How can I change a file's extension using PHP?

Question

How can I change a file\'s extension using PHP?

Ex: photo.jpg to photo.exe

Answer 1

For regex fans, modified version of Thanh Trung's 'preg_replace' solution that will always contain the new extension (so that if you write a file conversion program, you won't accidentally overwrite the source file with the result) would be:

preg_replace('/\.[^.]+$/', '.', $file) . $extension

Answer 2

You could use basename():

$oldname = 'path/photo.jpg';
$newname = (dirname($oldname) ? dirname($oldname) . DIRECTORY_SEPARATOR  : '') . basename($oldname, 'jpg') . 'exe';

Or for all extensions:

$newname = (dirname($oldname) ? dirname($oldname) . DIRECTORY_SEPARATOR  : '') . basename($oldname, pathinfo($path, PATHINFO_EXTENSION)) . 'exe';

Finally use rename():

rename($oldname, $newname);

Answer 3

Once you have the filename in a string, first use regex to replace the extension with an extension of your choice. Here's a small function that'll do that:

function replace_extension($filename, $new_extension) {
    return preg_replace('/\..+$/', '.' . $new_extension, $filename);
}

Then use the rename() function to rename the file with the new filename.

Answer 4

I needed this to change all images extensions withing a gallery to lowercase. I ended up doing the following:

// Converts image file extensions to all lowercase
$currentdir = opendir($gallerydir);
while(false !== ($file = readdir($currentdir))) {
  if(strpos($file,'.JPG',1) || strpos($file,'.GIF',1) || strpos($file,'.PNG',1)) {
    $srcfile = "$gallerydir/$file";
    $filearray = explode(".",$file);
    $count = count($filearray);
    $pos = $count - 1;
    $filearray[$pos] = strtolower($filearray[$pos]);
    $file = implode(".",$filearray);
    $dstfile = "$gallerydir/$file";
    rename($srcfile,$dstfile);
  }
}

This worked for my purposes.

Answer 5

substr_replace($file , 'png', strrpos($file , '.') +1)

Will change any extension to what you want. Replace png with what ever your desired extension would be.