Linux Blog

Add or Remove Repositories

HLA91 — Sat, 19 Jun 2010 15:30:10 +0000

Too add or remove repositories, simply edit
sudo pico /etc/apt/sources.list
To make a backup before hand
sudo cp /etc/apt/sources.list /etc/apt/sources.list.backup

Using ZIP file in Linux

HLA91 — Thu, 19 Nov 2009 18:19:57 +0000

To zip files for use on Windows & Linux then use the zip program. I think it comes as standard on some distributions, to find out if you have it installed open a terminal and type zip if you get
command not found
then install it with
sudo apt-get install zip
if a load of text scrolls past then your fine, it is already on your system.

To zip a file use
zip zip-file-name file-to-be-zipped
make sure you include the file extension of the file to be zipped.

To include sub-directories and hidden files
zip zip-file-name .* .
Note: there is a space between the asterix * and the last stop

To include all sub-directories in the current direcotry then use
zip -r zip-file-name .

Finally I have shown you how to zip files so now I will show you how to unzip them
unzip zipped-file

Again, for more info please consult the man pages man zip

Using RAR file in Linux

HLA91 — Thu, 19 Nov 2009 18:07:10 +0000

If you receive a .rar file and don’t know what to do with it then simply install unrar
sudo apt-get install unrar
Then unrar it with this command
unrar e file.rar
For more info use the man pages
man unrar

Processes: List current Processes

HLA91 — Mon, 14 Sep 2009 18:07:58 +0000

If an application crashes on you, or you simply want to see what’s running then simply issue the ps command.
Here are a few arguments you can use with ps, but these are not all of them by all means. try man ps to find out what available

u -provide detailed info e.g. CPU percentage and Memory Percentage
a -list processes of all users on the system, normally a long list
x -list all processes including daemons

An example of ps with arguments is
ps aux
but this list is normally quite long so break it down with the | more option, so the command now looks like
ps aux | more

Deb: Installing .deb files

HLA91 — Mon, 14 Sep 2009 17:35:54 +0000

Ever downloaded a file.deb and wondered what to do with it?Normally double clicking the file will start the GDebi Package Installer, which knows what to do with the file but if that doesnt work on your system then simply install it with dpkg

dpkg --install file.deb

But then again you could always use synaptic?

Packages: Searching for Specific Packages

HLA91 — Mon, 14 Sep 2009 17:30:27 +0000

Want to install a program but don’t know what package its in?

Use
sudo apt-cache search packagename

Simply replace packagename with the name of the program and hopefully the packages matching that description will be listed, but there’s always synaptic?

Download youtube Videos

HLA91 — Mon, 10 Aug 2009 22:01:39 +0000

See a video on youtube that you like, wish you could watch it on your computer without having to navigate to youtube well this is just for you.

Start off by installing the program youtube-dl

sudo apt-get install youtube-dl

Once installed run it by entering the command

youtube-dl -o myvideo.flv "link-to-youtube-video"

Replace myvideo.flv with what you want the local file to be called by obviously keep the .flv extension, that will start downloading the video, normally takes around a miunte or two.

Once downloaded you can normally play the video straight away by double clicking it. I did know some software to convert the video to the more universal .avi format but it doest seem to be working for me at the moment so I will post back when it is working or I have found a replacement.

Terminal: Change Shell Prompt

HLA91 — Sun, 15 Mar 2009 18:52:55 +0000

There are many ways to change the terminal/shell prompt from the standard ones. I have tried many but this one seemed to work for me.
You have to edit the file .bashrc which is located in your home folder. I cannot remember if I had to use sudo for that so try it.

At the end of the .bashrc file insert the following code

export PS1="\u> "

Now logout and then log back in again and your prompt should be
username>
The \u indicated that you wanted the username displayed, for a full list of commands please visit here

IBM Prompt Sequences

Terminal: View Failed root access attempts

HLA91 — Fri, 13 Mar 2009 16:40:01 +0000

To view a list of all the failed sudo access attempts make

/var/log/

your working directory then issue the command

grep NOT auth.log

You can also add some grep arguments. For a brief rundown on grep grep rundown or use the man grep command

Grep: Search a file for a specific word

HLA91 — Thu, 12 Mar 2009 22:07:32 +0000

If you want to search a file for a line that includes a specific word then simply issue the command

grep science science-paper

That would search the file science-paper for the word science and show the line where the word is located

If you want to ignore case sensitivity, in that if you issue the command

grep ScIeNce science-paper

then the word science would still be returned, then simply include the argument

-i

So the command would be

grep -i ScIeNce science-paper

Other grep arguments include

-v display lines that don’t match
-n precede each matching line with the line number
-c print only the number of matched lines

To issue the grep command with multiple arguments just bunch all the arguments together like this

grep -in science science-paper

that would display each line precede with the line number as we include the -n argument as well