PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

528 Chapter 24 Other Useful Features
Getting Information About the PHP
Environment
A number of functions can be used to find out information about how PHP is configured.
Finding Out What Extensions Are Loaded
You can easily see what function sets are available and what functions are available in
each of those sets by using the get_loaded_extensions() and
get_extension_funcs() functions.
The get_loaded_extensions() function returns an array of all the function sets currently
available to PHP. Given the name of a particular function set or extension,
get_extension_funcs() returns an array of the functions in that set.
The script in Listing 24.1 lists all the extension functions available to your PHP
installation by using these two functions.
Listing 24.1 list_functions.php— Lists the Extensions Available to PHP and the
Functions for Each Extension
Note that the get_loaded_extensions() function doesn’t take any parameters, and the
get_extension_funcs() function takes the name of the extension as its only parameter.
This information can be helpful if you are trying to tell whether you have successfully
installed an extension or if you are trying to write portable code that generates useful
diagnostic messages when installing.