Code Retard » Linux

StarCraft Running on PS3

adm_snackbar — Fri, 27 Feb 2009 16:40:41 +0000

Think this is impressive? Want to play StarCraft on your PS3 as well? It’s definitely possible. The requirements? You need to take advantage of your PS3’s little known capability to run Linux. Linux you ask? Yes, because that’s the only way to run Windows. Since StarCraft came out way back in the day when Windows 95 was king, that’s all you need to install on top of Linux through an emulation layer. Fortunately, the PS3 has enough horsepower to run Windows 95, even via software emulation, so StarCraft is actually playable. Just imagine it, playing StarCraft on your big screen TV!

The steps to running Windows on your PS3 are a little bit involved, but we have step by step guides for you. Follow our guide on how to install Linux on your PS3. Then follow our guide on how to install Windows XP on your PS3 or Vista, except replace XP/Vista with Windows 95. Unlike Vista, Windows 95 is actually usable so StarCraft is playable.

After you’ve got Windows 95 running on an emulation on top of Linux, you can then install StarCraft on it.

Download 101 Linux Hacks eBook PDF Free

adm_snackbar — Wed, 18 Feb 2009 18:56:37 +0000

Not sure how long this will last, but if you use Linux regularly, you may be interested in Ramesh’ Natarajan’s eBook Linux 101 Hacks which is currently available for free download from his website at www.thegeekstuff.com. The password to get in is “linuxrocks” and the eBook itself is in PDF format. Subtitled “Practical Examples to Build a Strong Foundation in Linux,” the book is filled with detailed explanations on a variety of useful Linux commands and command options that you may or may not have heard of and “hacks” to make ones you use regularly more effective like a true Linux veteran.

The book is split into nine chapters:

Powerful CD Command Hacks
Data Manipulation
SSH Client Commands
Essential Linux Commands
PS1, PS2, PS3, PS4 and PROMPT_COMMAND
Colorful and Functional Shell Prompt Using PS1
Archive and Compression
Command Line History
System Administration Tasks

The read is highly recommended for experienced and no so experienced Linux users both. Beginners will be able to learn Linux better through these examples and veterans will be pleased to extend their Linux experience with these useful hacks.

Grab the eBook now. What have you got to lose, it’s free and it only takes a little bit of your time.

Compare Directories and File Content in Linux without Dircmp

adm_snackbar — Tue, 17 Feb 2009 20:28:35 +0000

Dircmp is a great Linux tool that allows users to compare the directory contents of two similar directories in order to spot differences in between subdirectory structures or file content. However, dircmp is not a luxury afforded by all Linux distributions. CentOS, for example, does not include the dircmp tool and the source code is not easily available. Plus even if it was, who would want to spend time to build it when you can do the exact same thing with your trusty friend: diff.

Yes you heard right, diff isn’t just for files anymore. In fact, it’s quite useful to compare directory contents if you use it correctly. The important diff options to be aware of are:

–brief: This will not print out the actual differences between files as this level of detail is not necessary in a directory compare. Instead, brief merely points out the fact that there is a difference.
-r: This will recursively execute the diff so that you get a thorough comparison between the two directories

The full usage for dircmp with diff is:

% diff –brief –r dir1 dir2

As an example, let’s take two directories literally named dir1 and dir2. These are their file structures, starting with dir1:

dir1: total 20 drwxrwxr-x 2 user user 4096 Feb 17 11:53 dir3 drwxrwxr-x 2 user user 4096 Feb 17 11:49 dir4 -rw-rw-r-- 1 user user 16 Feb 17 11:49 fileA.txt -rw-rw-r-- 1 user user 460 Feb 17 11:50 fileB.txt -rw-rw-r-- 1 user user 338 Feb 17 11:51 fileC.txt


dir1/dir3:     
total 4     
-rw-rw-r-- 1 user user 0 Feb 17 11:52 fileD.dat     
-rw-rw-r-- 1 user user 2 Feb 17 11:53 fileE.dat

dir1/dir4: total 0

Here is dir2:

dir1: total 20 drwxrwxr-x 2 user user 4096 Feb 17 11:53 dir3 -rw-rw-r-- 1 user user 96 Feb 17 11:49 fileA.txt -rw-rw-r-- 1 user user 460 Feb 17 11:50 fileB.txt -rw-rw-r-- 1 user user 338 Feb 17 11:51 fileC.txt

dir1/dir3: total 4 -rw-rw-r-- 1 user user 0 Feb 17 11:52 fileD.dat -rw-rw-r-- 1 user user 0 Feb 17 11:53 fileE.dat

To sum up, dir1 contains dir4 which is not in dir2. Also the files fileA.txt and fileE.dat are different. Here is the result of the “dircmp” using the diff command:

Files dir1/dir3/fileE.dat and dir2/dir3/fileE.dat differ Only in dir1: dir4 Files dir1/fileA.txt and dir2/fileA.txt differ

And there we have the results exactly as we have expect. The file fileE.at is different, dir4 only exists in dir1, and fileA.txt is different. The results of this output is more than sufficient to give a clear picture of the differences between two directories without resorting to dircmp.

