Unix News

This tutorial covers TCP/IP networking and system configuration basics. Linux can support multiple network devices. The device names are numbered and begin at zero and count upwards. For example, a computer running two ethernet cards will have two devices labeled /dev/eth0 and /dev/eth1. Linux network configuration, management, monitoring and system tools are covered in this tutorial.

Servers—whether used for testing or production—are primary targets for attackers. By taking the proper steps, you can turn a vulnerable box into a hardened server and help thwart outside attackers. Learn how to secure SSH sessions, configure firewall rules, and set up intrusion detection to alert you to any possible attacks on your GNU/Linux® server. Once you've gained a solid foundation in the basics of securing your server, you can build on this knowledge to further harden your systems.

This article assumes that you're already familiar with things like building kernels, applying patches and so on. The target audience is the "advanced end user", and also the Debian developers responsible for the packages concerned who I hope will be motivated to incorporate some of this work.

The creation and management of user-space processes in Linux® have many principles in common with UNIX® but also include several unique optimizations specific to Linux. Here, review the life cycle of Linux processes and explore the kernel internals for user process creation, memory management, scheduling, and death. more ...

Anyone who has ever worked in a networked environment running different operating systems using different filesystems knows the frustration of trying to get every computer to see the data on every other computer. Even on my multi-boot test computer, NT can't see the data on my FAT32 partition, Windows 98 can't see the data on my NTFS partition, DOS can't see data on either partition -- and these operating systems are all installed on the same hard drive. more ...

To use bit vectors as sets we must enumerate the set members because all vectors have an inherent ordering. While performing the set operations, we won't consider the "names" of the members, but just their numbers, which refer to their bit positions in the bit vectors. more ...

Under the hood, Perl's sort() function uses the quicksort algorithm, which we'll describe later in the chapter. This is a standard sorting algorithm, provided by most operating systems as qsort(3).* In Versions 5.004_05 and higher, Perl uses its own quicksort implementation instead of the one provided by the operating system. more ...