PawEng » Linux

Windows vs Linux vs Mac OS

PawEng — Tue, 28 Apr 2009 02:13:26 +0000

The gHacks blog has a post about the 5 Things Linux does better than Windows. Reading it got me thinking about a situation I had recently. I had close to 40 thousand text files, and I needed a list of all unique files. I wouldn’t even know how to attach that problem in Windows. With Linux, it only took a few minutes: Using “find” to identify the files, “md5sum” to generate a hash for each file, “sort” to sort them, “uniq” to remove files with identical hash values, and “cut” to remove the remaining hash values. Putting it all together:

$ find . | xargs md5sum | sort | uniq -w 32 | cut -b 35-

Of course, there are other situations where Windows is better. It is, for example, the de facto standard in today’s business world where everyone has a laptop running Windows. Picking a non-Windows laptop for business would be just asking for trouble.

The gHacks post says it well:

[...] the truth of the matter is, there are certain aspects of the Linux operating system that are just plain better than Windows. And, of course, there are certain aspects of the Windows operating system that are better than Linux. And…of course…there are certain aspects of OS X that are better than either Windows or Linux. It’s a three way street here.

VLC Media Player Version 0.9.9 Released

PawEng — Sun, 05 Apr 2009 00:58:17 +0000

VLC Media Player version 0.9.9 has been released. It is mainly a bug-fix release.

VLC is a free and open source cross-platform media play. It supports a large number of multimedia formats, and it can stream sound and video between computers. VLC is one of my favorite media players. I especially like how it can read DVD ISO images directly without the need for mounting them in virtual DVD drivers.

Purge Temporary Files

PawEng — Fri, 23 Jan 2009 00:15:45 +0000

Many Linux / Unix programs create temporary files with names like “#file#” or “file~”. If a program crashes, you may be left with “core” files. These files serve a purpose, but quite often it is useful to remove them. I have been using the script below for a decade or more to keep my directories clean.

#!/bin/sh # # Remove temporary files # # Usage: purge [-r] # if [ "$1" = "-r" ] then find . $ -name '#*#' -o -name '*~' -o -name '.*~' -o -name 'core' \ -o -name '*.spell' $ -print -exec rm -f {} \; else FILES="#*# *~ .*~ core *.spell" /bin/rm -f $FILES fi

Copy the code above to a file named “purge”, and give the file execute permissions:

% chmod a+x purge

Now write “purge” at the prompt to clean the current directory, and “purge -r” to clean recursively down into sub-directories.

Run Linux Under Windows

PawEng — Sun, 04 Jan 2009 15:27:19 +0000

Now that computers have become so powerful, it is possible to simultaneously run multiple operating systems on a single computer. I like to use Windows as my main operation system, but sometimes I need access to a Linux system. Dual-booting Windows an Linux is possible, but often I want to juggle back and forth between the two. Constantly rebooting is too painful.

My solution is to run Linux on a virtual computer. I downloaded Microsoft Virtual PC 2007 and installed it. It is free software, and it allows you to create virtual computers on your Windows machine. There are other virtual computer solutions, but Virtual PC works for me.

The next step is to use Virtual PC to create a virtual Linux computer. I decided to go with Debian Linux. It is a very stable Linux distribution. I don’t care about always getting the latest and greatest, but I do insist on stability. I downloaded the Debian 4.0 distribution CD image. I chose the 180 MB net install image available here.

I followed the step by step instructions by Bil Simser to create my virtual Debian Linux box: Visual Debian Installation Walkthrough using Virtual PC. He describes how to get a console / shell version of Linux up and running. Like him, I am not interested in the graphical desktop of Linux.

Once my virtual Linux box was up and running, installed Samba on it. Samba allows you to access your Linux file system from within Windows. I followed the instructions on Arkinex for Installing and Configuring Samba on Debian 4.

Debian comes with a nice package installation system. To update my Debian computer, I simply type:

$ su - $ apt-get update $ apt-get -u dist-upgrade $ exit

I often need more than just one interactive shell at a time. You can log in to your virtual computer using a terminal program like putty. Or you can use the screen command, which is a full-screen window manager that multiplexes a physical terminal between several processes. Basically, it lets you use multiple interactive shells in a single window. Read this quick tutorial if you don’t know the screen command.

