Sunday, June 29, 2008

The fork() function.

The fork() function is available on all UNIX versions of Perl, as well as the VMS and OS/2 ports. Version 5.6 of Perl support fork() on Microsoft windows platforms, but not unfortunately on Macintosh.read more...

Saturday, June 28, 2008

Debugging Perl

The standard Perl distribution comes with a debugger, although it's really just another Perl program, perl5db.pl. Since it is just a program, I can use it as the basis for writing my own debuggers to suit my needs, or I can use the interface perl5db.pl provides to configure its actions. That's just the beginning, though. read more...

Thursday, June 26, 2008

It's all about the inode - how the UNIX file system manages files

Have you ever wondered what Iused and %Iused mean in UNIX® commands like df or what people are talking about when the say inode? UNIX and Linux® systems both use inodes, and IBM® AIX® is no different. Discover what an inode is and why inodes are important to UNIX, the structure of an inode, and commands for working with inodes.

Wednesday, June 25, 2008

Arrays and hashes only with references

Always when you want hash, use curly brackets {}, always if array - square brackets []. And on one nesting level treat everything as list of scalars, nothing more, nothing less, read more...

Sunday, June 22, 2008

Bash Arrays

If you're used to a "standard" *NIX shell you may not be familiar with bash's array feature. Although not as powerful as similar constructs in the P languages (Perl, Python, and PHP) and others, they are often quite useful. read more...

Saturday, June 21, 2008

Linux - Printing with CUPS

The Common Unix Printing System (CUPS) is a modern printing subsystem for Linux and Unix that replaces the hoary old Unix line-printer protocols. It runs on Unix, Linux, Mac OS, and Mac OS X, and it serves clients on nearly any platform, including Windows. more...

Network profiles for a laptop

This article explains how to configure networking in a very pleasant way, so that it works automatically wherever you go. It is adaptable to lots of uses, and may be usefull even if you don't use Wifi but connect to multiple networks. This solution has been inspired by a tutorial that can be found in the references section at the bottom of this page. It uses three tools that integrate well with the debian network configuration:

Wednesday, June 18, 2008

Perl - Pair Programming

The last planning activity in XP is pair programming. Two programmers discuss what they are about to program. They write a unit test which is a formal specification. Only after their intention has been communicated to each other, do they begin the implementation. more..

Saturday, June 14, 2008

Perl PIPES

Network programming is all about interprocess communications (IPC), One process exchanges data with another. Depending on the application, the two processes may be running on the same machine, may be running on two machines on the same segment of a local area network, more...

Perl Sorting Techniques

Sorting is a commonly needed operation in all kinds of programs. Luckily, for us perl programmers, perl provides a very simple yet extremely powerful mechanism to accomplish any sort you might think of. This article is about teaching the novice programmer how to sort lists of things, while showing to the more experienced folks certain techniques and ideas that could be new to them if they are migrating from a different language.

Thursday, June 12, 2008

Object Databases

While the methods we've seen in the previous section work very well for storing and retrieving individual objects, there are times when we want to deal with a massive collection of data with the same degree of efficiency. more...

Sunday, June 08, 2008

Caches, thrashes and smashes

Even as George Gilder promises the world that bandwidth will be infinite, demand for network capacity seems to increase faster than corporate networks can deliver it. Wire speed may be cheap, but running a fat and wide pipe to every user's desk is typically beyond the financial reach of most IT organizations. Network congestion and server pile-ups haven't slaked our thirst for networked data access (possibly why we've devoted the last quarter's worth of columns to NFS-related topics).. more..

Saturday, June 07, 2008

Calculate network with Ipcalc

Ipcalc is a simple tool to calculate network, broadcast, netmask, etc. from an IP address. It also gives the class of the IP. It might facilitate the work of network admins. read more..

Kernel Basics

The kernel is a program that is loaded from disk into RAM when the computer is first turned on. It always stays in RAM, and runs until the system is turned off (or crashes). Although it's mostly written in C, some parts of the kernel were written in assembly language for efficiency reasons. User programs make use of the kernel via the system call interface, more...

Tuesday, June 03, 2008

Make An Iterator

The purpose of this tutorial is to give a general overview of what an iterator is, why they are useful, how to build one, and things to consider to avoid common pitfalls. It is intended to give the reader enough information to begin using iterators though a certain level of understanding is assumed. The See Also section should be researched if supplemental information is needed.

Sunday, June 01, 2008

smb.conf Setup

Because Samba is supplied on the Red Hat Linux CD-ROM, we'll walk through a simple Samba setup using Red Hat Linux. When installing Red Hat Linux, you can select the software packages you want to load, as you can on most all UNIX variants. If you did not load Samba at the time you originally loaded the operating system, you can use a graphical RPM tool or rpm from the command line to load Samba or any other software. These tools were briefly discussed in the Chapter 10 covering System Administration.

uptime