Setting the timezone on CentOS. This is going to take me longer to write this article up than actually showing you how to accomplish this. This is pretty much a fairly simple operation. There are loads of timezone data files stored in:

/usr/share/zoneinfo

I have seen many people explain this many ways. There are system commands to run, they are scripts, but by far the simplest way I know of is to just the replace the symbolic link located at:

/usr/share/zoneinfo

So for my CentOS install, to set my machine to London time, I use:

$ date
Thu May  6 11:50:07 EDT 2010
$ sudo rm /etc/localtime
$ sudo ln -s /usr/share/zoneinfo/Ameica/Chicago /etc/localtime

Now check it’s the timezone you expect. You may to dig around to find the correct timezone but you get the point.

 date
Thu May  6 11:50:33 CDT 2010

I imagine this works on Redhat and Fedora as well, but I can’t be sure on other Linux distros.

Enjoy and Have a Good’n!

Today I am going to step back a little bit and cover a subject that seems to be a pivotal make it or break it moment in most would be Linus users. For those of us who are long past the transition days between M$ and Linux, can still remember the day we found out that the Linux shell (a.k.a The Terminal) is where we would spend most of our time trying to customize our Linux distro, or in some cases trying to get our favorite distro working. Anyway I understand that in this day and time Linux is getting better about meeting the needs or the graphical point and click user, but still by far the shell is the most powerful tool in any Linux users arsenal.

So lets get started!

Shells

The Shell is also known as the command line for those new to Linux, and the shell is also used to execute your commands (sometimes without you even knowing it). Common examples include tcsh, bash, zsh, ksh, ash,…. However, there are two main styles: Korn Shells (bash is the main one) and C Shells (tcsh is the main one). A note about Windows shells; they suck, do not work properly, and do very little expect execute commands. Now on the contrast *nix shells are full programming environments with your imagination as the limit. Shells read your commands, interpret them and execute system process.
If the command is a built-in (eg cd skoleLinux), your shell does it internally. Otherwise, it searches the PATH environment variable for a program matching with that name. Here’s my PATH (and how to display it):

The difference between one shell and another lies mostly in the details of the interpretation and what built-in commands are available. The shells are the main owners/maintainers of Environment variables (eg $PATH, $CVS_RSH, $UID). One major difference between bash and tcsh is the built-in command used to set/modify your environment variables.

In bash, to set an environment variable you do things like:

export PATH=/usr/local/bin:/usr/bin
export PATH=$PATH:/usr/bin/X11:/usr/games:/<a class="zem_slink" href="http://en.wikipedia.org/wiki/Home_directory" title="Home directory" rel="wikipedia">home</a>/asanford/bin
echo $PATH
        /usr/local/bin:/bin:/usr/bin/X11:/usr/games:/home/asanford/bin

In tcsh, you would do:

setenv PATH /usr/local/bin:/usr/bin
setenv PATH $PATH:/usr/bin/X11:/usr/games:/home/asanford/bin
echo $PATH
        /usr/local/bin:/bin:/usr/bin/X11:/usr/games:/home/asanford/bin

I recommend using bash. It’s the standard shell in almost any modern day Linux installation, and it’s the one most people will generally assume you are using when trying to help you out.

BASH

A few useful facts about bash:

1. ~/.bash_profile (ie the file .bash_profile in your home dir)

All commands in this file are executed when you start bash. So you can put customizations in there, such as setting environment variables. You might like to create the file with:

              export CVS_RSH=ssh
              export CVS_ROOT=":ext:asanford@cvs.example.com:/var/lib/cvs"

the above commands would be executed every time you login. Then you wouldn’t need to type the commands every time you want to use CVS, they’d be set every time in advance.
2. alias

If you type a command a lot (eg ssh -X -C asanford@example.com): you can create a shortcut by:

      alias forty="ssh -t -X -C asanford@example.com "

so, from then on, every time you type “forty” on the command line, when bash interprets it, it will substitute the above longer string delaying your inevitable arthritis. This is something you would put in your ~/.bash_profile
3. It’s a full programming environment.

