Linux Blog

sl the BOFH’s revenge for bad typists

Filed under: Linux Software — TheLinuxBlog.com at 9:57 am on Wednesday, November 19, 2008

If you don’t know what BOFH is, then lets try wikipedia. This morning in my feed reader from tips4linux.com was an article that “makes you pay attention.”

Basically, the article software package they were recommending today is sl. I couldn’t resist commenting on this. There are many times that I am stuck over a slow SSH session, all I need is the server admin, or BOFH coming along, installing sl and making my life a pain.

So, I installed it on my desktop. What an excellent piece of software. If you run Fedora its in the yum repos and you should give it a shot. Now, all I have to do is symlink this to other useful binaries that I commonly mistype, don’t have installed and for good operator measures, some that I do.

Its too bad that I couldn’t run this through wall, but I guess I could run it as a cron. I think it should have a config file so that you could work it a bit more. Perhaps as it steams through make the smoke spell a message. Any way, thats my ranting and rambling over for the morning. Now to yum remove.

Forwarding Ports over an active SSH connection

Filed under: General Linux,Linux Software,Quick Linux Tutorials — TheLinuxBlog.com at 12:01 am on Tuesday, October 7, 2008

There is no doubt about it that SSH is a handy administration and remote access tool. Have you ever wanted to add port forwarding or cancel port forwarding from within an active SSH connection? Well, a feature that many do not know about is the ssh escape feature. With this pseudo terminal you can do some nifty things, such as forward ports over an active SSH connection.

To do this, follow these instructions:
(Read on …)

Office 2007 docx to ODF Conversion

Filed under: Linux Software — TheLinuxBlog.com at 10:38 pm on Monday, September 29, 2008

I was going to write an article on how to open docx’s and other Office 2007 documents but there are numerous articles out there explaining how to do this on many distributions. They all basically say the same thing, you download the file, extract it and put it in your open office directory. Normally there are a couple of files but the on we are interested in is the main binary. What some people don’t know is that if you want to just quickly open or convert a document you can do so by using the odfconverter binary. (Read on …)

Charting your boot processes with bootchart

Filed under: Linux Software,Quick Linux Tutorials — TheLinuxBlog.com at 4:57 pm on Monday, September 22, 2008

Linux users often like to boast about their awesome bootup times. I thought that there was nothing cooler than getting a wicked fast bootup time, until now. A while back I found this nifty application called bootchart and shoved it in my bookmarks. I was randomly surfing my bookmarks, came across it again and gave it another shot. (Read on …)

KDE End User Wiki

Filed under: Linux Software — TheLinuxBlog.com at 10:27 am on Friday, September 19, 2008

Today the KDE User base wiki (http://userbase.kde.org/) went live. If you’ve ever searched for information regarding an issue with KDE, its possible you would have come across the techbase (http://techbase.kde.org) The KDE Techbase is aimed more at developers and has some really good content regarding development. The KDE userbase Wiki also has some great information and you can learn a lot about KDE just by reading it. If you are a developer or an end user the userbase can be of great help, I just learned something new about plasma application launchers, check it out!

Using Subversion with SSH & Custom Ports

Filed under: Linux Software,Quick Linux Tutorials — TheLinuxBlog.com at 9:09 am on Monday, September 15, 2008

Lets say you use subversion on your home PC to keep track of projects and you want to checkout or export your project from a remote location. Here’s the catch, sshd is running on a custom port or forwarded from another. For some reason the command line SVN client does not support a port parameter when using the defacto svn+ssh://

svn co svn+ssh://thelinuxblog.com/owen/svn/project1/trunk project1
ssh: connect to host thelinuxblog.com port 22: Connection refused

Well we know why the error above happens its because I happen to run SSH on port 1337. The following work around requires root privileges, and may mess with your system a bit but if you really need to check something out, then it will work.

As root, login and stop SSH if you run it. With SSH Forward port 22 with a local SSH forwarding connection to the remote host.

