What potential pitfalls should be considered when using regular expressions and matching functions like preg_match in PHP, especially when dealing with complex text patterns?

When using regular expressions and matching functions like preg_match in PHP to handle complex text patterns, potential pitfalls to consider include the risk of inefficient or incorrect pattern matching, potential security vulnerabilities like denial of service attacks due to catastrophic backtracking, and difficulties in maintaining and debugging complex regex patterns. To mitigate these risks, it's important to thoroughly test regex patterns, avoid overly complex expressions, and consider using tools like regex debuggers to analyze and optimize patterns. 

// Example of using a simpler regex pattern and adding appropriate error handling

$text = "This is a sample text with a phone number 123-456-7890";

$pattern = '/\b\d{3}-\d{3}-\d{4}\b/';

if (preg_match($pattern, $text, $matches)) {
    echo "Phone number found: " . $matches[0];
} else {
    echo "No phone number found";
}

Keywords

regular expressions preg_match PHP complex text patterns pitfalls

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