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copied!<p>As you've noticed, an expression such as the following is greedy:</p> <pre><code>http:.*\.jpg </code></pre> <p>That means it reads as much input as possible while satisfying the expression.</p> <p>It's the "<code>*</code>" operator that makes it greedy. There's a well-defined regex technique to making this non-greedy… use the "?" modifier after the "<code>*</code>".</p> <pre><code>http:.*?\.jpg </code></pre> <p>Now it will match as little as possible while still satisifying the expression (i.e. it will stop searching at the first occurrence of ".jpg".</p> <p>Of course, if you have a .jpg in the middle of a URL, like:</p> <pre><code>http://mydomain.com/some.jpg-folder/foo.jpg </code></pre> <p>It will not match the full URL.</p> <p>You'll want to define the end of the URL as something that can't be considered part of the URL, such as a space, or a new line, or (if the URL in nested inside parentheses), a closing parenthesis. This can't be solved with just one little regex however if it's included in written language, since URLs are often ambiguous.</p> <p>Take for example:</p> <pre><code>At this page, http://mysite.com/puppy.html, there's a cute little puppy dog. </code></pre> <p>The comma could technically be a part of a URL. You have to deal with a lot of ambiguities like this when looking for URLs in written text, and it's hard not to have bugs due to the ambiguities.</p> <p>EDIT | Here's an example of a regex in PHP that is a quick and dirty solution, being greedy only where needed and <em>trying</em> to deal with the English language:</p> <pre><code><?php $str = "Checkout http://www.foo.com/test?items=bat,ball, for info about bats and balls"; preg_match('/https?:\/\/([a-zA-Z0-9][a-zA-Z0-9-]*)(\.[a-zA-Z0-9-]+)*((\/[^\s]*)(?=[\s\.,;!\?]))\b/i', $str, $matches); var_dump($matches); </code></pre> <p>It outputs:</p> <pre><code>array(5) { [0]=> string(38) "http://www.foo.com/test?items=bat,ball" [1]=> string(3) "www" [2]=> string(4) ".com" [3]=> string(20) "/test?items=bat,ball" [4]=> string(20) "/test?items=bat,ball" } </code></pre> <p>The explanation is in the comments.</p>

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