| drupal_build_js_cache | includes/common.inc | Aggregate JS files, putting them in the files directory. |
| file_check_directory | includes/file.inc | Check that the directory exists and is writable. Directories need to
have execute permissions to be considered a directory by FTP servers, etc. |
| file_create_path | includes/file.inc | Make sure the destination is a complete path and resides in the file system
directory, if it is not prepend the file system directory. |
| file_save_data | includes/file.inc | Save a string to the specified destination. |
