how to change the name of images with different extensions

[php_guest]

there are 4 allowed types of images: jpg, jpeg, png, gif. I want to change the name of each image, but the extension must be the kept.

 

How to remove everything what is before .jpg or .jpeg. or .png or .gif?

 

Thank you.

[Ken2k7]

preg_replace('#.*\.(.*)$#', '.' . $1, $img);

 

?

[php_guest]

I just found something easier to do what I want:

function getExtension($str) {

$i = strrpos($str,".");

if (!$i) { return ""; }

$l = strlen($str) - $i;

$ext = substr($str,$i+1,$l);

return $ext;

}

[php_guest]

Even easier, just simple pathinfo('$filename'). Sorry to not check this before I put the question.

 

So I put this code to change image name to put it into database:

 

$ext = pathinfo('$filename');

 

$len = 16;

$base='ABCDEFGHKLMNOPQRSTWXYZabcdefghjkmnpqrstwxyz123456789';

$max=strlen($base)-1;

$string='';

mt_srand((double)microtime()*1000000);

while (strlen($string)<$len+1)

  $string.=$base{mt_rand(0,$max)};

 

$newname=$string.".".$ext['extension'];

 

[Daniel0]

php_guest, it's no longer needed to seed the PRNG in PHP.