自定义PHP标记系统帮助，查找用户名

Question

I am currently making a tag system within my profile page of my website. If the user specifies: +tag[username] where username is equal to a username that the person is friends with, it will preg_replace the tag with a link to the user. Finding the +tag using strpos is easy, but the question i am asking is how to pull the username as a variable. e.g: if $text = 'hey +tag[matty] how are you!'

if (strpos($text, '+tag[//username//]' !== false)) {
//get //username// and store as $username
} 

so that it would look like this:

if (strpos($text '+tag[//username//]' !== false) {
   $username = "matty";
}

thankyou to all who reply in advance :)

Answer 1

How about using the regular expression matching function preg_match?

$subject = "hey +tag[matty] how are you!";
$pattern = '/\+tag\[(.*?)\]/';
preg_match($pattern, $subject, $matches);
$username = $matches[1];
echo $username;

To match multiple instances of the tag, you'd want to use preg_match_all:

$subject = "Hey +tag[matty]! Want to meet up with +tag[keshia] later?";
$pattern = '/\+tag\[(.*?)\]/';
preg_match_all($pattern, $subject, $matches);
foreach($matches[1] as $username){
    echo $username.'<br>';
}