Question

Whats is the best way to obtain the content between two strings e.g.

ob_start();
include('externalfile.html'); ## see below
$out = ob_get_contents();
ob_end_clean();

preg_match('/{FINDME}(.|\n*)+{\/FINDME}/',$out,$matches);
$match = $matches[0];

echo $match;

## I have used .|\n* as it needs to check for new lines. Is this correct?

## externalfile.html

{FINDME}
Text Here
{/FINDME}

For some reason this appears to work on one place in my code and not another. Am I going about this in the right way? Or is there a better way?

Also is output buffer the way to do this or file_get_contents?

Thanks in advance!

Answer 1

• Use # instead of / so you dont have to escape them.

• The modifier s allows . to match newlines.

• { may be the start of a {n} or {n,m} quantifier. The closing } has no special meaning, but escaping it doesn’t cause an error.

• The basic

    preg_match('#\{FINDME}(.+)\{/FINDME}#s', $out, $matches);
  

• The advanced for various tags etc (styling is not so nice by the javascript).

    $delimiter = '#';
    $startTag = '{FINDME}';
    $endTag = '{/FINDME}';
    $regex = $delimiter . preg_quote($startTag, $delimiter) 
                        . '(.*?)' 
                        . preg_quote($endTag, $delimiter) 
                        . $delimiter 
                        . 's';
    preg_match($regex,$out,$matches);
  

Put this code in a function

• For any file which you do not want to execue any stray php code, you should use file_get_contents. include/require should not even be an option there.