| ################ |
| 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 :doc:`Config Library <../libraries/config>` |
| documentation for more information. |
| |
| .. important:: This function only returns values set in your configuration |
| files. It does not take into account config values that are |
| dynamically set at runtime. |
| |
| 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. |
| |
| get_mimes() |
| =========== |
| |
| This function returns the MIMEs array *from config/mimes.php*. |
| |
| is_https() |
| ========== |
| |
| Returns TRUE if a secure (HTTPS) connection is used and FALSE |
| in any other case (including non-HTTP requests). |