PHP Check File Extension

PHP check file extension

pathinfo is what you're looking for

PHP.net

$file_parts = pathinfo($filename);

switch($file_parts['extension'])
{
    case "jpg":
    break;

    case "exe":
    break;

    case "": // Handle file extension for files ending in '.'
    case NULL: // Handle no file extension
    break;
}

How to get a file's extension in PHP?

People from other scripting languages always think theirs is better because they have a built-in function to do that and not PHP (I am looking at Pythonistas right now :-)).

In fact, it does exist, but few people know it. Meet pathinfo():

$ext = pathinfo($filename, PATHINFO_EXTENSION);

This is fast and built-in. pathinfo() can give you other information, such as canonical path, depending on the constant you pass to it.

Remember that if you want to be able to deal with non ASCII characters, you need to set the locale first. E.G:

setlocale(LC_ALL,'en_US.UTF-8');

Also, note this doesn't take into consideration the file content or mime-type, you only get the extension. But it's what you asked for.

Lastly, note that this works only for a file path, not a URL resources path, which is covered using PARSE_URL.

Enjoy

Check file extension in upload form in PHP

Using if( $ext !== 'gif') might not be efficient. What if you allow like 20 different extensions?

Try:

$allowed = array('gif', 'png', 'jpg');
$filename = $_FILES['video_file']['name'];
$ext = pathinfo($filename, PATHINFO_EXTENSION);
if (!in_array($ext, $allowed)) {
    echo 'error';
}

How to check for the correct file extension in PHP?

Your problem is here:

$file = fopen($_FILES['upload_csv']['tmp_name'], 'r');
$ext = pathinfo($file, PATHINFO_EXTENSION);

fopen returns a file handle for use reading and writing a file, but pathinfo is expecting a string containing a filename (optionally, with a path), but you're giving it a file handle.

You should, in any case, be looking at $_FILES['upload_csv']['name'], which is the original name of the file, and extracting the file extension from that.

how to check for certain file extension in a folder with php

Use the glob() function.

$result = glob("my/folder/uploads/*.zip");

It will return an array with the *.zip-files.

How to check if multiple files' extensions are in_array

As mentioned by the commenters, your $allowed array contains a list of valid mime-types, not extensions. You must decide what you want to use to check the validity of the file.

If you decide to go with the pure file extension, then in the loop you must also extract the extension, and compare that to a new list, one that contains expected valid extensions. Something like this:

$files = ['orange.jpg', 'apple.jpeg'];
$allowed  = ['jpg', 'jpeg', 'png', 'gif'];

foreach($files as $names) {
    $pathinfo = pathinfo($names);  /* split path in its components */
    $extension = strtolower($pathinfo['extension']);  /* extract the extension and normalize to lowercase */

    if (in_array($extension, $allowed)) {
        echo "Valid image extension";
    } else {
        echo "Invalid image extension";
    }
}

How to get the file extension in PHP?

No need to use string functions. You can use something that's actually designed for what you want: pathinfo():

$path = $_FILES['image']['name'];
$ext = pathinfo($path, PATHINFO_EXTENSION);

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