A TUTORIAL ON POINTERS AND ARRAYS IN C

      One of those things beginners in C find difficult is the concept of pointers. The purpose of this tutorial is to provide an introduction to pointers and their use to these beginners.

 

Standard Input and Output Redirection

              The shell and many UNIX commands take their input from standard input (stdin), write output to standard output (stdout), and write error output to standard error (stderr). By default, standard input is connected to the terminal keyboard and standard output and error to the terminal screen.
 

Open Diameter Software Architecture

              This document describes the software architecture used by Open Diameter for implementing the diameter base protocol library. It is designed to be modular, thread safe and scalable.
 

H.323 versus SIP: A Comparison

                                                             Provided with permission from Packetizer.

            This is, frankly, the best comparison of H.323 and SIP available anywhere. Virtually all of the others are misleading, out-of-date, and just plain wrong. To compound the problem--to further propagate the error, as it were--we have also seen several papers written by naive students and rank-and-file engineers that blindly parrot what they have read in these comparisons. Furthermore, many, many people have formed their opinions of H.323 and SIP based not on each protocol's merits but solely on the misinformation provided by these comparisons and through other information provided by largely the same sources.

To counter this misinformation, we decided to put together this thorough, up-to-date comparison. As with ours, please consider the financial interests of the source of any information on this subject, be it an author, speaker, institution, forum, company, web site, or conference. Are the people providing information on this issue involved in both of these--and other--protocols and have nothing besides perhaps an honest academic interest in one or the other protocol, or have they otherwise "hitched their wagon" to one?

Writing and debugging scripts

After going through this chapter, you will be able to:
      ♦ Write a simple script
      ♦ Define the shell type that should execute the script
      ♦ Put comments in a script
      ♦ Change permissions on a script
      ♦ Execute and debug a script

Bash and Bash scripts

In this introduction module we
      ♦ Describe some common shells
      ♦ Point out GNU Bash advantages and features
      ♦ Describe the shell's building blocks
      ♦ Discuss Bash initialization files
      ♦ See how the shell executes commands
      ♦ Look into some simple script examples

Protecting Files and Directories in Linux

              One important aspect of securing the host is to protect important system files — and the directories that contain these files. You can protect the files through the file ownership and through the permission settings that control who can read, write, or (in case of executable programs) execute the file.