Image/Flickr/K@#$0%

Download Ubuntu Pocket Reference Guide PDF Free

adm_snackbar — Wed, 28 Jan 2009 16:53:05 +0000

For users who using Ubuntu Linux or are considering switching to this popular distro, this free pocket reference guide is available for download in PDF from the book’s website. While the print edition is available for $9.94 from Amazon, The Ubuntu Pocket Guide and Reference PDF is practically identical to the print edition except that it’s absolutely free. The book covers Ubuntu 8.04 LTS, 8.10 and beyond and doesn’t require the reader to have any Linux background. In fact, it’s particularly useful for Microsoft Windows users who are switching to Ubuntu. Linux gurus will still find it useful since it will save them from having to wade through tiresome documentation just to look up a few commands.

Ubuntu Pocket Guide and Reference is a compact yet succinct and comprehensive guide for everyday Ubuntu use. It’s ideal for anybody who needs vital information on working with Ubuntu but who doesn’t have time to wade through thick documentation. First, you’ll learn about installation–getting Ubuntu onto your computer–after which you’ll learn how to configure your computer’s hardware. Following this, you’ll be introduced to the Ubuntu desktop, and the tricks and techniques of efficient day-to-day usage. The book then describes the highways of the Ubuntu filesystem, and gives a full run-down of the Ubuntu file manager. Next, the command-line is tackled, after which software management is explained. Finally, system security is described. Appendixes provide a glossary of terms, and a guide to reading technical documentation. Written for anybody switching to Ubuntu, particularly Windows users, Ubuntu Pocket Guide and Reference assumes zero Linux knowledge.

Visit the download page to grab the Ubuntu reference guide PDF or simply use these two direct download links:

Image/ubuntupocketguide.com

How to Remotely Reboot Linux Machines

adm_snackbar — Tue, 20 Jan 2009 22:17:52 +0000

If you don’t have direct physical access to your Linux box but have the root password, you can easily remotely reboot Linux by executing this simple reboot command. Note that while you can ssh onto the remote Linux host just by itself, you can also send remote commands via ssh as well and this is what we’ll use to execute the restart. This is great if you don’t have direct physical access to your host (or are too lazy to get up out of your seat) but have administrative root privileges to execute a remote shutdown. The command is simple but requires ssh (secure shell) service which should be installed and running standard on just about any Linux distribution. You’ll need to know your Linux machine’s IP address or machine name just as if you were to remotely login to that machine, but instead you’ll execute a remote reboot command.

From any Linux terminal shell, execute:

% ssh root@remote-linux-host rebootor % ssh root@10.11.12.13 reboot

Then the host will reboot automatically, and if there are users still logged in they will be warned as the machine shuts down and powers back up gracefully.

Image/Flickr/Biappi

How to Get Exit Status Codes from Linux Command Prompt

adm_snackbar — Wed, 24 Dec 2008 15:15:00 +0000

Whenever you execute a command in Linux, the command actually returns an exit status code which is useful when you need information on how the execution went like if it failed or succeeded. An exit status code of:

0 means the command executed properly without any errors
1 means the command executed but there may have been some minor issues (think of these as warnings)
2 means the command executed and there was a major problem (think of these as errors)

Getting the exit codes is easy, simply execute any command in Linux. Immediately after, to check its exit status, type

echo $?

and you will see a number printed, which will be 0, 1, or 2. For example, check out this procession:

% whoami coderetard % echo $? 0

This means the command ‘whoami’ ran with an exit code of 0, meaning its exit status was OK. Now check this out:

% cd dir_that_does_not_exist dir_that_does_not_exist: No such file or directory. % echo $? 1

It looks like that didn’t go too smoothly!

To take it even further, make sure your own programs are returning accurate status codes to reflect the exit status. In C, you would do something like this:

#include void func_ok() { // exit code = 0 exit(EXIT_SUCCESS); } void func_fail() { // exit code = 1 exit(EXIT_FAILURE); } int main() { func_ok(); //func_fail(); }

And basically you would exit with EXIT_SUCCESS if everything ran OK, otherwise you would exit with EXIT_FAILURE. This method is preferred over giving an integer value directly into the exit() function as using stdlib macros are more portable across platforms.

Image/Flickr/Biappi

How to Add a Buffer Tab Explorer to Vim and GVim

adm_snackbar — Thu, 18 Dec 2008 18:53:04 +0000

I like to type and have found Vim to be the best editor suited to my style. Although traditionally a Linux text editing tool, it’s been ported to Windows and is a great alternative to match the likes of TextPad, Notepad++, or my fave, Crimson Editor. However, it is missing one basic but major feature that all the other editors have: no tabs! Tabs make it easy to navigate multiple files open at the same time in the same window. While you can split the screen vertically and horizontally, it still doesn’t make up for the lack of a buffer explorer tab (buffers = files in Vim).

Fortunately, adding a buffer tab to Vim is simple, thanks to a freely available extension called Mini Buffer Explorer. It’s actually just itself another buffer window, but the script automates the auto detection of currently open files and new files you open and keeps itself minimally sized as a bar on the top of Vim so as not to take up precious screen space.

