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

Better way:

substr($filename, 0, -strlen(pathinfo($filename, PATHINFO_EXTENSION))).$new_extension

Changes made only on extension part. Leaves other info unchanged.

It's safe.

Answer 2

Many good answers have been suggested. I thought it would be helpful to evaluate and compare their performance. Here are the results:

• answer by Tony Maro (pathinfo) took 0.000031040740966797 seconds. Note: It has the drawback for not including full path.
• answer by Matt (substr_replace) took 0.000010013580322266 seconds.
• answer by Jeremy Ruten (preg_replace) took 0.00070095062255859 seconds.

Therefore, I would suggest substr_replace, since it's simpler and faster than others.

Just as a note, There is the following solution too which took 0.000014066696166992 seconds. Still couldn't beat substr_replace:

$parts = explode('.', $inpath);
$parts[count( $parts ) - 1] = 'exe';
$outpath = implode('.', $parts);

Answer 3

http://www.php.net/rename

Answer 4

Just replace it with regexp:

$filename = preg_replace('"\.bmp$"', '.jpg', $filename);

You can also extend this code to remove other image extensions, not just bmp:

$filename = preg_replace('"\.(bmp|gif)$"', '.jpg', $filename);

Answer 5

Replace extension, keep path information

function replace_extension($filename, $new_extension) {
    $info = pathinfo($filename);
    return ($info['dirname'] ? $info['dirname'] . DIRECTORY_SEPARATOR : '') 
        . $info['filename'] 
        . '.' 
        . $new_extension;
}

Answer 6

In modern operating systems, filenames very well might contain periods long before the file extension, for instance:

my.file.name.jpg

PHP provides a way to find the filename without the extension that takes this into account, then just add the new extension:

function replace_extension($filename, $new_extension) {
    $info = pathinfo($filename);
    return $info['filename'] . '.' . $new_extension;
}