3v4l.org

run code in 300+ PHP versions simultaneously
<?php $html=<<<HTML <img src="/relative/url/img.jpg" /> <form action="/"> <a href='/relative/url/'>Note the Single Quote</a> <img src="//site.com/protocol-relative-img.jpg" /> HTML; $base='https://example.com'; echo preg_replace('~(?:src|action|href)=[\'"]\K/(?!/)[^\'"]*~',"$base$0",$html);
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
<img src="https://example.com/relative/url/img.jpg" /> <form action="https://example.com/"> <a href='https://example.com/relative/url/'>Note the Single Quote</a> <img src="//site.com/protocol-relative-img.jpg" />
preferences:
104.15 ms | 2057 KiB | 4 Q