Functions that are wrappers or custom implementations of PHP functions.

Certain PHP functions should not be used in Backdrop. Instead, Backdrop's replacement functions should be used.

For example, for improved or more secure UTF8-handling, or RFC-compliant handling of URLs in Backdrop.

For ease of use and memorizing, all these wrapper functions use the same name as the original PHP function, but prefixed with "backdrop_". Beware, however, that not all wrapper functions support the same arguments as the original functions.

You should always use these wrapper functions in your code.


  $my_substring = substr($original_string, 0, 5);


  $my_substring = backdrop_substr($original_string, 0, 5);


core/includes/, line 10
Common functions that many Backdrop modules will need to reference.


Namesort descending Location Description
backdrop_basename core/includes/ Gets the filename from a given path.
backdrop_chmod core/includes/ Sets the permissions on a file or directory.
backdrop_dirname core/includes/ Gets the name of the directory from a given path.
backdrop_http_build_query core/includes/ Parses an array into a valid, rawurlencoded query string.
backdrop_json_decode core/includes/ Converts an HTML-safe JSON string into its PHP equivalent.
backdrop_json_encode core/includes/ Converts a PHP variable into its JavaScript equivalent.
backdrop_mkdir core/includes/ Creates a directory using Backdrop's default mode.
backdrop_move_uploaded_file core/includes/ Moves an uploaded file to a new location.
backdrop_parse_url core/includes/ Parses a system URL string into an associative array suitable for url().
backdrop_realpath core/includes/ Resolves the absolute filepath of a local URI or filepath.
backdrop_register_shutdown_function core/includes/ Registers a function for execution on shutdown.
backdrop_rmdir core/includes/ Removes a directory.
backdrop_session_regenerate core/includes/ Called when an anonymous user becomes authenticated or vice-versa.
backdrop_session_start core/includes/ Starts a session forcefully, preserving already set session data.
backdrop_set_time_limit core/includes/ Attempts to set the PHP maximum execution time.
backdrop_strlen core/includes/ Counts the number of characters in a UTF-8 string.
backdrop_strtolower core/includes/ Lowercase a UTF-8 string.
backdrop_strtoupper core/includes/ Uppercase a UTF-8 string.
backdrop_substr core/includes/ Cuts off a piece of a string based on character indices and counts.
backdrop_tempnam core/includes/ Creates a file with a unique filename in the specified directory.
backdrop_ucfirst core/includes/ Capitalizes the first letter of a UTF-8 string.
backdrop_unlink core/includes/ Deletes a file.
backdrop_xml_parser_create core/includes/ Prepares a new XML parser.