A is for at

The at command is your willing and punctual servant for odd jobs, reminders and one-offs. A more footloose sibling of steadfast cron, at is used to schedule a task to run once at a given time. Then all is forgotten. The following examples and file paths are true for Red Hat Linux, and more or […]

B is for bash

Bash is a huge subject! The purpose of this article is demonstrate & explain some of the basics so you can write shell scripts and work at the command line more effectively. See also our article on Aliases and Functions in bash for ways to customize your environment. I recommend highly the bash man page!!! […]

C is for ch ch ch changes….

C is an extremely useful letter of the alphabet in Linux, especially when paired with an h. With these letters one can chown, chmod, chroot, and change lots of other things. One can even chkconfig. ***************************** chown – change ownership of a file. ***************************** Nothing too exciting to report here, but there are a couple […]

D is for df, du, dd

These three classic Unix utilities like to get their hands dirty with file systems. **************************************************** df – display disk space usage on mounted filesystems **************************************************** Every newbie sysadmin learns df right off the bat; it displays mounted file systems and the disk space usage on each. By default (in linux) it displays the statistics as […]

E is for Ext3fs Part 1

The ext3 filesystem now installs as the default file system in most Linux distributions. Essentially ext2 with journaling, ext3 retains the stability and robustness of ext2 while adding the much needed journal for high-availability. Part 1 of this article will discuss some filesystem basics and Part 2, some tips for working with the Linux native […]

E is for Ext3fs Part 2

In Part 1 of this article, we discussed some basics of the ext* filesystems in Linux. In this section we’ll have some good old filesystem fun. The most commonly used tools for working with Linux filesystems are mke2fs (create ext2/ext3 filesystem), tune2fs (adjust filesystem parameters) and e2fsck (check and repair filesystem.) ADD JOURNAL TO EXT2 […]

F is for Find

One-liners illustrating the use of the find command abound on the world wide web. The command’s operation is straight forward, but it has so many options that the man page always makes for fascinating reading. The find command is your friend whenever you need to *find* files based on name, size, file type, creation/access/modification time, […]

G is for grep

Like using the word “grok” in conversation, saying “grep” out loud brands you a SuperGeek, at least in the mundane reckoning of members of the “normal” population. They don’t understand that grep is simply an odd concatenation of the phrase “grab regular expression”; and even if they did know, it would mean nothing to them. […]

H is for Head, Tail, or Split the Difference

Head, tail and split are three of the most commonly used utilities on GNU/Linux systems for the manipulation of text files. They are tiny, sharp, and all possess some handy options of which even the experienced user may be unaware. Head returns the first lines of a file or standard input. By default, it outputs […]