Friday, August 22, 2014

Drum beats with Hydrogen

Hydrogen is an easy to use but advanced drum machine for GNU Linux. You can get into making some drum beats very quickly. It installs from terminal by issuing the following command:

apt-get install hydrogen
You'll love it.

Dr Drumbeat maker for Windows and Mac.

GIMP GNU Image Manpulation Program

I love GIMP. It's my favorite program for quickly editing photos and creating graphics. I've editing icons for graphical user interfaces with GIMP and it is more than sufficient to handle most graphic design projects. To install GIMP just open terminal and issue the following comand.
apt-get install gimp
It installs very quickly. You'll find the interface is pretty intuitive to use like most graphics editing programs. The is usually a complete manual that comes out for each new version of GIMP. So learning the software is pretty easy.


But in all fairness if you want to buy a Photoshop course. I'll make that link available as well.

Tuesday, August 19, 2014

sorting strings with BASH

Sorting strings with BASH. Example email addresses: Say I want to invite my some of my old class mates to an event. But I don't have a mailing list. I do ,however, have a huge list of text files from my classes which contain the all the authors' email addresses. This is what I will to extract the email addresses.

First we'll use grep to grab all of the strings that look like email addresses by issuing a command like this:

grep -hrio "\b[a-z0-9.-]\+@[a-z0-9.-]\+\.[a-z]\{2,4\}\+\b" * > file.txt

Then we'll want to sort them into some kind of order but more importantly we'll remove all of the non-unique email addresses from the list.

sort -i file.txt | uniq -u > newfile.txt

Then we will remove the .mil and .gov domain extensions for obvious reasons.

sed -i '/.gov/d' newfile.txt
sed -i '/.mil/d' newfile.txt

Get a line count to see how many email we have.

sed -n '$=' newfile.txt

Sunday, August 3, 2014

Size of computers

This is what computers used to look like. Any decent smart phone will do more than this computer that took up entire buildings did back in the day.

Here's a link to one of my favorite microcomputers. ODROID-XU3 Is the world's smallest and lowest cost octa-core computer. It's absolutely amazing how far our technology has come in such a short time.

Brief History of Computer Systems Software and Programming

Friday, August 1, 2014

Accessing android devices with gMtP






If you have been using an older Android device like I have and recently upgraded, you've probably noticed the new device is not plug and play for usb storage. New android devices use MTP and you will want to get a program called gMTP to access your android device. Also if you want to enable USB debugging on your Android device you'll want go into settings and tap the about phone option seven times. This will enable USB debugging.

Sunday, July 27, 2014

Fixing issues with Kali Linux repositories

You need to add the correctly repositories to /etc/apt/sources.list then add correct gpg keys. It's pretty quick and easy. I'm surprised I never blogged this yet. So what you want to do is go to this page and get the repository information.

http://docs.kali.org/general-use/kali-linux-sources-list-repositories

In a console add this:


gpg --recv-keys AED4B06F473041FA
gpg -a --export AED4B06F473041FA| sudo apt-key add -

or maybe this


gpg --keyserver pgpkeys.mit.edu --recv-key AED4B06F473041FA
gpg -a --export AED4B06F473041FA| sudo apt-key add -

apt-get update
apt-get upgrade
or apt-get dist-upgrade
This should resolve the problem with the repositories. Sometimes there is a problem with apt configuration when you install the system without a network connection. This happens  with pretty much any Debian based linux. If you install the system with ethernet cable plugged in and use the software mirrors option to install all of the software everything will usually install correctly. I used to have this problem with Ubuntu all the time.

Installing Linux Software Notes

Here's my thing with Linux software installation. First I try apt-get to install it. Syntax is apt-get install <package name>
If that doesn't work I use apt-cache search <package name>
or I'll try software center open terminal and type software-center graphical installer will open if it is installed if not apt-get install software-center. If the programs are not available through software-center use synaptic. Open a terminal and type synaptic. If it is not installed type apt-get install synaptic. Then run it. Search for your package and install it. Most of the time it will automatically install dependencies. If this fails there's always downloading the tarball and tar xvf <package> cd into the package directory then into the source directory chmod 755 ./configure to make the configuration file work. Then run ./configure then make then make install. Qt installers are a little different or running qmake or cmake. The stuff can get confusing. quickly. Make sure to read the install instructions which you probably won't understand from the get go. Google search for the install instructions with valid command line syntax examples. At last resort using something like alien to convert rpm to deb or something stupid like that. Generally if you it is a .deb package it will install with dpkg -i <package> But if it need dependencies you'll have to track those down.

If people are talking about having installed the program and used it. Ask them to post their command line history that is about the easiest way to get install instructions. Open terminal issue history should show the last 500 things you did in terminal.

If a program doesn't install after a few hours of trying just about everything. Email the developer. Most people are pretty approachable and they want their software to be easy to use. It beats posting your question on a linux forum where you are likely to get flamed and not have your question answered at all.