[owen@thelinuxblog.com]$ sudo su -
[root@thelinuxblog.com]$ /sbin/service sshd stop
[root@thelinuxblog.com]$ ssh -p 1337 owen@thelinuxblog.com-L 22:[internal ip]:1337

Once this is done, your localhost:22 now forwards to your remote host. With another session (on your local machine) you can verify the connection by using ssh localhost. You will probably get warnings about the hosts identity being changed, or not verifying it, but you can ignore then. Once you’ve tested it, just use SVN as normal. When finished, remember to logout of the SSH session, and start SSH back up again if you run it.

Before you complain / ask about Java

Filed under: Linux Software — TheLinuxBlog.com at 8:44 am on Wednesday, August 27, 2008

Before you ask why your Java applications don’t work, or why your applet doesn’t initialize in Firefox, Seamonkey or Whatever browser you use do you know what version of Java you are using?

“Yes, I installed the JRE 1.6.0_XX”,

Thats nice, but is it running? Now, it may seem as obvious as “Is your computer on?”  to some, but to others and I admit myself it isn’t always that obvious. I had installed the Java Runtime /JDK and tested my firefox. Programs worked from the command line, java -version provided me the correct Java version, but why were my applets failing to load?

The firefox plugin is the answer. Open up about:plugins in firefox and take a look at the Java providers. If you don’t see the Java(TM) plugin there then there is a problem. Refer to the Correct Java documentation on how to get this corrected. Basically you symlink a file and disable the other Java providers.

What Read Times do you get on your hard disks?

Filed under: Linux Software — TheLinuxBlog.com at 11:20 pm on Saturday, August 23, 2008

Hard drives are a vital part of system performance. They really are one of the biggest bottle necks in computing. Its nice to know how many MB/s your hard drives are capable of reading. If you perform the tests could share your results with other Linux Blog readers? With advances in hard drive technology I hope to see performance get better, and already see a major increase in performance over the old IDE type drives.

To check your hard drive read times use hdparm like so:

hdparm -t /dev/sdX

replacing sdX with whatever device your distribution assigned. Here are my results:

sda is my internal 80GB SATA drive.
 
/dev/sda:
Timing buffered disk reads:  224 MB in  3.02 seconds =  74.07 MB/sec
 
sdb is an internal 80GB IDE Drive
 
[owen@LinuxBlog ~]# hdparm -t /dev/sdb
/dev/sdb:
Timing buffered disk reads:   62 MB in  3.09 seconds =  20.06 MB/sec
 
sdc is an internal 160GB IDE drive
 
[owen@LinuxBlog ~]# hdparm -t /dev/sdc
 
/dev/sdc:
Timing buffered disk reads:   90 MB in  3.03 seconds =  29.70 MB/sec

The next two tests are rather interesting. sde is a brand new freshly formated 1TB external Western Digital MyBook Drive.

[owen@LinuxBlog ~]# hdparm -t /dev/sde
 
/dev/sde:
Timing buffered disk reads:    2 MB in  7.69 seconds = 266.25 kB/sec
[owen@LinuxBlog ~]# hdparm -t /dev/sde
 
/dev/sde:
Timing buffered disk reads:   68 MB in  3.01 seconds =  22.60 MB/sec

The first result was what the read time is like when you first initialize the drive. Since the drive was in power down, the read time was horrendous. This was fixed second time around. You will notice that the transfer rate over USB 2.0 is not all that bad in comparison to the internal IDE. Both IDE drives are not primary drives, and are also on the same channel. I’m not sure if that makes a difference or not. Also when I try to set DMA and 32 bit support I get an IOCTL error indicating that something went wrong, so I don’t think that this is a fair test.

Either way, post your results, if see if you can tweak the hard drive settings then see what the read times are. Check out my: Hard Drive Tuning with hdparm article.

