正则表达式问题：如何在文本不含指定单词时匹配全部内容

Got it, let's figure out the right regex for your Drupal backend in PHP. Since PHP uses PCRE-style regex, we can craft a pattern that meets your exact needs: matching the entire multi-line text only if it doesn't contain the word "student" (case-insensitive).

The Regex Pattern #

/^(?:(?!student).)*$/is

Breakdown of the Pattern #

Let's break down what each part does:

• ^ : Anchors the match to the start of the string
• (?:(?!student).)* : A non-capturing group that repeats for every character:
  • (?!student) : Negative lookahead that checks the current position doesn't have "student" (case-insensitive, thanks to the i modifier) coming up next
  • . : Matches any single character (including newlines, thanks to the s modifier)
• $ : Anchors the match to the end of the string
• i : Makes the match case-insensitive (so "Student", "STUDENT", etc. are all detected)
• s : Enables DOTALL mode, which lets the . character match newlines—critical for multi-line text

How to Use It in PHP #

Here's a quick example of how you'd implement this in your Drupal code:

$targetText = "I need to think of something to write here. I am an alumni of the college. The blue cat is blue the red cat is red.";
$regexPattern = '/^(?:(?!student).)*$/is';

if (preg_match($regexPattern, $targetText, $matches)) {
    // Text doesn't contain "student" (case-insensitive) — full text matched
    $matchedContent = $matches[0];
    // Do something with $matchedContent in your Drupal logic
} else {
    // Text contains "student" in any case — no match
}

This pattern will reliably check the entire multi-line text, and only match if "student" (in any case) is nowhere to be found. It works perfectly with PHP's preg_match function, which is what you'll use in Drupal's backend.

内容的提问来源于stack exchange，提问作者Mona NM