$re = '/\A
(?<major>0|[1-9]\d*)\.
(?<minor>0|[1-9]\d*)\.
(?<patch>0|[1-9]\d*)
(?:
-(?<prerelease>
(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)
(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*
)
)?
(?:
\+(?<buildmetadata>[0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*)
)?
\Z
/mx';
$str = '1.0.0';
preg_match_all($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