Without going into gory details, it will suffice to say that you can write if, else, while, for, … etc. directly into bash and it will interpret it. For example, the following command will loop over a bunch of infidel usernames, deleting their home directories.

         for i in asanford ksanford john
         do
              rm -r ~$i/
         done

4. Wildcards and other special characters

If you do

              ls foo_*.txt

you’ll get a listing of all files beginning with “foo_” and ending “.txt” . In DOS, you can similarly do

      dir *

. However, in DOS, the dir program reads the * and evaluates it. Here, BASH evaluates the * and ls sees the list of files as its options. `ls` itself does not understand wildcards. When it interpets the command it looks for certain special characters to interpret:

* means a sequence of one or more characters (a wildcard)
? means a single character (a wildcard)
$ means the following characters make up an env variable (eg $PATH)
[acde] means a single character matching any of a,c,d or e
[0-9] means any digit
~ shorthand for home directory

As a case in point, if you are ever in a directory with a huge number of files (say 100,000) and you want to delete or list the files, you might try:

          asanford@shual$ rm *
          bash: /bin/rm: Argument list too long

It won’t work. This is because bash evaluates the *, all 100,000 filenames end up as arguments (options) to the command and `rm` can’t handle this. One solution is as follows explaining this in detail is outside the scope of this document but trust me it works:

          asanford@shual$ ls . | gawk '{print "rm -f "$1}' | bash

So bash launches the rm command once for each file * matches instead of once for all files.

The Basics

You may have noticed that each time you start Xwindows, a shell window, similar to a DOS window in Win95/98, appears. This is the powerhouse of the Linux OS, and from here you can execute copy, compile, move, find and edit commands just as easily as in dos. Unfortunately, there are different commands used in the Linux shell than in DOS, so I’ll explain a few of them. Remember that commands are case sensitive in Linux, so LS is not the same command as ls, and will return an error.

Changing Directories – You’ll need this more often than anything.

Just as in DOS, the cd (Change Directory) command is used. When the command shell opens, it opens in your own (Most of the time there are some exceptions), home directory. If you ever need to return to your own home directory, just enter cd and press return. As in DOS, to move out one level in a directory tree, type cd .. You can go to the root directory of your Linux OS and all it’s drives by typing cd /. Note how in Linux, there is a backslash instead of a forward slash. Another thing is that Hard Disks are not mounted as drive c, drive d and so on. They are placed as folders, and to all intents and purposes look just like one big hard disk. To find out what disks are mounted, where, and what capacity they are and have left, type df (I remember this using, disk free, relating to free space). If you want to go to one of the user accounts on your machine, you can cd ~username, and that’ll take you to where their account resides (Assuming you have permission to enter their directory).

Need to know what is in a directory?

DOS has that crappy dir command, but where is the Linux version? It’s replaced by ls. ls, can be remembered as a list (Acronym) of what is in that directory. It is quite confusing to look at, and its harder to separate what is a folder, what is a file, and what can be run. In DOS, there are a vast number of switched, or options, that can be added to the basic command dir to give more information. Linux is not left behind, and adds even more commands to confuse yourself with *grin*. ls -m (remember this as more), is similar to dir /w, giving horizontal lines of filenames and directory names. ls -l is a switch that will give the full names of the files, and then give the permissions of the files (Who is entitiled to execute them), and whether or not they are executable. If an X is present in the attributes, that file is a program, and can be run by typing ./nameoffile. Files can only be run if they have the ./ prefix before them. The other attributes you will learn as time progresses and you become more familiar with the Operating System. The best usage of ls, is ls –color. This gives a wide listing, with colors assigned to various file types. When using this option, directories are in blue, and executables in green. This option is by far the best. Typing ls –color can get annoying as I found after a while, so its possible to create a text file with ‘ls –color’ contained, and then allow that file to be executed. By placing this file in the path, and changing its name to lss, you could use it quite frequently! I will show how to do this at a later date.

File name completion

Ok now the nicest features about a Linux shell, as opposed to the DOS shell, is that it can (if configured to do so and most distros do by default) complete file names and directory names for you. The TAB button, located above Caps-Lock, is the completion key. Once you have typed in the beginning of a file, or directory, pressing TAB will search for a list of possible file or directory names. If more than one option is presented, nothing will appear, you will most likely get some sort ot audible bell or screen flicker, and pressing TAB a second time will present a complete listing of all the available completion candidates, enter a few more characters of the option you want, and press TAB again.

