Introduction

The proc interface is a well-established and widely used interface in the Linux kernel; beginning with the late 0.99.X releases of the Linux kernel it has been part of the official kernel releases. First versions focused on network issues, but additional subsystems quickly began using proc files in order to simplify administrative and debug tasks. With the early releases the API was fairly complex, but as of Linux kernel 2.4.X, the API for the proc interface has become very user-friendly. The main feature of the proc file systems can be summarised as follows.

• Simple API,
• Direct access to kernel internals,
• Simple access via file system-abstraction,
• POSIX compliant open/ read/ write/ close interface,
• Kernel level security setting on a file-scope.

In this article an introduction to using the proc interface specifically for embedded an real-time Linux is given. This work is part of an on-going GPL project for Keymile AG Vienna, Austria, where the proc interface is applied to a series of embedded Linux based high-bandwidth Internet access devices.