Canonicalizes the header name.

Ensures that header names are always treated the same regardless of source. Header names are always case insensitive.

Note that we treat - (dashes) and _ (underscores) as the same character, as per header parsing rules in both Apache and nginx.

$key string Required

Header name.

string Canonicalized name.

File: wp-includes/rest-api/class-wp-rest-request.php. View all references

public static function canonicalize_header_name( $key ) {
	$key = strtolower( $key );
	$key = str_replace( '-', '_', $key );

	return $key;
}