404-solution / includes / core / RegexHelper.php

RegexHelper.php in 404 Solution trunk, at includes/core/RegexHelper.php

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1	<?php
2
3
4	if (!defined('ABSPATH')) {
5	exit;
6	}
7
8	/**
9	* Polymorphic regex service.
10	*
11	* Owns the three regex primitives the plugin needs across hosts with and
12	* without the PHP mbstring extension, plus the urlLooksLikeRegex URL
13	* classifier. Two concrete implementations live alongside this base class:
14	*
15	* - ABJ_404_Solution_RegexHelperMb - uses mb_ereg / mb_eregi / mb_ereg_replace
16	* - ABJ_404_Solution_RegexHelperPreg - uses native preg_match / preg_replace
17	*
18	* Choose Mb when the mbstring extension is loaded; otherwise Preg. The Preg
19	* variant is also used directly by callers that intentionally want PCRE
20	* regex semantics regardless of host mbstring availability (e.g. SQL
21	* placeholder rewrites that use \d / lookarounds, which mb_ereg's POSIX
22	* syntax cannot express).
23	*
24	* Extracted from ABJ_404_Solution_MbStringAdapter per design-audit-2026-06-02
25	* M201 (parent task i802, this task i826). The adapter previously carried
26	* both byte/multibyte string primitives and regex primitives in the same
27	* interface; splitting regex off lets callers depend on the smaller surface
28	* they actually need.
29	*/
30	abstract class ABJ_404_Solution_RegexHelper {
31
32	/**
33	* Regex match. Mb implementations use POSIX (mb_ereg) syntax; Preg
34	* implementations use PCRE syntax (without delimiters - the helper
35	* supplies them). Callers that intentionally rely on PCRE shorthand
36	* classes (\d, \w, lookarounds, etc.) MUST use the Preg helper
37	* directly, not the polymorphic one.
38	*
39	* @param string $pattern
40	* @param string $string
41	* @param array<int, string>\|null $regs
42	* @return bool\|int
43	*/
44	abstract public function regexMatch(string $pattern, string $string, ?array &$regs = null);
45
46	/**
47	* Case-insensitive regex match. Same syntax caveat as regexMatch().
48	*
49	* @param string $pattern
50	* @param string $string
51	* @param array<int, string>\|null $regs
52	* @return bool\|int
53	*/
54	abstract public function regexMatchi(string $pattern, string $string, ?array &$regs = null);
55
56	/**
57	* Regex replace. Same syntax caveat as regexMatch().
58	*
59	* @param string $pattern
60	* @param string $replacement
61	* @param string $string
62	* @return string\|null
63	*/
64	abstract public function regexReplace($pattern, $replacement, $string);
65
66	/**
67	* Check whether a URL appears to contain regex syntax.
68	*
69	* This is a PCRE-pattern URL classifier used to warn users when a
70	* redirect URL looks like it contains regex syntax but is not marked
71	* as a regex redirect. Implementation is PCRE-only by definition (the
72	* patterns it scans for are PCRE constructs like \d, \w, lookarounds,
73	* etc.), so the same concrete method serves both Mb and Preg variants
74	* - it is not polymorphic.
75	*
76	* @param string\|null $url
77	* @return bool true if the URL appears to contain regex patterns
78	*/
79	public function urlLooksLikeRegex($url) {
80	if ($url === null \|\| $url === '' \|\| !is_string($url)) {
81	return false;
82	}
83
84	$regexIndicators = array(
85	'/$\.\$/', // (.) - common capture-all pattern
86	'/$\.\+$/', // (.+) - one or more of anything
87	'/\(\?\:/', // (?: - non-capturing group
88	'/\(\?=/', // (?= - positive lookahead
89	'/\(\?!/', // (?! - negative lookahead
90	'/\[\^[^\]]+\]/', // [^...] - negated character class
91	'/\[[a-z]-[a-z]\]/i', // [a-z] or [A-Z] - character range
92	'/\[[0-9]-[0-9]\]/', // [0-9] - digit range
93	'/\\\\d/', // \d - digit shorthand
94	'/\\\\w/', // \w - word character shorthand
95	'/\\\\s/', // \s - whitespace shorthand
96	'/\.\/', // . - match anything (greedy)
97	'/\.\+/', // .+ - match one or more of anything
98	'/\.\?/', // .? - match zero or one of anything
99	'/\{\d+,?\d*\}/', // {n} or {n,} or {n,m} - quantifiers
100	'/\\|/', // \| - alternation
101	);
102
103	foreach ($regexIndicators as $pattern) {
104	if (preg_match($pattern, $url)) {
105	return true;
106	}
107	}
108
109	return false;
110	}
111	}
112