Posts in the “linux-unix” category

I know the vi editor (and vim editor) can be a little hard to get started with, so I've been trying to share some short vi tutorials lately. Today I'd like to share some simple vi insert commands.

vi insert commands - reference

If you're already comfortable with the vi editor and just need to know some commands to insert in vi, here are the vi insert commands I use every day:

vim FAQ: Can you recommend a good vim tutorial?

Need help learning how to use the vi or vim editor? How about an interactive vim tutorial? Wouldn't that be great?

Many people don't know it, but if you have the vim editor installed on your Unix or Linux system, you probably have a built in vim tutorial right there at the command line.

This page shows the contents of the Linux crontab man page that deals with the crontab file format (syntax), or as it says in the man page, "crontab - tables for driving cron". This crontab man page output was created on a CentOS Linux system.

You can see this same crontab man page output by entering this command on your own Linux system:

Unix/Linux processes FAQ: Can you share some examples of the Linux ps command? (Or, how do I use theps command?)

The basic Linux ps command

If you run the ps command by itself, it only shows very basic information about the processes you are currently running. For example, if you issue the basic command like this without any arguments:

ps

you'll see output from this command looks something like this:

Wow, I just learned about the Linux locate command the other day. I'm going to have to quit using find so much. The locate command is very quick, assuming it can find what it's looking for in it's cache.

Here's a quick locate example. Assume that you have apache installed on your system, but you can't remember where it is. Just type locate apachectl to find the apachectl command, and you'll see locate return some output, very quickly, like this:

How to see the permissions and size of a directory

Here's a short story :) on how to look at files and directories on a Unix/Linux computer system. I've seen so many people do this the hard way that I thought I should finally write something about it.

Here is the code I use to create a list of descriptions in LaTeX. In this example, I'm creating three descriptions that deal with the subject of Six Sigma. (My apologies to Greg Brue for the blatent copy/paste action here. I was just trying to find a simple example, and his book was the first I found.)

This is a collection of LaTeX example tags. I'm in the process of creating one super-LaTeX example file to show how to do many things with LaTeX that work with both pdflatex and latex2html, and this is part of that super-file.

In the example content below I'm showing:

This one may be my favorite LaTeX example yet. It shows how to create a table/grid, where the labels of the columns are rotated at a ninety degree angle, so they run straight up and down. This way, I can have very narrow columns, which is extremely helpful when trying to build a "house of quality" table for my current Six Sigma effort.

Without any further ado, here is the LaTeX code:

LaTeX PDF Example: Here's an example of how I learned to control line spacing in lists when creating PDF documents with LaTeX.

The reason I use this LaTeX PDF line spacing technique is that I'm writing some requirements specifications for software applications, and by default the LaTeX line spacing for lists and enumerations is too large. It appears that the items are double-spaced, and I really want them to be single-spaced.

Like everything else with LaTeX right now, I won't say that this is a perfect solution, but it does work very well.

I often use the Lynx character-based web browser, but can never remember or find their obscure commands. Two that I really need are how to create bookmarks, and how to access them.

To create a bookmark in Lynx, just go to the page that you want, then press the letter 'a'. When Lynx brings up a prompt, select the letter 'd' (for Document). That's all.

I don't know of any direct commands to do this, but this cat command works:

cat /etc/redhat-release

You can also take a look at the uname command, which can provide a lot of Linux version information.

A review of my Fujitsu T Series Lifebook Tablet PC

I've had a Fujitsu T Series Lifebook PC for about six months now. It's actually a Tablet PC, or more appropriately, a hybrid. That means that it can switch between being a small notebook computer and a "slate" model Tablet PC. It converts to a slate model by swiveling the monitor 180 degrees, and then folding it down onto the keypad (which is a very clever design).

Linux nohup FAQ: What is the Linux nohup command? Can you share an example of how it's used?

So you want to log off and go home for the night, but you need to run a job (process) on your Linux or Unix system that's going to take a couple of hours? Fear not, the Linux nohup command ("no hangup") will help you out.

I'm often asked how you can determine the amount of free memory (RAM) available on a Linux computer system. Here are two ways I know:

cat /proc/meminfo

or

free

Although I've written my own Perl program to extract lines from the middle of a file, I was just reminded that this can be done with the Linux sed command.

Here's a simple sed command example. Supposed you want to print lines 500 through 600 from a file named reallyBigFile.txt. Just issue this command and you'll get what you want:

sed -n '500,600p' reallyBigFile.txt

I had a problem using the tar command this morning while trying to create a large archive, and rather than figure out what in the world I was doing wrong with find, xargs, and tar, I decided to use pax instead. It worked great at creating an archive file that tar could still read, so instead of fighting with the find/xargs/tar three-headed monster to create a large archive, pax bailed me out.

Here are a couple of quick Linux tips I put together. First, a Perl CGI program that prints every environment variable it knows.

Second, a Unix/Linux tip that shows how to create multiple directories and subdirectories in one feel swoop.

Maybe because I'm a bit of an old-timer, or maybe because I like the speed, I often use mutt for my email. Knowing that, DD forwarded me this link of good mutt tips. As an old(er) friend might say, I'm all over that like green on a frog.

I don't know exactly how I'm supposed to be able to control the text that appears in the titlebar of a Command prompt window in Windows 2000 and Windows XP, but I've figured out something that kind of sort of works. Just follow these steps: