_wp_check_existing_file_names() │ WP 5.3.1

Helper function to check if a file name could match an existing image sub-size file name.

Internal function — this function is designed to be used by the kernel itself. It is not recommended to use this function in your code.

No Hooks.

Returns

bool. True if the tested file name could match an existing file, false otherwise.

Usage

_wp_check_existing_file_names( $filename, $files );
$filename(string) (required)
The file name to check.
$files(array) (required)
An array of existing files in the directory.

Changelog

Since 5.3.1 Introduced.

_wp_check_existing_file_names() code WP 7.1

wp-includes/functions.php 
function _wp_check_existing_file_names( $filename, $files ) {
	$fname = pathinfo( $filename, PATHINFO_FILENAME );
	$ext   = pathinfo( $filename, PATHINFO_EXTENSION );

	// Edge case, file names like `.ext`.
	if ( empty( $fname ) ) {
		return false;
	}

	if ( $ext ) {
		$ext = ".$ext";
	}

	$regex = '/^' . preg_quote( $fname ) . '-(?:\d+x\d+|scaled|rotated)' . preg_quote( $ext ) . '$/i';

	foreach ( $files as $file ) {
		if ( preg_match( $regex, $file ) ) {
			return true;
		}
	}

	return false;
}