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The prevention of unauthorized access to computer systems. Authentication takes a variety of forms, ranging from verifying account credentials (using, amongst other things, a login name and password) to physical identity verification (using biometrics such as finger print scanning technology) to identifying that the client system from which a user is attempting to connect to a server is really the authorized client system. (more…)

These Javascript tutorials start with the very basics.In the following sessions on this tutorial, you will learn how to detect browsers, print current date and time on a web page, change images on mouse-over, display statements in the browser Status Bar and several other things.

Here are some examples of command-line tools written in PHP.

PHP Filter Utility
This example includes a little tool for filtering line
by line from standard input through a PHP function that returns a string: (more…)

In UNIX, signals are a basic mechanism to pass messages
between processes. They enable processes to tell each other that some type of
event has just occurred. This type of event is the only information passed to
basic UNIX signal handlers. There is another signal-handling mechanism
called “sigaction” in which signal handlers receive more information, but PHP
signals are based on the former, basic form. For example, if the user presses
Ctrl-c to stop a command-line program, the program receives an interrupt sig-
nal, called SIGINT. (more…)