Copying files

This is an interesting one. For copying internally between mounted drives, it’s very similar to the DOS syntax. to copy blah.xxx from the current directory to /root/, the syntax is cp blah.xxx /root/, just remember that if something is going into a lower level directory to give the full path, including the forward slash.
Moving or Renaming Files

Again, ths syntax is very similar to the DOS syntax. If you want to rename blah.xxx to xxx.blah, the command is mv blah.xxx xxx.blah, fairly simple. If you are just relocating the file, remember that two files with the same name cannot reside in the same directory, so you will have to give a directory name, just like the description in the Copying section above.
Working with MS-DOS floppy disks

Now one of the most useful things to now is how to wiping the screen clean and have the first line at the top of the screen or window. To clear a screen full of text, just type in `clear` from the command line

Any way I hope this has been a helpful introduction for someone out there.

Enjoy and Have a Good’n!

Each menu option will allow you to open an SSH session in a new terminal window. You can organize the connections into groups of hosts using separator bars or sub-menus. You can even open all the connections on a submenu (in separate windows or tabs) with one click.

Here’s a killer feature found in SSHMenu , imagine you just connected to a production server and the terminal window had a red-tinted background, to remind you to tread carefully, well using terminal profiles, SSHMenu allows you to specify colours, fonts, transparency and a variety of other settings on a per-connection basis. You can even set window size and position, talk about convenient.

The latest source distribution can be downloaded from here, but you’ll probably want to get a pre-built package for your platform if possible.

If you’re running Debian, Ubuntu, etc … you can install the packages directly from the repository locate here. Downloading from these repositories will ensure that the Ruby and GTK dependencies are resolved automatically.

There are manual installation instructions that describe all the files in the distribution and where you need to put them on your system to make them work. This information is really targeted at people who wish to build packages for other OS distributions.

For more information setting up SSHMenu you can visit this page http://sshmenu.sourceforge.net/setup/

Enjoy and Have a Good’n!

grep -i name /proc/bus/input/devices
lshal | grep Aiptek

The following information is for installing aiptek-based USB tablets for Linux and X11, not to be confused with the older serial-based hyper pen module. This tablet is also known as a Dolphin, Medion (Aldi tablet), Nisis and a few other generic brands.

The xserver-xorg-input-aiptek package must be installed to use this tablet, this is where I ran into my biggest troubles. I keep trying to install wizardpen drivers because all my searches for Ubuntu and DigiPro were leading me to results that linked to wizardpen drivers instructions, hence why I am writing this. To install run the following command.

sudo apt-get install xserver-xorg-input-aiptek

Support for the Aiptek tablet has improved a tremendous amount in a short time since Ubuntu 8.04. One of the more confusing things is setting the correct configuration setup for HAL. The settings for the tablet are now stored with HAL, and no longer requires one to have to edit the xorg.conf file. The following will fix you up; create a file named 10-aiptek.fdi, in the directory /etc/hal/fdi/policy with the following content (make note if your tablet has 1024 levels of pressure sensitivity use 1023 instead of 511):

<?xml version="1.0" encoding="UTF-8"?> 
<deviceinfo version="0.2">
  <device>
    <match key="info.product" contains="Aiptek">
      <merge key="input.x11_driver" type="string">aiptek</merge>
      <merge key="input.x11_options.SendCoreEvents" type="string">true </merge>
      <merge key="input.x11_options.USB" type="string">On</merge>
      <merge key="input.x11_options.Type" type="string">stylus</merge>
      <merge key="input.x11_options.Mode" type="string">absolute</merge>
      <merge key="input.x11_options.zMin" type="string">0</merge>
      <merge key="input.x11_options.zMax" type="string">511</merge>
      <merge key="input.x11_options.KeepShape" type="string">On</merge>
    </match>
  </device>
</deviceinfo>

All you need to do now is to restart udev and xorg or for simplicity just reboot, for newbies I recommend rebooting just to be safe.

Now most people will be using their tablets to draw in GIMP but almost everyone will notice that if they try and use it now the 512/1024 pressure sensitive feature will not be working, not to worry this is a GIMP configuration problem. To configure GIMP to use the pressure sensitive feature navigate here in the menus Edit >> Preferences >> Input Devices >> Configure Extended Input Devices … Now you need set the mode to either window or screen I screen but the choice is yours. Save your settings and restart GIMP for good measure and off you go.

