add lines in realtime with preg_replace

Question

I was wondering if it's possible to fetch the regular expression match in preg_replace and manipulate it in real time (iow... at the same preg_replace command)...

This is not the proper syntax but just to get the idea...

    $test = <<<EOF

    <!--

    THIS IS COMMENT #1

    -->

    <!--

    THIS IS COMMENT #2

    -->
    EOF;

    $test = preg_replace('#<--(.|\s)*?-->#', 'Additional line to the html comment without delete the real comment' . '#<--(.|\s)*?-->#' .'<BR/>' , $test);

    //iow... how can I replace this '#<--(.|\s)*?-->#'
//to this : 'Additional line to the html comment without delete the real comment' . '#<--(.|\s)*?-->#' .'<BR/>'

    echo $test;

    /*
    I expect to get this :

    <!--
    Additional line to the html comment without delete the real comment
    THIS IS COMMENT #1

    -->

    <!--
    Additional line to the html comment without delete the real comment
    THIS IS COMMENT #2

    -->
    */

Any idea? :/

Answer 1

How about:

$test = preg_replace('#(<--)(.+?)(-->)#', '$1Additional line to the html comment without delete the real comment$2$3' , $test);

Answer 2

If your comments have always two newlines at the begining, a quick way without regex:

$trans = array("<!--\n\n" => "<!--\n$newline",
               "<!--\r\n\r\n" => "<!--\r\n$newline");

$str = strtr($str, $trans);