Sams Teach Yourself PHP in 24 Hours, Third Edition

Importing User Input into Global Scope

It is possible, but not recommended, to import fields from a form submission into global variables. This behavior was once the default for PHP. Although it was useful for quick scripts, it represented a security risk, with the prospect of user-submitted values overwriting script variables. You can change the new default by altering the php.ini file. You can also import user input explicitly with the import_request_variables() function. This function requires a string representing the types to import and another optional but advisable string that adds a prefix to all imported variable names. The types argument can be any combination of g, p and c, standing for get, post, and cookies, respectively. If you ...