /(?:opera|opr)\/([\d.]+)/ },
        { name: 'msie',         pattern: /msie ([\d.]+)/ },
        { name: 'trident',      pattern: /trident.*rv:([\d.]+)/ }    // IE11
    ];
    for (const { name, pattern } of browserPatterns) {
        const match = ua.match(pattern);
        if (match) {
            sys.browserName = name;
            sys.browserVersion = match[1];
            break;
        }
    }
    // 未匹配到任何浏览器
    if (!sys.browserName) {
        sys.browserName = 'unknown';
        sys.browserVersion = 'unknown';
    }
    // ---------- 操作系统解析 ----------
    // 操作系统模式列表（按优先级）
    const osPatterns = [
        // Windows
        { name: 'Windows', versionPattern: /windows nt ([\d.]+)/, versionTransform: (v) => v },
        // Mac OS X
        { name: 'Mac OS X', versionPattern: /mac os x ([\d_]+)/, versionTransform: (v) => v.replace(/_/g, '.') },
        // iOS (iPhone/iPad/iPod)
        { name: 'iOS', versionPattern: /(?:iphone|ipad|ipod).*?os ([\d_]+)/, versionTransform: (v) => v.replace(/_/g, '.') },
        // Android
        { name: 'Android', versionPattern: /android ([\d.]+)/, versionTransform: (v) => v },
        // Linux
        { name: 'Linux', versionPattern: /linux/, versionTransform: () => null }, // Linux 通常无版本号
        // 其他 Unix-like 系统（如 FreeBSD）
        { name: 'Unix', versionPattern: /(?:freebsd|openbsd|sunos)/, versionTransform: () => null }
    ];
    let osFound = false;
    for (const { name, versionPattern, versionTransform } of osPatterns) {
        const match = ua.match(versionPattern);
        if (match) {
            sys.name = name;
            sys.version = match[1] ? versionTransform(match[1]) : 'unknown';
            osFound = true;
            break;
        }
    }
    // 若未匹配到已知操作系统，则回退到原有的移动设备检测（保留原逻辑）
    if (!osFound) {
        // 原移动检测逻辑（稍作简化，保持兼容）
        const mobileReg = /(mobile|android|ucbrowser|ucweb|tiantian|avantgo|bada\/|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|iphone|ipod|ipad|iris|kindle|lge |maemo|midp|mmp|netfront|opera mobi|opera mini|palm os|palm|phone|pixi\/|pre\/|plucker|pocket|psp|series40|series60|symbian|treo|up\.browser|up\.link|vodafone|wap|windows ce|windows phone|xda|xiino|windows nt|windows).*?([\d.]+)/;
        const m = ua.match(mobileReg);
        if (m) {
            sys.name = m[1];
            sys.version = m[2];
        } else {
            // 尝试前4字符匹配（原逻辑）
            const typeReg = /1207|6310|6590|3gso|4thp|50[1-6]i|770s|802s|a wa|abac|acer|acoo|acs\-|aiko|airn|alav|alca|alco|amoi|anex|anny|anyw|aptu|arch|argo|aste|asus|attw|audi|au\-m|aur |aus |avan|beck|bell|benq|bilb|bird|blac|blaz|brew|brvw|bumb|bw\-n|bw\-u|c55\/|capi|ccwa|cdm\-|cell|chtm|cldc|cmd\-|comp|cond|craw|dait|dall|dang|dbte|dc\-s|devi|dica|dmob|doco|dopo|ds12|ds\-d|el49|elai|eml2|emul|eric|erk0|esl8|ez[4-7]0|ezos|ezwa|ezze|fetc|fly\-|fly_|g1 u|g560|gene|gf\-5|g\-mo|go\.w|good|grad|grun|haie|hcit|hd\-m|hd\-p|hd\-t|hei\-|hipt|hita|hp i|hpip|hs\-c|htc\-|htc |htc_|htca|htcg|htcp|htcs|htct|http|huaw|hutc|i\-20|i\-go|i\-ma|i230|iac |iac\-|iac\/|ibro|idea|ig01|ikom|im1k|inno|ipaq|iris|jata|java|jbro|jemu|jigs|kddi|keji|kgt |kgt\/|klon|kpt |kwc\-|kyoc|kyok|leno|lexi|lg g|lg\/k|lg\/l|lg\/u|lg50|lg54|lg\-[a-w]|libw|lynx|m1\-w|m3ga|m50\/|mate|maui|maxo|mc01|mc21|mcca|m\-cr|merc|meri|mio8|mioa|mits|mmef|mo01|mo02|mobi|mode|modo|mot\-|mot |moto|motv|mozz|mt50|mtp1|mtv |mwbp|mywa|n10[0-2]|n20[2-3]|n300|n302|n500|n502|n505|n700|n701|n710|nec\-|nem\-|neon|netf|newf|newg|newt|nok6|noki|nzph|o2im|opti|opwv|oran|owg1|p800|pana|pand|pant|pdxg|pg13|pg\-[1-8]|pg\-c|phil|pire|play|pluc|pn\-2|pock|port|pose|prox|psio|pt\-g|qa\-a|qc07|qc12|qc21|qc32|qc60|qc\-[2-7]|i\-|qtek|r380|r600|raks|rim9|rove|rozo|s55\/|sage|sama|samm|sams|sany|sava|sc01|sch\-|scoo|scp\-|sdk\/|sec\-|sec0|sec1|se47|semc|send|seri|sgh\-|shar|sie\-|siem|sk\-0|sl45|slid|smal|smar|smb3|smit|smt5|soft|sony|sp01|sph\-|spv\-|spv |sy01|symb|t218|t250|t600|t610|t618|tagt|talk|tcl\-|tdg\-|teli|telm|tim\-|t\-mo|topl|tosh|ts70|tsm\-|tsm3|tsm5|tx\-9|up\.b|upg1|upsi|utst|v400|v750|veri|virg|vite|vk40|vk5[0-3]|vk\-v|vm40|voda|vulc|vx52|vx53|vx60|vx61|vx70|vx80|vx81|vx83|vx85|vx98|w3c\-|w3c |webc|whit|wig |winc|winw|wmlb|wonu|x700|yas\-|your|zeto|zte\-/;
            const m2 = ua.substr(0, 4).match(typeReg);
            if (m2) {
                sys.name = "mobile[" + m2[0] + "]";
            } else {
                sys.name = 'unknown';
            }
            sys.version = 'unknown';
        }
    }
    return sys;
}