试试这个:

function isUrl(s) {
    if (!isUrl.rx_url) {
        // taken from https://gist.github.com/dperini/729294
        isUrl.rx_url=/^(?:(?:https?|ftp):\/\/)?(?:\S+(?::\S*)?@)?(?:(?!(?:10|127)(?:\.\d{1,3}){3})(?!(?:169\.254|192\.168)(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[a-z\u00a1-\uffff]{2,}))\.?)(?::\d{2,5})?(?:[/?#]\S*)?$/i;
        // valid prefixes
        isUrl.prefixes=['http:\/\/', 'https:\/\/', 'ftp:\/\/', 'www.'];
        // taken from https://w3techs.com/technologies/overview/top_level_domain/all
        isUrl.domains=['com','ru','net','org','de','jp','uk','br','pl','in','it','fr','au','info','nl','ir','cn','es','cz','kr','ua','ca','eu','biz','za','gr','co','ro','se','tw','mx','vn','tr','ch','hu','at','be','dk','tv','me','ar','no','us','sk','xyz','fi','id','cl','by','nz','il','ie','pt','kz','io','my','lt','hk','cc','sg','edu','pk','su','bg','th','top','lv','hr','pe','club','rs','ae','az','si','ph','pro','ng','tk','ee','asia','mobi'];
    }

    if (!isUrl.rx_url.test(s)) return false;
    for (let i=0; i<isUrl.prefixes.length; i++) if (s.startsWith(isUrl.prefixes[i])) return true;
    for (let i=0; i<isUrl.domains.length; i++) if (s.endsWith('.'+isUrl.domains[i]) || s.includes('.'+isUrl.domains[i]+'\/') ||s.includes('.'+isUrl.domains[i]+'?')) return true;
    return false;
}

function isEmail(s) {
    if (!isEmail.rx_email) {
        // taken from http://stackoverflow.com/a/16016476/460084
        var sQtext = '[^\\x0d\\x22\\x5c\\x80-\\xff]';
        var sDtext = '[^\\x0d\\x5b-\\x5d\\x80-\\xff]';
        var sAtom = '[^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+';
        var sQuotedPair = '\\x5c[\\x00-\\x7f]';
        var sDomainLiteral = '\\x5b(' + sDtext + '|' + sQuotedPair + ')*\\x5d';
        var sQuotedString = '\\x22(' + sQtext + '|' + sQuotedPair + ')*\\x22';
        var sDomain_ref = sAtom;
        var sSubDomain = '(' + sDomain_ref + '|' + sDomainLiteral + ')';
        var sWord = '(' + sAtom + '|' + sQuotedString + ')';
        var sDomain = sSubDomain + '(\\x2e' + sSubDomain + ')*';
        var sLocalPart = sWord + '(\\x2e' + sWord + ')*';
        var sAddrSpec = sLocalPart + '\\x40' + sDomain; // complete RFC822 email address spec
        var sValidEmail = '^' + sAddrSpec + '$'; // as whole string

        isEmail.rx_email = new RegExp(sValidEmail);
    }

    return isEmail.rx_email.test(s);
}

还将识别url，如google.com, http://www.google.bla, http://google.bla, www.google.bla但不是google.bla

功能可以进一步改善渲染图像以及:

function renderHTML(text) { 
    var rawText = strip(text)
    var urlRegex =/(\b(https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])/ig;   

    return rawText.replace(urlRegex, function(url) {   

    if ( ( url.indexOf(".jpg") > 0 ) || ( url.indexOf(".png") > 0 ) || ( url.indexOf(".gif") > 0 ) ) {
            return '<img src="' + url + '">' + '<br/>'
        } else {
            return '<a href="' + url + '">' + url + '</a>' + '<br/>'
        }
    }) 
} 

或者对于链接到完整大小图像的缩略图:

return '<a href="' + url + '"><img style="width: 100px; border: 0px; -moz-border-radius: 5px; border-radius: 5px;" src="' + url + '">' + '</a>' + '<br/>'

下面是strip()函数，它通过删除任何现有html对文本字符串进行预处理以实现一致性。

function strip(html) 
    {  
        var tmp = document.createElement("DIV"); 
        tmp.innerHTML = html; 
        var urlRegex =/(\b(https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])/ig;   
        return tmp.innerText.replace(urlRegex, function(url) {     
        return '\n' + url 
    })
} 

