embedded-tags.php

<?php
echo "<pre>";

$subject = "This is a test {pause}3{/pause} for embedded tags. {shake}1.5{/shake} Tada! {wait}keySpace{/wait}\n";

$pattern = "#{([\w]+)}(.*?){/\\1}\s#";
preg_match_all($pattern, $subject, $matches);
$split = preg_split($pattern, $subject);

print_r($subject);
echo "\n";
print_r($split);
print_r($matches);
echo "\n";

$cmd = 0;
//for each split string
foreach($split as $m) {
	$chars = str_split($m);
	
	//for each character
	foreach($chars as $c) {
		//output it
		echo "$c";
	}

	//fire tag command
	if ($cmd < count($matches[1])) echo "\ncmd:". $matches[1][$cmd] ."(". $matches[2][$cmd] .")\n";
	$cmd++;
}

echo "</pre>";
?>

embedded-tags.txt

This is a test {pause}3{/pause} for embedded tags. {shake}1.5{/shake} Tada! {wait}keySpace{/wait}

Array
(
    [0] => This is a test 
    [1] => for embedded tags. 
    [2] => Tada! 
    [3] => 
)
Array
(
    [0] => Array
        (
            [0] => {pause}3{/pause} 
            [1] => {shake}1.5{/shake} 
            [2] => {wait}keySpace{/wait}

        )

    [1] => Array
        (
            [0] => pause
            [1] => shake
            [2] => wait
        )

    [2] => Array
        (
            [0] => 3
            [1] => 1.5
            [2] => keySpace
        )

)

This is a test 
cmd:pause(3)
for embedded tags. 
cmd:shake(1.5)
Tada! 
cmd:wait(keySpace)