的preg_replace不删除自定义标签

Question

上，我要执行正则表达式的内容之间的内容是这样的：

[NON-CA] 
This is for Non CA 
<b> In a New Line </b> 
[/NON-CA] 
[CA] 
This is for CA 
[/CA] 

我想删除的加拿大国家代码基础上的内容，因此如果用户是来自加拿大的只有CA部分将对他可见，而对于其他人只有NON-CA部分将可见。标签之间的内容可以是任何换行符，空格，特殊字符，HTML标记，HTML实体。这是我写的代码：

<?php 
    $content = "[NON-CA]This is for Non CA<b> In a New Line </b> [/NON-CA] [CA]This is for CA[/CA]"; 
    $CApattern = "~\[CA\](.*?)\[/CA\]~"; 
    $NonCApattern = "~\[NON-CA\](.*?)\[/NON-CA\]~";      
    $NonCApatternsReplacement = array(); 
    $Replacepatterns = array();   
    $Replacepatterns[] = "~\[CA\]~"; 
    $Replacepatterns[] = "~\[/CA\]~"; 
    $NonCApatternsReplacement[] = "~\[NON-CA\]~"; 
    $NonCApatternsReplacement[] = "~\[/NON-CA\]~"; 

    if($country_code == "CA"){ //if its the user of country Canada remove the NON-CA Tag         
     $result_p1 = preg_replace($NonCApattern, "", $content, -1, $count);                                 
     $result_p2 = preg_replace($Replacepatterns, "", $result_p1, -1); 
    } 
    else{ //if user is not from CANADA remove CA tag and Text          

     $result_p1 = preg_replace($NonCApatternsReplacement, "", $content, -1);                
     $result_p2 = preg_replace($CApattern,"", $result_p1, -1, $count);                              
    } 
    echo $result_p2 
?> 

因此，如果加拿大用户来到它使内容，如：

[NON-CA] 
This is for Non CA 
<b> In a New Line </b> 
[/NON-CA] 
This is for CA 

这实际上应该是这样的：

This is for CA 

，如果非加拿大用户到达它会产生这样的结果文本：

This is for Non CA 
<b> In a New Line </b>  
[CA] 
This is for CA 
[/CA] 

实际上应该是这样的：

This is for Non CA 
<b> In a New Line </b> 

它不更换/移除根据条件应该是不可见的相应用户的内容的一部分。我的正则表达式有什么问题吗？

Answer 1

您忘记了smodifier与此相匹配，您还将换行符换成.。

s (PCRE_DOTALL) 
    If this modifier is set, a dot metacharacter in the pattern matches all characters, 
    including newlines. Without it, newlines are excluded. 
    This modifier is equivalent to Perl's /s modifier. 
    A negative class such as [^a] always matches a newline character, 
    independent of the setting of this modifier. 

我虽然提供了一个更短的代码：

$string = '[NON-CA] 
This is for Non CA 
<b> In a New Line </b> 
[/NON-CA] 
[CA] 
This is for CA 
[/CA]'; 

$remove = 'NON-CA'; 
$result = preg_replace('/\['.$remove.'\].*?\[\/'.$remove.'\]/s', '', $string); 
echo $result; 

Online demo。

Answer 2

你可以做到这一切在一个替换：

$country_code = 'CA'; // for example 

$content = <<<LOD 
[NON-CA]This is for Non CA<b> In a New Line </b> [/NON-CA] 
[CA]This is for CA[/CA] 
LOD; 

$kr = array('CA', 'NON-CA'); // switch keep/remove 
if ($country_code == 'CA') $kr = array_reverse($kr); 

$pattern = '~\[(?:' . $kr[0] . '][^[]++\[/' . $kr[0] . ']|/?' . $kr[1] . '])~'; 

$result = preg_replace($pattern, '', $content);