$re = '/\/img\/a\/[^\/]/m';
$str = 'href="https://blogger.googleusercontent.com/img/a/AVvXsEhb-vB59M2NTWyWvDlMemRdgT0XMKdjB4NMH02iP4Nb7HbzHwq5ZObxjEC1_oLne6xpUhIkrkpyWEdMX9ck-aU5h1JXdpSw-GhbV90QBEi2xigGLQdoSswWuQtPNNCyWMRJiT2XnEadx170jUDbtL-AQKKzYyarCoj8=s1727"
src="https://blogger.googleusercontent.com/img/a/AVvXsEhb-vB59M2NTWyWvDlMemRdgT0XMKdjB4NMH02iP4Nb7HbzHwq5ZObxjEC1_oLne6xpUhIkrkpyWEdMX9ck-aU5h1JXdpSw-GhbV90QBEi2xigGLQdoSswWuQtPNNCyWMRJiT2XnEadx170jUDbtL-AQKKzYyarCoj8=w400-h183"';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php