如果您想检测带有http:// OR而不带有http://或ftp或其他可能的情况(如删除末尾的标点符号)的链接，请查看这段代码。

https://jsfiddle.net/AndrewKang/xtfjn8g3/

使用它的一个简单方法是使用NPM

npm install --save url-knife

试试这个:

function isUrl(s) {
    if (!isUrl.rx_url) {
        // taken from https://gist.github.com/dperini/729294
        isUrl.rx_url=/^(?:(?:https?|ftp):\/\/)?(?:\S+(?::\S*)?@)?(?:(?!(?:10|127)(?:\.\d{1,3}){3})(?!(?:169\.254|192\.168)(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[a-z\u00a1-\uffff]{2,}))\.?)(?::\d{2,5})?(?:[/?#]\S*)?$/i;
        // valid prefixes
        isUrl.prefixes=['http:\/\/', 'https:\/\/', 'ftp:\/\/', 'www.'];
        // taken from https://w3techs.com/technologies/overview/top_level_domain/all
        isUrl.domains=['com','ru','net','org','de','jp','uk','br','pl','in','it','fr','au','info','nl','ir','cn','es','cz','kr','ua','ca','eu','biz','za','gr','co','ro','se','tw','mx','vn','tr','ch','hu','at','be','dk','tv','me','ar','no','us','sk','xyz','fi','id','cl','by','nz','il','ie','pt','kz','io','my','lt','hk','cc','sg','edu','pk','su','bg','th','top','lv','hr','pe','club','rs','ae','az','si','ph','pro','ng','tk','ee','asia','mobi'];
    }

    if (!isUrl.rx_url.test(s)) return false;
    for (let i=0; i<isUrl.prefixes.length; i++) if (s.startsWith(isUrl.prefixes[i])) return true;
    for (let i=0; i<isUrl.domains.length; i++) if (s.endsWith('.'+isUrl.domains[i]) || s.includes('.'+isUrl.domains[i]+'\/') ||s.includes('.'+isUrl.domains[i]+'?')) return true;
    return false;
}

function isEmail(s) {
    if (!isEmail.rx_email) {
        // taken from http://stackoverflow.com/a/16016476/460084
        var sQtext = '[^\\x0d\\x22\\x5c\\x80-\\xff]';
        var sDtext = '[^\\x0d\\x5b-\\x5d\\x80-\\xff]';
        var sAtom = '[^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+';
        var sQuotedPair = '\\x5c[\\x00-\\x7f]';
        var sDomainLiteral = '\\x5b(' + sDtext + '|' + sQuotedPair + ')*\\x5d';
        var sQuotedString = '\\x22(' + sQtext + '|' + sQuotedPair + ')*\\x22';
        var sDomain_ref = sAtom;
        var sSubDomain = '(' + sDomain_ref + '|' + sDomainLiteral + ')';
        var sWord = '(' + sAtom + '|' + sQuotedString + ')';
        var sDomain = sSubDomain + '(\\x2e' + sSubDomain + ')*';
        var sLocalPart = sWord + '(\\x2e' + sWord + ')*';
        var sAddrSpec = sLocalPart + '\\x40' + sDomain; // complete RFC822 email address spec
        var sValidEmail = '^' + sAddrSpec + '$'; // as whole string

        isEmail.rx_email = new RegExp(sValidEmail);
    }

    return isEmail.rx_email.test(s);
}

还将识别url，如google.com, http://www.google.bla, http://google.bla, www.google.bla但不是google.bla

首先，你需要一个匹配url的正则表达式。这很难做到。看这里，这里和这里:

...almost anything is a valid URL. There are some punctuation rules for splitting it up. Absent any punctuation, you still have a valid URL. Check the RFC carefully and see if you can construct an "invalid" URL. The rules are very flexible. For example ::::: is a valid URL. The path is ":::::". A pretty stupid filename, but a valid filename. Also, ///// is a valid URL. The netloc ("hostname") is "". The path is "///". Again, stupid. Also valid. This URL normalizes to "///" which is the equivalent. Something like "bad://///worse/////" is perfectly valid. Dumb but valid.

无论如何，这个答案并不是为了给您最好的正则表达式，而是为了证明如何使用JavaScript在文本中进行字符串包装。

所以让我们用这一个:/ (https ?: \ / \ / ^ \ [s] +) / g

同样，这是一个糟糕的正则表达式。它会有很多假阳性。但是对于这个例子来说已经足够好了。

函数urlify(text) { var urlRegex = /(https?:\/\/[^\s]+)/g; 返回文本。替换(urlRegex，函数(url) { 返回'<a href="' + url + '">' + url + '</a>'; }) //或者 //返回文本。替换(urlRegex， '<a href="$1">$1</a>') ｝ var text = '在http://www.example.com和http://stackoverflow.com上找到我'; Var HTML = urlify(文本); console.log (html)

// html now looks like:
// "Find me at <a href="http://www.example.com">http://www.example.com</a> and also at <a href="http://stackoverflow.com">http://stackoverflow.com</a>"

所以总的来说:

$$('#pad dl dd').each(function(element) {
    element.innerHTML = urlify(element.innerHTML);
});

NPM的这个库看起来很全面https://www.npmjs.com/package/linkifyjs

Linkify是一个小而全面的JavaScript插件，用于查找纯文本的url并将其转换为HTML链接。它适用于所有有效的url和电子邮件地址。