我有这个文本，我试图删除所有内部引号，只保留一个引用级别。引号内的文本包含任何字符，甚至换行符等。这可以使用正则表达式还是我必须编写一个小解析器？
[quote=foo]I really like the movie. [quote=bar]World
War Z[/quote] It's amazing![/quote]
This is my comment.
[quote]Hello, World[/quote]
This is another comment.
[quote]Bye Bye Baby[/quote]
这是我想要的文字：
[quote=foo]I really like the movie. It's amazing![/quote]
This is my comment.
[quote]Hello, World[/quote]
This is another comment.
[quote]Bye Bye Baby[/quote]
这是我在 PHP 中使用的正则表达式：
%'[quote's*(=[a-zA-Z0-9'-_]*)?'](.*)'[/quote']%si
我也尝试了这个变体，但它与.或,不匹配，我不知道在报价中还能找到什么：
%'[quote's*(=[a-zA-Z0-9'-_]*)?'](['w's]+)'[/quote']%i
问题出在这里：
(.*)
你可以使用这个：
$result = preg_replace('~'G(?!'A)(?>('[quote'b[^]]*](?>[^[]+|'[(?!/?quote)|(?1))*'[/quote])|(?<!'[)(?>[^[]+|'[(?!/?quote))+'K)|'[quote'b[^]]*]'K~', '', $text);
详：
'G(?!'A) # contiguous to a precedent match
(?> ## content inside "quote" tags at level 0
( ## nested "quote" tags (group 1)
'[quote'b[^]]*]
(?> ## content inside "quote" tags at any level
[^[]+
| # OR
'[(?!/?quote)
| # OR
(?1) # repeat the capture group 1 (recursive)
)*
'[/quote]
)
|
(?<!'[) # not preceded by an opening square bracket
(?> ## content that is not a quote tag
[^[]+ # all that is not a [
| # OR
'[(?!/?quote) # a [ not followed by "quote" or "/quote"
)+'K # repeat 1 or more and reset the match
)
| # OR
'[quote'b[^]]*]'K # "quote" tag at level 0
使用此模式
'[quote=?[^']]*'][^'[]*'[/quote'](?=((.(?!'[q))*)'[/)
并替换为任何内容就像在这个例子中
我认为编写解析器会更容易。
使用正则表达式查找[quote]和['quote]，然后分析结果。
preg_match_all('#('[quote[^]]*']|'['/quote'])#', $bbcode, $matches, PREG_OFFSET_CAPTURE);
$nestlevel = 0;
$cutfrom = 0;
$cut = false;
$removed = 0
foreach($matches(0) as $quote){
if (substr($quote[0], 0, 1) == '[') $nestlevel++; else $nestlevel--;
if (!$cut && $nestlevel == 2){ // we reached the first nested quote, start remove here
$cut = true;
$cutfrom = $quote[1];
}
if ($cut && $nestlevel == 1){ // we closed the nested quote, stop remove here
$cut = false;
$bbcode = substr_replace($bbcode, '', $cutfrom - $removed, $quote[1] + 8 - $removed); // strlen('['quote]') = 8
$removed += $quote[1] + 8 - $cutfrom;
}
);