validateMimeType()

Validate the MIME type of a file against a list of allowed types.

Parameters

$file : string

Path to the file to validate.

$allowedMimeTypes : array<string|int, mixed>

List of allowed MIME types. Can include strings or arrays of strings.

Tags

throws

FileException

If the MIME type is not allowed or cannot be determined.

example

Basic usage: validate that an uploaded file is a PDF or plain text file.

use function oihana\files\validateMimeType;
use oihana\files\exceptions\FileException;

$file = __DIR__ . '/example.txt';
file_put_contents($file, 'Some text content');

try
{
    validateMimeType($file, ['text/plain', 'application/pdf']);
    echo "File is valid.";
}
catch ( FileException $e )
{
    echo "Error: " . $e->getMessage();
}

unlink($file);

Accepting multiple MIME types (grouped by type):

$allowedTypes =
[
    ['image/png', 'image/jpeg'],
    ['application/pdf'],
];
validateMimeType('photo.jpg', $allowedTypes);

Error example:

try
{
    validateMimeType('fake.exe', ['image/png', 'image/jpeg']);
}
catch (FileException $e)
{
    echo "Validation failed: " . $e->getMessage();
}

Notes:

• Both the detected type and the allowed ones are compared by the reference name of their format (normalizeMimeType()) : ['audio/wav'] accepts a WAV file that finfo reports as audio/x-wav. Only names of the same format meet — an image never passes for a script. The error message quotes the type as finfo reported it.
• Allowing audio/webm allows a WebM video too : finfo reports video/webm for both, the container being the same.
• This function uses mime_content_type(), which relies on the system's file command or magic database.
• For consistent results across platforms, ensure the PHP fileinfo extension is enabled.

author

Marc Alcaraz (ekameleon)

since

1.0.0