正则表达式有条件地用超链接替换Twitter主题标签

I'm writing a small PHP script to grab the latest half dozen Twitter status updates from a user feed and format them for display on a webpage. As part of this I need a regex replace to rewrite hashtags as hyperlinks to search.twitter.com. Initially I tried to use:<?php$strTweet = preg_replace('/(^|\s)#(\w+)/', '\1#<a href="http://search.twitter.com/search?q=%23\2">\2</a>', $strTweet);?>(taken from https://gist.github.com/445729)In the course of testing I discovered that #test is converted into a link on the Twitter website, however #123 is not. After a bit of checking on the internet and playing around with various tags I came to the conclusion that a hashtag must contain alphabetic characters or an underscore in it somewhere to constitute a link; tags with only numeric characters are ignored (presumably to stop things like "Good presentation Bob, slide #3 was my favourite!" from being linked). This makes the above code incorrect, as it will happily convert #123 into a link.I've not done much regex in a while, so in my rustyness I came up with the following PHP solution:<?php$test = 'This is a test tweet to see if #123 and #4 are not encoded but #test, #l33t and #8oo8s are.';// Get all hashtags out into an arrayif (preg_match_all('/(^|\s)(#\w+)/', $test, $arrHashtags) > 0) { foreach ($arrHashtags[2] as $strHashtag) { // Check each tag to see if there are letters or an underscore in there somewhere if (preg_match('/#\d*[a-z_]+/i', $strHashtag)) { $test = str_replace($strHashtag, '<a href="http://search.twitter.com/search?q=%23'.substr($strHashtag, 1).'">'.$strHashtag.'</a>', $test); } }}echo $test;?>It works; but it seems fairly long-winded for what it does. My question is, is there a single preg_replace similar to the one I got from gist.github that will conditionally rewrite hashtags into hyperlinks ONLY if they DO NOT contain just numbers? 解决方案 (^|\s)#(\w*[a-zA-Z_]+\w*)PHP$strTweet = preg_replace('/(^|\s)#(\w*[a-zA-Z_]+\w*)/', '\1#<a href="http://twitter.com/search?q=%23\2">\2</a>', $strTweet);This regular expression says a # followed by 0 or more characters [a-zA-Z0-9_], followed by an alphabetic character or an underscore (1 or more), followed by 0 or more word characters.http://rubular.com/r/opNX6qC4sG <- test it here. 这篇关于正则表达式有条件地用超链接替换Twitter主题标签的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！