CodeIgniter 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.
|Returns:||TRUE if the running PHP version is at least the one specified or FALSE if not|
Determines if the PHP version being used is greater than the supplied version number.
$str = quoted_printable_encode($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.
|Returns:||TRUE if the path is writable, FALSE if not|
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.
echo “I could write to this if I wanted to”;
echo “File is not writable”;
|Returns:||Configuration key value or NULL if not found|
The Config Library is the preferred way of accessing configuration information, however config_item() can be used to retrieve single keys.
set_status_header($code[, $text = ”])
Permits you to manually set a server status header. Example:
// Sets the header as: Unauthorized
remove_invisible_characters($str[, $url_encoded = TRUE])
|Returns:||HTML escaped string(s)|
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).
|Returns:||An associative array of file types|
This function returns a reference to the MIMEs array from application/config/mimes.php.
|Returns:||TRUE if currently using HTTP-over-SSL, FALSE if not|
Returns TRUE if a secure (HTTPS) connection is used and FALSE in any other case (including non-HTTP requests).
|Returns:||TRUE if currently running under CLI, FALSE otherwise|
Returns TRUE if the application is run through the command line and FALSE if not.
Note : This function checks both if the PHP_SAPI value is ‘cli’ or if the STDIN constant is defined.
|Returns:||TRUE if the function can be used, FALSE if not|
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.
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.
Note : This function was introduced because Suhosin terminated script execution, but this turned out to be a bug. A fix has been available for some time (version 0.9.34), but is unfortunately not released yet.