Using Perl-Compatible Regular Expressions
Matching patterns in PCRE is done using preg_match() if only one occurrence is searched for, or preg_match_all() if multiple occurrences may exist. The syntax is the same as for ereg(): first the pattern, then the string, then the resulting array. However, the way the pattern is provided is slightly different. You need delimiters; most of the time slashes are used. After the delimiter, you can provide further instructions. Instruction g lets the search be done globally (for multiple matches), whereas instruction i deactivates case sensitivity. Searching in Strings Using PCRE (preg_match.php) <?php $string = 'This site runs on PHP ' . phpversion(); preg_match('/php ((\d)\.\d\.\d+)/i', $string, $matches); vprintf('Match: %s<br /> Version: %s; Major: %d.', $matches); ?> The function preg_match_all() works exactly the same; however, the resulting array is a multi-dimensional one. Each entry in this array is an array of matches as it would have been returned by preg_match(). The following code shows this. Finding Multiple Matches in Strings Using PCRE (preg_match_all.php) <?php $string = 'This site runs on PHP ' . phpversion(); preg_match('/php ((\d)\.\d\.\d+)/i', $string, $matches); vprintf('Match: %s<br /> Version: %s; Major: %d.', $matches); ?> |
