Saturday, October 08, 2011

Port Perl scripts from Solaris to Linux

Although the Perl language is portable among platforms, most of the scripts used for system administration leverage platform-specific resources. And scripts meant for Solaris might use Solaris-specific pathnames and system commands that may have not equivalents on Linux®. This article gives you a roadmap for code remediation to help you port a Perl script from Solaris to Linux when direct mapping isn't available.

Learn Linux - Boot the system

Learn to guide your Linux system through the boot process. You can use the material in this article to study for the LPI 101 exam for Linux system administrator certification, or just to learn about the boot process.

Friday, March 27, 2009

Fixing Unix/Linux/POSIX Filenames

Traditionally, Unix/Linux/POSIX filenames can be almost any sequence of bytes, and their meaning is unassigned. The only real rules are that "/" is always the directory separator, and that filenames can't contain byte 0 (because this is the terminator). Although this is flexible, this creates many unnecessary problems. In particular, this lack of limitations makes it unnecessarily difficult to write correct programs (enabling many security flaws), makes it impossible to consistently and accurately display filenames, causes portability problems, and confuses users. more....

Monday, January 19, 2009

Linux Networking

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.

Hardening the Linux server

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.

Saturday, January 03, 2009

Booting Debian in 14 seconds

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.

Linux process management

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...

Wednesday, December 31, 2008

FreeBSD - Mounting Other Filesystems

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...

Perl : Creating Sets Using Bit Vectors

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...

Perl's Sort Function

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...

Saturday, December 27, 2008

Displaying maps with OpenLayers

Google Maps gives you a quick and easy way to add maps to your Web site, but when you're using Google's API, your ability to display other data is limited. If you have your own data you want to display, or data from sources other than Google, OpenLayers, an open source JavaScript library, can give you more options. read more...

Friday, December 26, 2008

CentOS Logical Volume Backup

Metadata backups and archives are automatically created on every volume group and logical volume configuration change unless disabled in the lvm.conf file. By default, the metadata backup is stored in the /etc/lvm/backup file and the metadata archives are stored in the /etc/lvm/archive file.. more