Question

The following code removes comments, line breaks, and extra space from HTML and PHP files, but a problem I have is when the original file has <<<EOT; in it. What regex rule would I use to add a linebreak before and after <<<EOT; from $pre6?

//a bit messy, but this is the core of the program. removes whitespaces, line breaks, and comments. sometimes makes EOT error.
$pre1 = preg_replace('#<!--[^\[<>].*?(?<!!)-->#s', '', preg_replace('~>\s+<~', '><', trim(preg_replace('/\s\s+/', ' ', php_strip_whitespace(stripslashes(htmlspecialchars($uploadfile)))))));
$pre2 = preg_replace("/(^[\r\n]*|[\r\n]+)[\s\t]*[\r\n]+/", "\n", $pre1);
$pre3 = str_replace(array("\r\n", "\r"), "\n", $pre2);
$pre4 = explode("\r\n", $pre3);
$pre5 = array();
foreach ($pre4 as $i => $line) {
    if(!empty($line))
        $pre5[] = trim($line);
}
$pre6 = implode($pre5);
echo $pre6;

Answer 1

To match <<<EOT, you could use <{3}[A-Z]{3}, or several other patterns, depending on how strictly you want to match that exact text.

Oh, I see what you’re after now. I’m not great with PHP, but in regular expressions, you can capture a named group and then refer to that group in a replacement operation. You could use the following to capture <<<EOT into a group named Capture:

(?<Capture><{3}[A-Z]{3})

I think in PHP you can refer to it using something like:

$regs['Capture']

So maybe you’re after a replacement parameter value of something like:

"\r\n".$regs['Capture']."\r\n"

…if $regs was the parameter passed to the replace operation.