Returns an associative array of option / argument pairs based on the options format specified in options, or FALSE on an error.
The options parameter may contain the following elements: individual characters, and characters followed by a colon to indicate an option argument is to follow. For example, an option string x recognizes an option -x, and an option string x: recognizes an option and argument -x argument. It does not matter if an argument has leading white space.
This function will return an array of option / argument pairs. If an option does not have an argument, the value will be set to FALSE.
Note: This function is not implemented on Windows platforms.