| ################ |
| Common Functions |
| ################ |
| |
| CodeIgniter uses a few functions for its operation that are globally |
| defined, and are available to you at any point. These do not require |
| loading any libraries or helpers. |
| |
| is_php('version_number') |
| ========================== |
| |
| is_php() determines of the PHP version being used is greater than the |
| supplied version_number. |
| |
| :: |
| |
| if (is_php('5.3.0')) { $str = quoted_printable_encode($str); } |
| |
| Returns boolean TRUE if the installed version of PHP is equal to or |
| greater than the supplied version number. Returns FALSE if the installed |
| version of PHP is lower than the supplied version number. |
| |
| is_really_writable('path/to/file') |
| ==================================== |
| |
| is_writable() returns TRUE on Windows servers when you really can't |
| write to the file as the OS reports to PHP as FALSE only if the |
| read-only attribute is marked. This function determines if a file is |
| actually writable by attempting to write to it first. Generally only |
| recommended on platforms where this information may be unreliable. |
| |
| :: |
| |
| if (is_really_writable('file.txt')) { echo "I could write to this if I wanted to"; } else { echo "File is not writable"; } |
| |
| config_item('item_key') |
| ========================= |
| |
| The :doc:`Config library <../libraries/config>` is the preferred way of |
| accessing configuration information, however config_item() can be used |
| to retrieve single keys. See Config library documentation for more |
| information. |
| |
| show_error('message'), show_404('page'), log_message('level', |
| 'message') |
| ========== |
| |
| These are each outlined on the :doc:`Error Handling <errors>` page. |
| |
| set_status_header(code, 'text'); |
| ================================== |
| |
| Permits you to manually set a server status header. Example:: |
| |
| set_status_header(401); // Sets the header as: Unauthorized |
| |
| `See here <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html>`_ for |
| a full list of headers. |
| |
| remove_invisible_characters($str) |
| =================================== |
| |
| This function prevents inserting null characters between ascii |
| characters, like Java\\0script. |
| |
| html_escape($mixed) |
| ==================== |
| |
| This function provides short cut for htmlspecialchars() function. It |
| accepts string and array. To prevent Cross Site Scripting (XSS), it is |
| very useful. |