ZipArchive:: check file extension - php

Question

The following code unzips my uploaded file and extracts everything in a directory called PDF. It then proceeds to iterate through the files and return files to download.
My problem is I need to check the file extension. I would only like to return the PDF file back to the user but some of the uploaded files have unnecessary images.
How can I check the contents of the file to ensure the unzipped file is a PDF & only the PDF is returned back to the user?
<?php
$zip = new ZipArchive;
$res = $zip->open('/download/xxxx.zip');
if ($res === TRUE) {
$zip->extractTo('/download/pdf/');
for($i = 0; $i < $zip->numFiles; $i++)
{
echo 'download';
}
$zip->close();
} else {
echo 'Something went wrong :( ';
}
?>
Thank you
Dexas solution worked for me. Here's the code if you need it
I've added in comments to show what I've changed.
<?php
$zip = new ZipArchive;
$res = $zip->open('/download/xxxxx.zip');
if ($res === TRUE) {
$zip->extractTo('/download/pdf/');
for($i = 0; $i < $zip->numFiles; $i++)
{
//Load files into variable which can be used with the following... ['dirname'], ['basename'], ['extension'], ['filename']
$path_parts = pathinfo('/download/pdf/' . $zip->getNameIndex($i));
//If the extension is equal to PDF echo the code out
if($path_parts['extension'] === 'pdf')
{
echo 'download';
}
}
$zip->close();
} else {
echo 'Something went wrong :( ';
}
?>

Answer 1

You can check it's MIME type using finfo
$finfo = new finfo(FILEINFO_MIME);
$type = $finfo->file('/path/to/file');
if($type === 'application/pdf')
{
//do your stuff
}
For the extension part you can use pathinfo
$ext = pathinfo('/path/to/file', PATHINFO_EXTENSION);
In the end you should check both and decide is it PDF or not.