<?php
 
$headerETags = array();
 
$IfNoneMatchTestPattern = '#^((W/)?"[\x00-\x7f]*?", )*(W/)?"[\x00-\x7f]*?"$#';
$IfNoneMatchEtagsPattern = '#(?:W/)?("[\x00-\x7f]*?")(?=$|, (?:W/)?"[\x00-\x7f]*?")#';
 
if (!preg_match($IfNoneMatchTestPattern, $headerValue)) {
 
    write2log("Нестандартный Etag $headerValue.", ADD_CLIENT_HEADERS);            
    $headerETags = array($headerValue);
 
} elseif (preg_match_all($IfNoneMatchEtagsPattern, $headerValue, $headerETags)) {
 
    $headerETags = $headerETags[1]; // первая подмаска
 
} else {
 
	write2log("If-None-Match прошел проверку, но не дал совпадений. Шта?", ADD_CLIENT_HEADERS);
	$headerETags = array($headerValue);
 
}

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