$re = '`@sha256:.{64}$`m';
$str = 'redis@sha256:405b4b2fafecf50945309a7ac042ca4a29a624e97613026acff708c1d6af8232
redis:v1.2.3
redis:alpine@sha256:405b4b2fafecf50945309a7ac042ca4a29a624e97613026acff708c1d6af8232
service:version';
preg_match_all($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