Runs through a bunch of *.tpl files to update syntax from Smarty2 to Smarty3 -- no whitespace around tags

fix-smarty.php

<?php

$dir = new RecursiveDirectoryIterator(dirname(__FILE__));
$iterator = new RecursiveIteratorIterator($dir);

$pattern = '~\{(.+?)\}~im';

$start_char = '{';
$end_char   = '}';

class FileParser implements Iterator
{
	private $position = 0;
    private $contents = null;  

    public function __construct($contents) {
        $this->position = 0;
        $this->contents = $contents;
    }

    function rewind() {
        $this->position = 0;
    }

    function current() {
        return $this->contents{$this->position};
    }

    function key() {
        return $this->position;
    }

    function next() {
        ++$this->position;
    }

    function valid() {
        return isset($this->contents{$this->position});
    }
    
    function moveTo($char) {
    	while ($this->valid()) {
    		if ($this->current() === $char) {
    			return $this->current();
    		}
    		
    		$this->next();
    	}
    	
    	return false;
    }
    
    function captureUntil($char) {
    	$chars = '';
    	
    	while ($this->valid()) {
    		$chars .= $this->current();
    		if ($this->current() === $char) {
    			return $chars;
    		}
    		
    		$this->next();
    	}
    	
    	return $chars;
    }
}

foreach (new RegexIterator($iterator, '/^.+\.tpl$/i', RecursiveRegexIterator::GET_MATCH) AS $tpl) {
	$contents = file_get_contents($tpl[0]);
	
	printf("Checking: %s\n", str_replace(dirname(__FILE__), '', $tpl[0]));

	$parser = new FileParser($contents);
	$dirty = false;
	
	while ($parser->moveTo($start_char) !== false) {
		$start = $parser->key();
		$tag = $parser->captureUntil($end_char);
		

		if ($tag == '{literal}') {
      		while ($tag !== '{/literal}') {
      			if ($parser->moveTo($start_char) === false) {
      				break;
      			}
      			
      			$tag = $parser->captureUntil($end_char);
      		}
      		break;
      	}
      	
      	$tagContents = substr($tag, 1, -1);
		if (trim($tagContents) === $tagContents) {
			// no whitespace == all good
			continue;
		}
		
		$end = $parser->key();
		
		$newTag = sprintf('{%s}', trim($tagContents));
		
		$contents = str_replace($tag, $newTag, $contents);
		$dirty = true;
    }
    
    if ($dirty === true) {
    	file_put_contents($tpl[0], $contents);
    	
    	printf("Fixed: %s\n", str_replace(dirname(__FILE__), '', $tpl[0]));
    }
}