To install screen on your Debian virtual computer, write:

$ su - $ apt-get -u install screen $ exit

Backup Your Gmail Email

PawEng — Fri, 12 Dec 2008 02:29:38 +0000

So you use Gmail as your main email account? But what happens if you get locked out of Gmail? What if you can’t access your email? That is a pretty serious situation in today’s world where more and more things happen online. This is where Gmail Backup comes in. It is a tool for backing up your Gmail email. It is very simple to use. First you need to enable IMAP in your Gmail account. Then you run Gmail Backup. It asks you for your email address and password, and where you want to place the downloaded email, and off it goes to download all your email. It is simple and easy to do, and it gives you peace of mind knowing that you always will have access to your email.

Gmail Backup works for both regular Gmail accounts and for Google App account. It is a free download for Windows and Linux.

Cheat Sheets

PawEng — Tue, 25 Nov 2008 01:38:38 +0000

Scott Klarr has collected a huge number of cheat sheets for everything from programming to Photoshop. They are organized in groups, and some groups like the Linux / Unix group contain more than 70 cheat sheets. The groups include:

C, C++, C#
Gimp
Windows
Networking
Linux / Unix
Designer color charts
Vi & Vim
Emacs
Photoshop
Perl
Regular Expressions
MySQL
PHP
CSS
Javascript / Ajax
Html

The cheat sheets are available at Scott Klarr’s Cheat Sheet page.

Unix, Vim, and Emacs Tricks

PawEng — Sat, 08 Nov 2008 02:45:51 +0000

Slashdot asked their readers to write about useful tricks for Unix, Vim, and Emacs. It makes for some interesting reading.

Update on 11/10/2008: Slashdot posted another one: (Useful) Stupid Regex Tricks?

TrueCrypt Disk Encryption Software

PawEng — Sun, 02 Nov 2008 23:26:06 +0000

TrueCrypt is free open-source disk encryption software for Windows Vista/XP, Mac OS X, and Linux. It provides transparent on-the-fly encryption. You can create and mount encrypted drives — either as separate files or entire partitions. TrueCrypt uses AES-256, Serpent, and Twofish encryption.

TrueCrypt has the ability to create encrypted volumes inside one another. Since a TrueCrypt volume looks just like random data, this gives you plausible deniability: You may be forced to reveal the password to your outer TrueCrypt volume, but there is no way to determine whether you have a hidden TrueCrypt volume within it.

TrueCrypt supports encryption of an entire system drive. For example, you can encrypt the drive where Windows is installed and from which it boots. And the strange thing is that despite the encryption overhead, it may actually speed up your system — see “Security Now! Transcript of Episode #133” for details.

TrueCrypt version 6.1 was just released a few days back.

High Dynamic Range Photos

PawEng — Tue, 21 Oct 2008 00:40:21 +0000

A digital camera’s sensor has a more limited dynamic range than the human eye. This means that if you expose a photo for the bright areas, the camera may not “see” details in the dark area that your eye can see. Likewise, if you expose a photo for the shadows, the camera may not “see” details in the bright areas. This makes it difficult to capture a photo of what you see.

High Dynamic Range (HDR) imaging techniques take a series of normal (or Low Dynamic Range) photos and merge them together to form a single HDR photo. Now it is possible for the photo to show details in both the bright and the dark areas. Depending on the light in the scene, you may want to capture multiple shots; for example, it is not uncommon to merge up to five (or even more) photos.

Qtpfsgui [via gHacks] is an open-source program for generating high dynamic range (HDR) photos. It is free, and available for Windows, Linux, and Mac.

Photomatix is a commercial HDR program for both Windows and Mac. The basic version, however, is free to use.

Photoshop CS3 is certainly not free, but it has HDR support.

HDR imaging is fun to try. Many HDR images tend have unrealistic colors. However, HDR imaging is also able to produce amazing photos.

There are a number of excellent HDR tutorials available online.

OpenOffice.org 3.0 Released

PawEng — Tue, 14 Oct 2008 22:27:23 +0000

Version 3.0 of the free, multi-platform, multi-language office package OpenOffice.org has been released. The release has been long awaited. The OpenOffice.org website is so busy that only a bare minimum download page is available due to overloaded servers. I have been using previous versions of OpenOffice.org for a while, and I look forward to trying out version 3.0