Some tablets (6000U, 12000U, 14000U) seems to use Wacom drivers, if you experience problems with button presses (Your mouse pointer freezes), but you can move the cursor try the updated packets for Wacom.

(I think I’ll write a review on this tablet too I like it a lot)

Enjoy and Have a Good’n!

    sudo vim /etc/apt/sources.list

    ## main & restricted repositories
    deb http://us.archive.ubuntu.com/ubuntu/ jaunty main restricted
    deb-src http://us.archive.ubuntu.com/ubuntu/ jaunty main restricted
 
    deb http://security.ubuntu.com/ubuntu jaunty-security main restricted
    deb-src http://security.ubuntu.com/ubuntu jaunty-security main restricted
 
    ## universe repositories
    deb http://us.archive.ubuntu.com/ubuntu/ jaunty universe
    deb-src http://us.archive.ubuntu.com/ubuntu/ jaunty universe
    deb http://us.archive.ubuntu.com/ubuntu/ jaunty-updates universe
    deb-src http://us.archive.ubuntu.com/ubuntu/ jaunty-updates universe
 
    deb http://security.ubuntu.com/ubuntu jaunty-security universe
    deb-src http://security.ubuntu.com/ubuntu jaunty-security universe

Real quick here update apt-get!

    sudo apt-get update

Now we install the needed packages for our LAMP installation.

    sudo apt-get install apache2 php5 libapache2-mod-php5 mysql-server

Now the default location for your files will be located in /var/www/. If you were to put a file named index.php in the root folder /var/www/ it should render and display the rendered content, for some us however it will prompt us to download this file, or worse show the actual contents of the file, both cases not good. If you are one the later here, running the next set of commands will fix you right up.

    cd /etc/apache2/mods-available/
    sudo ln -s php5.conf ../mods-enabled
    sudo ln -s php5.load ../mods-enabled
    sudo /etc/init.d/apache2 force-reload

You should now have your LAMP installation running. Now you should read up on configuring each of the components but I will save that for another day.

Enjoy and Have a Good’n!

WINDOWS VS LINUX the song:HERE COME THE HOTSTTEPER.

This is an older video, but what a great one it is, that shows how far behind Microsoft is actually falling despite all the attempts to hide and/or deny it! Now, I am not going to go off on a tangent here just watch the video and be ready to be amazed. (If you are a Linux user this will come as no surprise!)

One problem you may or may not have considered is all your files and settings. Now I am not trying to talk you out of moving to Linux just making you aware of troubles you will be facing when trying to migrate over. If you opt to re-size your Windows partition and install Ubuntu in a dual boot environment, the Ubuntu installer will prompt you to transfer your files and settings over from your Windows installation. If you are going to opt to obliterate Windows all together you will want to back up your files and settings before you begin (I would back up my files in either case). Make sure you back up your Internet Explorer bookmarks or FireFox bookmarks or both as the case may apply to you. Ubuntu will be able to read from (and even write to) Windows partitions, so copying files from a Windows partition to your new Ubuntu file system is possible. So if you are just choosing to use a new Hard drive then you will not need to back up your data before hand. If those files are on a server (shared), you can get to them via smb (included by default in e.g. Ubuntu’s nautilus file browser). In this case, you will have to log on to that server with a user account known to that server, and with the necessary permissions to at least copy files and directories, but that’s easy to set up.

OpenOffice will open MS Office documents, spreadsheets and presentations, Visio and MS Projects clones work towards compatibility with files created with the Microsoft products, pdf’s are not problem, Adobe even releases a Linux version, … But your mileage may vary as so things still don’t port but this will be the exception I promise.

If you were already using Firefox on Windows, this is going to be pretty straightforward. We already know we can copy between the two file systems, and Firefox keeps all settings inside a user profile so moving thins around will be easy. If you are using IE I suggest you install FireFox right now and then import your IE bookmarks to FireFox and then continue this will make life so much easier for you.

As for the rest of your media you will just need to copy things over and then learn the new applications you are going to use to read, listen, or view them. Pretty straightforward here.

