[code]

$search = '<img border="0" src="http://aaa.com/0.jpg" width="100" height="100">
<br><img border="0" src="http://aaa.com/1.jpg" width="100" height="100">
<br><img border="0" src="http://aaa.com/2.jpg" width="100" height="100">';

$replace = '<img border="0" src="위에서 추출한 이미주소 첫번째" width="100" height="100">
<br>안녕하세요~
<br><br>날씨가 많이 춥네요
<br><img border="0" src="위에서 추출한 이미주소 두번째" width="100" height="100">
<br>감기조심하세요
<br><img border="0" src="위에서 추출한 이미주소 세번째" width="100" height="100">';

class UrlChange {
    var $matches, $i = 0, $regex = '/(?<=src=")[^"]+/', $val = '';
    function __construct($search, $replace) {
        preg_match_all($this->regex, $search, $matches);
        $this->matches = $matches[0];
        $this->val = preg_replace_callback($this->regex, array($this, 'call'), $replace);
     }
    function call($m) { return $this->matches[$this->i++]; }
}

$a = new UrlChange($search, $replace);
echo $a->val;
[/code]

https://sir.kr/qa/223379