php之将主题标签转换为链接

现在我的第二个问题是，我的脚本无法识别第二个主题标签。
例如，

#heavy / machine gun #test 

<a href="tag.php?id=heavy+">#heavy</a> / machine gun #test 

$words = preg_split("/(#[^\s+[:space:]]+ )/", $str, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY); 
foreach($words as $var => $value) 
{ 
    if($value[0]=='#') 
    { 
     $test[$var]='<a href="tag.php?id='.urlencode(substr($value,1)).'"> '.$value.'</a>'; 
 
     $str=str_replace($value,$test[$var],$descrip); 
    }  
} 

请您参考如下方法:

<?php  
$text = "#heavy / machine gun #test"; 
 
$text = preg_replace('/#(\w+)/', '<a href="tag.php?id=$1">#$1</a>', $text); 
// or 
// $text = preg_replace('/#([^\s+[:space:]]+)/', '<a href="tag.php?id=$1">#$1</a>', $text); 
 
echo $text; 

<a href="tag.php?id=heavy">#heavy</a> / machine gun <a href="tag.php?id=test">#test</a>