OK, lets get our hands dirty, The first thing you need to do is print this article out so you can have it own hand or at the very least write down the URL or bookmark before you begin installing Ubuntu. You should have already downloaded Ubuntu 9.04 and burned it to a CD, if not you need to do so now here is a link if you need it, for those not sure you need the Desktop version. OK, go ahead and install Ubuntu. If you need help with that here is a link.

So you have Ubuntu installed now this is where I enter with some very useful information that is missing in most manuals when you switch to Linux. The reason most install guide leave you here is because Linux is about choice, and they expecet you to make your own choices, but what about the simple everyday things we use our computers for. Media, mail, and the Web (This is where flash and Java come in). They are most likely not working at this point an most Linux distro and there is of coarse a reason for that as well. Now, I am not going to dive to deep into the legalities of why codecs are missing and things don’t quite work but just understand that there are legal ramification for the maintainers and they have to watch out for their own interests.

OK, So I am going to give you a little bash script here to run from the command line.  This should get your Shinny New Ubuntu running with all the restricted stuff installed, Flash Working as well as Java.

#!/bin/bash
sudo apt-get install flashplugin-nonfree ubuntu-restricted-extras w64codecs msttcorefonts sun-java6-jre sun-java6-plugin sun-java6-fonts
sudo fc-cache -fv

On the Windows XP system or in your backup files, look in your profile folder : …\Documents and Settings\%username%\Application Data\Mozilla\Firefox\Profiles\xxxx.default\, where xxxx is a random name. Copy this folder.

On the Ubuntu system, you will look in your $HOME for …/.mozilla/firefox/yyyy.default (where $HOME = /home/your_user_name and yyyyyyyy is another random name). Note that .mozilla is a hidden folder : if your copying in a file browser, you may have to tell it to show hidden files. Copy the XP Firefox profile (xxxx.default) to $HOME/.mozilla/firefox/xxxx.default, then change the Path in $HOME/.mozilla/firefox/profiles.ini to xxxx.default and delete yyy.default – or rename xxxx.default to yyyy.default. You get the idea : just replace the new Ubuntu profile with your old XP Firefox profile.

As for your email, if you are not using an online provider such as gmail, yahoo, or the like, then you will need to consult the documentation on how to migrate that information from windows to Linux and in some cases it will not be possible or extremely difficult. In the earlier case you will not have lost anything. In that later case worst case scenario you will have lost your old emails, configured you email client (Most likely Evolution), and will get future emails. There are several types of email accounts POP3, IMAP, and Exchange and this is all beyond the scope of this article.

Now if you move all your backed up data to your new Ubuntu box you should be good to go. Just go ahead and browse around the menus and you should find everything nicely labeled.

First you  will need to install the php mod for apache if you do not already have it installed

# sudo apt-get install libapache2-mod-php5

Now on your root web directory directory (for this tutorial we will assume the default /var/www/)

# sudo -u www-data vim /var/www/hello.php

And paste the following:

Now you can check the output by navigating to http://127.0.0.1/hellop.php or http://www..com/hello.php You should see in the browser window simply “Hello World!” If you see anything other than this stop and start over.

Next we will be installing the .NET module for apache2.

# sudo apt-get install libapache2-mod-mono mono-apache-server2

Now we don’t want to have to bother configuring apache manually to handle ASP.NET 1.0 or ASP.NET 2.0 lets just let the system decide for its self so we will run the following command.

# sudo a2dismod mod_mono; a2enmod mod_mono_auto

This next step may or may not apply to you but I am putting it in here for good measure because if the file does not exists you only get ASP.NET 1.0 support.

# sudo ln -s /usr/bin/mod-mono-server2 /usr/bin/mod-mono-server

Now lets run a test on the ASP stuff

# sudo -u www-data vim /var/www/hello.aspx

And paste the following:

<% HelloWorldLabel.Text = "Hello World!"; %>

# sudo apt-get remove dhcp3-client

Now this will also remove ubuntu-minimal but it want tear anything up it is what you want.

The next thing is to configure your  /etc/network/interfaces file

# sudo vim /etc/network/interfaces

Add something similar to the following (Of coarse these values will have to adjusted to fit your network):

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
        address 74.207.227.124
        netmask 255.255.255.0
        network 74.207.227.0
        broadcast 74.207.227.255
        gateway 74.207.227.1

Now all you have left to do is restart your networking like so.

# sudo /etc/init.d/networking restart