What potential pitfalls should be avoided when using regular expressions in PHP to extract text patterns?

One potential pitfall when using regular expressions in PHP to extract text patterns is not properly escaping special characters in the pattern. This can lead to unexpected behavior or errors in the regex matching process. To avoid this issue, it is important to use the preg_quote() function to escape special characters in the pattern before using it in the regular expression.

// Example of properly escaping special characters in a regex pattern
$pattern = '/^[\w\s]+$/';
$escaped_pattern = preg_quote($pattern, '/');