Removing multiple line breaks

[fagnonk]

So I am parsing a text file with fopen and I need a way to automatically replace multiple line breaks with single line breaks. Currently, my code simply removes all line breaks but I need a way to allow sinlge line breaks. Is this something I could do with regex? If so, how would I go about it?

<?php
$v1 = $_GET['fileId']; 
$v2 = $_GET['title'];

if (isset($_POST[$v1])) {

$str = $_POST[$v1];

$xml = "".$str."";
        									   
$fp = fopen('cms/'.$v1.'.xml', 'w');

$replace = str_replace(chr(10), " ", $xml); //remove carriage returns
$replace2 = str_replace(chr(13), "", $replace); //remove carriage returns

fwrite($fp, $replace2);
fclose($fp);
}


?>	

[scvinodkumar]

Please move this topic to Regex.

 

 

preg_replace("/( )+/","<br>",$xml);

or

preg_replace("/( )+/","</p><p>",$xml);

 

 

[fagnonk]

Cool, that worked well. I can't use html expressions so I changed the code a little to look like:

$replace = preg_replace("/(\r\n)+/","\n\n",$xml);

 

Here comes the difficult part, can you think of a way that I can allow up to two line breaks?