PHP & User Login Authentication
PHP can be used to check if login fields match in a database. Built in functions allow advanced
methods of user authentication to be
used. A simple example of a user login authentication script
consists of 4 main parts.
The first part is retrieving the posted variables and assigning
them names descriptive of their values. The next part is
confirming the variables aren't empty. Then search the database
for matching login name, and running password comparison checks
if the name is found. Depending on the validity of the username
and password, three different pages can be dynamically rendered
to the user. One is a successful login, another is a page saying
username/password incorrect, and the last one saying username
not found and offering them a link to create an account.