php regex replace caracters from filename until extension

Question

I want to replace all characters except 'A-Z','a-z','0-9', '_', '-', '(', ')' from a filename, until the extension.

For the moment i have:

$filename = '23$%^&.234234.%^.234$%$#)(.^$.png';

$fileName = preg_replace('/[^A-Za-z0-9_\-\(\) ]/', '-', $filename);

and i get

$filename : 23------234234----234----)(----png

The problem is that the '.' from extension is removed. The filename can have different extension.

How should i make to change the characters, but not the extension.

Answer 1

You can try with pathinfo function to separate extension from filename and replace unwanted character only in base filename. After everything, just merge those parts:

$filename = '23$%^&.234234.%^.234$%$#)(.^$.png';
$pathinfo = pathinfo($filename);
$filename = implode('.', array(
  preg_replace('/[^A-Za-z0-9_\-\(\) ]/', '-', $pathinfo['filename']),
  $pathinfo['extension']
));

var_dump($filename);

Output:

string '23-----234234----234----)(---.png' (length=33)