反直觉的preg_match行为 - 匹配一系列字符的最简洁方法是什么？

Question

I am looking for ways to match a range of characters and assumed the following regEx would only match characters in the range of hex codes between 20 and 7E. However, it also matches chr(10) (line feed), in fact, the following prints "passed":

echo preg_match("/^[\x20-\x7E]*$/", chr(10)) ? 'passed' : 'failed';

Any idea why and how to match that range?

Answer 1

chr(10) is end of line, so you should add modifier D.

If this modifier is set, a dollar metacharacter in the pattern matches only at the end of the subject string. Without this modifier, a dollar also matches immediately before the final character if it is a newline (but not before any other newlines).

//                               v
echo preg_match("/^[\x20-\x7E]*$/D", chr(10)) ? 'passed' : 'failed';
//                               ^