Logging Sessions to Twitter

Filed under: Linux Software — TheLinuxBlog.com at 12:01 am on Wednesday, August 20, 2008

If you follow me on Twitter you would know I asked everyone if there was anything that they wanted me to write about. @Ben_Marvin responded and asked about logging the commands you type to Twitter.At first, I thought that this could be done with history, which it probably can be, but does everything you type really have to be echo’ed to Twitter? I don’t think that you’d have many friends, Twitter would probably hate you and you’d most likely hit your maximum requests per hour pretty quickly.The Script command is another option, and this works quite well for this purpose. Read the script man page to find out more about this program. It basically (when ran) takes the I/O from your terminal and logs it to a file. Its a very handy utility.So, how do we get this data into Twitter? First of all, Twitter doesn’t allow very long posts so echoing out the data that the commands you type is not really practical. The best way to do it is to use script to log the session, exit the session and grep for the “]0\;” string for stuff you typed & not the responses.Here is the code:

script; grep ]0\; typescript 

You can then copy and paste it to your favorite Twitter application or pipe it to a scrubbing script to remove the formatting and do the correct HTML stuff, then post it via the http interface. Either way, it can be done even though I don’t think it really should.

Changing Window Manager on Fedora

Filed under: General Linux,Linux Software,Quick Linux Tutorials — TheLinuxBlog.com at 8:34 am on Monday, August 18, 2008

TheLinuxBlog.com was intended to be a blog where I could log my thoughts, findings and generally keep track of how to do stuff. Since it was started this is still the goal. Ultimately I’d like to refer to TheLinuxBlog on how to do something just as much as I refer to google for everything else. That being said, one thing that recently came up for me was “How do I change my desktop on Fedora”.

I had done this before but I couldn’t remember the command to do so. Well, since this blog is as much for me as it is for the reader I figure I can post the how to here and kill two birds out with one blog post, I mean stone.

The program I use to change my window manager on Fedora is: switchdesk.

Switchdesk can be installed by Yum or if you installed Fedora from DVD or CD and didn’t fine tune your packages then you probably have it already. All you have to do to run it is type:

switchdesk

Now, if you are in an X session you will get a nice graphical dialog that will help you change your desktop manager. If your at the terminal it will exit and ask you nicely to type either gnome, kde, xfce or any other window manager you may have installed.

Don’t ask me why every distribution has a different named command and interface to achieve the same thing thats just the way it is. Maybe one day I’ll get a list of all of the commands and post them. Alternatively if anyone wants to start a list feel free to post them in comments or by e-mail.

Whats your take on proprietary software?

Filed under: General Linux,Linux Software — TheLinuxBlog.com at 11:57 am on Monday, August 4, 2008

Using proprietary software to some Linux users is considered a sin, right up there with not reading the manual. Not everyone that runs Linux feels this way. I for one don’t mind using a commercial / propriety product if the product serves the purpose well, and perhaps better than an open source implementation.

Take VMWare server for example. Although it does have its problems, it works very well for virtualization. Its pretty stable, has a good interface, works well and most of all is free. I have no problem installing and using this as long as it works.  I’ve been using it for a while, its what I’m used to and I have no problems with it. The moment VMWare Server stops working, I’ll try to find another alternative. Be it open source or not.

I don’t get why some people are so into the open source movement. Not tainting a system to me has no clear advantages. If I were to not install any proprietary software I would hardly be able to use my Linux box. Think about it, no Java (ok, I’d have the IcedTea runtime and GCJ), but no supported Java for Tomcat / Eclipse, I’d have no Flash, hardly any video codecs and no 3D accelerated graphics. My virtualization, may or may not work depending on what day of the week it was or if I had supported hardware. There is probably a whole lot more that I am missing that I don’t even know about.

So, I’m just interested to know what is every one else’s take on using proprietary software? Am I alone in being “fine” with installing closed source / proprietary software? Is my computer going to go to robot hell and sing with Bender for eternity? Please let me know your thoughts.

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