The latest version as of this writing, 6.3.2, was last modified a month ago, so rest assured that this script is being constantly maintained. Installation is a breeze: just add the file “minibufexpl.vim” to your Vim plugins directory (~/.vim/plugin/).

When you open a single file, the buffer tab smartly does not kick in as it would be unnecessary. When a second file opens, you’ll see the buffer tab appear up top listing all files currently open. The tab itself takes up buffer 3 so remember this when you open a third file (because it’s actually in buffer 4).

Location of Where Pidgin Chat Logs are Stored

adm_snackbar — Wed, 12 Nov 2008 16:34:07 +0000

Pidgin is my preferred all-in-one chat application. One of its features is the ability to log your chat sessions to text or HTML format. The problem with that is the Pidgin chat logs are saved to some undisclosed location on your computer which varies depending on your operating system platform and unfortunately cannot be set through any Pidgin setting.

Formerly known as gaim, Pidgin is a completely freeware chat program and simultaneously connects you to all the major chat networks like AIM, MSN, Yahoo, ICQ, and Google Talk to name a few. I like it because of its easy usability and no-nonsense interface, very much unlike Trillian which I loathe (disclaimer: I have not looked at Trillian since I last used it seven years ago, it may have changed since, but it sucked in 2001). It’s cross platform so it runs on everything, but requires GTK which is a slight hassle for Windows users who have to install it as well. Fortunately for Mac and Linux users it is usually installed.

The location path where chats are logged are (assuming a username of "coderetard"):

Windows XP: C:\Documents and Settings\coderetard\Application Data\.purple\logs
Windows Vista: C:\Users\coderetard\AppData\Roaming\.purple\logs
Linux: /home/coderetard/.purple/logs or ~/.purple/logs

Image/pidgin

sed: How to Escape Forward Slash with the Right Delimiter

adm_snackbar — Tue, 11 Nov 2008 17:02:53 +0000

If you’ve used Linux at all, you may have come across ’sed,’ short for "stream editor," which is a powerful little utility to modify streams like console IO, files or text. I was using it recently to do a simple search and replace operation in a few files. However, a curious problem arose that I had not encountered before. I’ve used ’sed’ many a time to perform a find and replace on text within a file, but I’d never included the slash ‘/’ (also known as "forward slash") character in my search text with sed. As you may know, sed can easily perform a search and replace on all *.txt files in a directory with this command:

% sed s/text_to_replace/replacement_text/g *.txt

Note how forward slash "/" is used as part of the regular expression to separate the command options and search text. Naturally, since I had text that I wanted to replace with forward slash characters, my sed command contained escaped slash characters and looked like this:

% sed s/file:\/\//http:\/\//g *.txt

I wanted to replace "file://" with "http://" text so in order not to confuse the delimiter with the text, I escaped the forward slashes with backslashes like so \/. Unfortunately, sed didn’t like what I gave it and gave and output like:

sed: -e expression #1, char 10: unknown option to `s'

No matter how I escaped the forward slash or how many other characters I escaped with backslash, sed simply would not do what I wanted it to do. Then I discovered quite an exciting little tidbit about sed. In the regular expression, it’s not necessary to delimit the find and replace texts and search options with the slash ‘/’ character. In fact, you can use just about any character to delimit the expression:

% sed s#file:\/\/#http:\/\/#g *.txt % sed s@file:\/\/@http:\/\/@g *.txt % sed sAfile:\/\/Ahttp:\/\/Ag *.txtUsing #, @, and A as the delimiter will all work out to the same valid sed operation to find all strings of "file://" text and replace it with "http://" text.

Image/Flickr/Biappi

Problems with CVS: “[tag aborted]: cannot rename file, file exists” Error

adm_snackbar — Thu, 09 Oct 2008 14:27:58 +0000

I was happily tagging away my just-released source code on my Cygwin Linux for Windows emulation layer using the good old fashioned Cygwin command prompt with the good old fashioned ‘cvs’ command when my tag aborted suddenly and spit out this error:

cvs [tag aborted]: cannot rename file /my/cvs/repo/,userguide.pdf, to /my/cvs/repo/userguide.pdf,v: File exists

…Much to my horror since it was in the middle of a CVS tag operation. This occurs because of a permissions problem, namely that the file cannot be renamed because you don’t have write permissions for it. This is a peculiar anomaly on Windows only, since I certainly did not have userguide.pdf open anywhere. It turns out that WinCVS, like Cygwin, has this problem as well. It seems to occur because the file doesn’t get closed properly for some reason on Windows. If you’re using WinCVS, try shutting it down and restarting it again. Hopefully it will properly close the file. On Cygwin, there’s not really any way to “restart” anything except your entire OS. To get around this, I simply executed the CVS tag again from a proper Linux terminal. On Linux you won’t get this sort of problem. The tagging operation then resumed seamlessly without any problems, even though it had quit halfway on Windows. Or if you must use Cygwin, restart the OS as I mentioned earlier.