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Diffstat (limited to 'user_guide_src/source/general/common_functions.rst')
| -rw-r--r-- | user_guide_src/source/general/common_functions.rst | 186 |
1 files changed, 151 insertions, 35 deletions
diff --git a/user_guide_src/source/general/common_functions.rst b/user_guide_src/source/general/common_functions.rst index 70563b8d2..7917d3239 100644 --- a/user_guide_src/source/general/common_functions.rst +++ b/user_guide_src/source/general/common_functions.rst @@ -6,58 +6,118 @@ 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() +======== -is_php() determines of the PHP version being used is greater than the -supplied version_number. +.. php:function:: is_php($version = '5.3.0') -:: + :param string $version: Version number + :returns: bool - if (is_php('5.3.0')) +Determines of the PHP version being used is greater than the +supplied version number. + +Example:: + + if (is_php('5.3')) { - $str = quoted_printable_encode($str); + $str = quoted_printable_encode($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_really_writable() +==================== + +.. php:function:: is_really_writeable($file) + + :param string $file: File path + :returns: bool -is_writable() returns TRUE on Windows servers when you really can't +``is_writable()`` returns TRUE on Windows servers when you really can't write to the file as the OS reports to PHP as FALSE only if the -read-only attribute is marked. This function determines if a file is -actually writable by attempting to write to it first. Generally only -recommended on platforms where this information may be unreliable. +read-only attribute is marked. + +This function determines if a file is actually writable by attempting +to write to it first. Generally only recommended on platforms where +this information may be unreliable. -:: +Example:: if (is_really_writable('file.txt')) { - echo "I could write to this if I wanted to"; + echo "I could write to this if I wanted to"; } else { - echo "File is not writable"; + echo "File is not writable"; } -config_item('item_key') -========================= +config_item() +============= + +.. php:function:: config_item($key) + + :param string $key: Config item key + :returns: mixed + +The :doc:`Config Library <../libraries/config>` is the preferred way of +accessing configuration information, however ``config_item()`` can be used +to retrieve single keys. See :doc:`Config Library <../libraries/config>` +documentation for more information. + +.. important:: This function only returns values set in your configuration + files. It does not take into account config values that are + dynamically set at runtime. + +show_error() +============ -The :doc:`Config library <../libraries/config>` is the preferred way of -accessing configuration information, however config_item() can be used -to retrieve single keys. See Config library documentation for more -information. +.. php:function:: show_error($message, $status_code, $heading = 'An Error Was Encountered') -show_error('message'), show_404('page'), log_message('level', 'message') -======================================================================== + :param mixed $message: Error message + :param int $status_code: HTTP Response status code + :param string $heading: Error page heading + :returns: void -These are each outlined on the :doc:`Error Handling <errors>` page. +This function calls ``CI_Exception::show_error()``. For more info, +please see the :doc:`Error Handling <errors>` documentation. -set_status_header(code, 'text'); -================================ +show_404() +========== + +.. php:function:: show_404($page = '', $log_error = TRUE) + + :param string $page: URI string + :param bool $log_error: Whether to log the error + :returns: void + +This function calls ``CI_Exception::show_404()``. For more info, +please see the :doc:`Error Handling <errors>` documentation. + +log_message() +============= + +.. php:function:: log_message($level = 'error', $message, $php_error = FALSE) + + :param string $level: Log level + :param string $message: Message to log + :param bool $php_error: Whether we're loggin a native PHP error message + :returns: void + +This function is an alias for ``CI_Log::write_log()``. For more info, +please see the :doc:`Error Handling <errors>` documentation. + +set_status_header() +=============================== + +.. php:function:: set_status_header($code, $text = '') + + :param int $code: HTTP Reponse status code + :param string $text: A custom message to set with the status code + :returns: void Permits you to manually set a server status header. Example:: @@ -67,15 +127,71 @@ Permits you to manually set a server status header. Example:: `See here <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html>`_ for a full list of headers. -remove_invisible_characters($str) -=================================== +remove_invisible_characters() +============================= + +.. php:function:: remove_invisible_characters($str, $url_encoded = TRUE) -This function prevents inserting null characters between ascii + :param string $str: Input string + :param bool $url_encoded: Whether to remove URL-encoded characters as well + :returns: string + +This function prevents inserting NULL characters between ASCII characters, like Java\\0script. -html_escape($mixed) -==================== +Example:: + + remove_invisible_characters('Java\\0script'); + // Returns: 'Javascript' + +html_escape() +============= + +.. php:function:: html_escape($var) + + :param mixed $var: Variable to escape + (string or array) + :returns: mixed + +This function acts as an alias for PHP's native ``htmlspecialchars()`` +function, with the advantage of being able to accept an array of strings. + +It is useful in preventing Cross Site Scripting (XSS). + +get_mimes() +=========== + +.. php:function:: get_mimes() + + :returns: array + +This function returns a *reference* to the MIMEs array from +*application/config/mimes.php*. + +is_https() +========== + +.. php:function:: is_https() + + :returns: bool + +Returns TRUE if a secure (HTTPS) connection is used and FALSE +in any other case (including non-HTTP requests). + +function_usable() +================= + +.. php:function:: function_usable($function_name) + + :param string $function_name: Function name + :returns: bool + +Returns TRUE if a function exists and is usable, FALSE otherwise. + +This function runs a ``function_exists()`` check and if the +`Suhosin extension <http://www.hardened-php.net/suhosin/>` is loaded, +checks if it doesn't disable the function being checked. -This function provides short cut for htmlspecialchars() function. It -accepts string and array. To prevent Cross Site Scripting (XSS), it is -very useful. +It is useful if you want to check for the availability of functions +such as ``eval()`` and ``exec()``, which are dangerous and might be +disabled on servers with highly restrictive security policies.
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