通过UserAgent判读客户端的浏览器信息

//Windows NT 6.2 Win8//Windows NT 6.1 Win7//Windows XP//Windows RT Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; ARM; Trident/6.0)//"Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0)"//"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/536.27.1 (KHTML, like Gecko) Version/5.1.2 Safari/534.52.7"//"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.66 Safari/537.36"//"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:22.0) Gecko/20100101 Firefox/22.0"//"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.57 Safari/537.36"//"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8) AppleWebKit/536.25 (KHTML, like Gecko) Version/6.0 Safari/536.25"function parser(userAgent) {    var start = userAgent.indexOf("(");    userAgent = userAgent.substring(start,userAgent.length);    var os = "Windows";    var bit = "32位";    var brower = "";    if(userAgent.indexOf("Windows NT 6.2")!=-1){        os = "Win8";        if(userAgent.indexOf("ARM;")!=-1){            os = "WinRT";        }    }else if(userAgent.indexOf("Windows NT 6.1")!=-1){        os = "Win7";    }else if(userAgent.indexOf("Windows XP")!=-1){        os = "WinXP";    }else if(userAgent.indexOf("Linux")!=-1){        os = "Linux";    }else if(userAgent.indexOf("Mac")!=-1){        os = "Mac";    }    if(userAgent.indexOf("WOW64")!=-1||userAgent.indexOf("_64")!=-1||userAgent.indexOf("X64")!=-1||userAgent.indexOf("x64")!=-1){        bit = "64位";    }    if(userAgent.indexOf("MSIE")!=-1){        brower = "IE";        var start = userAgent.indexOf("MSIE");        var end = userAgent.indexOf(";",start);        brower = brower+ userAgent.substring(start+5,end);    }else if(userAgent.indexOf("Firefox")!=-1){        brower = "Firefox";        var start = userAgent.indexOf("Firefox/");        brower = brower + userAgent.substring(start+"Firefox".length+1,userAgent.length);    }else if(userAgent.indexOf("Chrome")!=-1){        brower = "Chrome";        var start = userAgent.indexOf("Chrome/");        var end = userAgent.indexOf(".",start);        end = userAgent.indexOf(".",end+1);        brower = brower + userAgent.substring(start+"Chrome".length+1,end);    }else if(userAgent.indexOf("Safari")!=-1){        //Version/5.1.2        brower = "Safari";        var start = userAgent.indexOf("Version/");        var end = userAgent.indexOf(" ",start);        brower = brower + userAgent.substring(start+"Version".length+1,end);    }    return os+"_"+bit+"_"+brower+userAgent;}