Except for the eye-candy, colors may help when it comes to clarity, although some prefer the default monochrome approach. At the start of this article there is the actual code which can be copied and pasted inside the ~/.bashrc file, and which can be modified depending on each person’s preferences. If you don’t care about what it does you can just insert it in ~/.bashrc, restart your terminal and start reading some man pages to see how it looks (e.g. man man). After this part I tried to explain how this code works and how to modify it in order to get new ‘themes’.

For this tutorial we’ll be editing the ~/.bashrc file, which is a hidden file located in your home directory which gets read each time a new Bash instance starts up. Bash reads all the commands found in this file and executes them (hence the rc part, which stands for run commands).

We will edit this file and add some lines which specify certain colors for the $LESS_TERMCAP variables.

Don’t forget to reset your terminal after entering this code in order for the changes to take effect, e.g. type reset or exit and start up another shell.

This will mostly use magenta and cyan as the colors. Next, I’ll explain what these lines mean and how you can modify the colors.

As you can see, there are several variables which are assigned different values. As shown in the comments after the # sign, every one is used when needed. When text is in bold (double-bright mode), the formatting option is set to bold and the color magenta.

Let’s take, for example, the following line:

This line could be broken into this:

• the environment variable LESS_TERMCAP_md will be assigned the value to the right of the equal sign
• the right side says execute the command between the $( and ) characters, just like the older ` ` did
• printf is a command similar with C’s printf and means “print with format”. The characters between the double quotes specify a color and a font style (e.g. in this case, bold and magenta).

The part that is inside the double quotes are format specifiers like bold, regular, or color to be used. More on these can be found on Wikipedia, here.

The color codes are as follows:

• 30 – black
• 31 – red
• 32 – green
• 33 – orange
• 34 – blue
• 35 – magenta
• 36 – cyan
• 37 – white

Some other escape codes which you could use include:

• 0 – reset/normal
• 1 – bold
• 3 – italic/reversed
• 4 – underlined
• 5 – blink

You can check this by typing in a terminal something like:

So, if we have something like printf ‘\e[01;33m’ it means enter bold and color yellow, according to the listing above.

export is a Bash built-in used to assign values to variables in such a manner that any subsequent application that runs in that shell will be aware of the variable’s value. If, for example, we would simply assign a value to a variable, say MYVAR=”this is my variable” and we would then issue echo $MYVAR, we would see that the variable’s value will be printed. However, try to make a simple script which would echo it, for example:

And then run it e.g. bash myscript.sh – you will see that the value is lost, not visible in the script. So this is where export is useful, because it will make any further script or application “see” the variable. When we invoke the man command, it will need to see the values for our LESS_TERMCAP variables.

Here is another color scheme:

• http://www.ibm.com/developerworks/linux/library/l-bash/index.html
• en.wikipedia.org/wiki/ANSI_escape_code
• http://www.gnu.org/software/termutils/manual/termcap-1.3/html_mono/termcap.html
• https://wiki.archlinux.org/index.php/Man_Page
• http://tips4linux.com/color-man-pages-in-linux/

In this tutorial I will start from the basic ways of using find and head up into showing more complicated (but very useful) ways of getting the most out of it, in order to search and display exactly the results that you are looking for. The version of find that I currently have installed is 4.4.2, as it comes with Ubuntu 12.04 Precise Pangolin, and Bash 4.2.20 (older versions should work without problem too). Special thanks go to http://www.commandlinefu.com/ for some really great one-liners.

If you’re not familiar with the terminal, command-line or Linux in general I suggest you read my introductory tutorial here: Introduction to Linux Command-Line for Beginners.

The simplest way of using find is by typying it in a terminal:

find

This will list all the files and folders (including hidden ones and their sub-files and sub-folders) in the current directory, following the whole hierarchical structure. This will usually generate a long list of files and doesn’t seem to give us much. It’s exactly the same as:

find .

Where . is the currently working directory. This will list all the files and folders in the currently working directory.

It’s probably best to use a new folder somewhere in the file system to see this in effect, a folder which doesn’t have many sub-folders and files.

Moving on, let’s search for all the files that include the name profile in their filename:

find . -name *profile*

* is a wildcard that replaces any number of characters or no character. The above command searches in the current folder for the name *profile*.

find /usr/share -name FreeSans*

This will search inside /usr/share for all the files that start with FreeSans (and end in whatever characters e.g. FreeSans.ttf). I recommend using double quotes around the pattern to search for e.g. find . -name “.bash*”.

Another example:

find /usr/share -name FreeSans* | grep Oblique

So now you know how to search for a certain filename in a specific location.

Sometimes you need to ignore uppercase and lowercase and just search for text by ignoring case-sensitive. We’ll to this just by replacing -name with -iname:

find /usr/share -iname FREESANS*

find . -mtime +3 -iname *somefile*

This will search for files that were created earlier than 3 days ago.

find will return the whole path to the files that match the search pattern, so in order to get only the filename you can use the printf argument:

find /usr/bin -name "alsa*"

To get only the filename, use:

find /usr/bin -name "alsa*" -printf "%f\n"

To search for files by size, use the -size argument, for example:

find /usr -size +500k -name "*png"

This will search inside /usr for files which are equal to or larger than 500 KB and are ending in png. Another example:

find /usr -size +1M -name "*png"

Which will search for files which are bigger than 1 MB in size. Instead of the plus sign, you could use minus in order to search for files that are smaller than a specified size:

find /usr -size -10c -name "*png"

The -10c specifier tells find to only display files which are smaller than 10 bytes. Don’t forget the + or – preceding the desired filesize.

You could use a pipe and the xargs command for this:

find /usr/lib -size +2M -name "*.so" | xargs ls -lh

Notice that this will list the files in the current directory if find returns no file.

This is probably one of the most useful ways to search for some file which name you’ve forgot but you know some of the text it contains inside.

find . -name "*bash*" -exec grep -l "aliases" {} +

This will search in all the files that contain the patter bash for the word aliases. Those files that contain this pattern will be printed out.

Find top 20 largest files:

find . -type f -print0 | xargs -0 du -h | sort -hr | head -20

Special thanks go to http://www.commandlinefu.com/ and the following articles:

• https://www.linux.com/learn/tutorials/316404-10-tips-for-using-gnu-find
• http://www.ibm.com/developerworks/aix/library/au-unix-find.html
• http://www.linux.ie/newusers/beginners-linux-guide/find.php
• http://www.cyberciti.biz/faq/howto-recursively-search-all-files-for-words/

In order to change it, edit this file as root with a text editor, e.g.:

sudo nano /etc/default/grub

Then find the option GRUB_GFXMODE and insert your preferred resolution, e.g.:

GRUB_GFXMODE=1024x768

Now save the file (Ctrl+O followed by Enter if you used Nano for editing), and issue the following command in your terminal:

sudo update-grub

This should be all, the next time you restart your computer the new resolution should be changed.

telnet
telnet is a well-known command-line tool which uses sockets to open a TCP connection to the specified hostname and port. telnet can be primarily used for non-secure connections to connect to a HTTP server and get a file or to an IRC server for example. Escape character in telnet is ^] (press Ctrl+])
Homepage

rtorrent
I’ve never used a BitTorrent client in command-line mode (KTorrent is my application of choice), so rtorrent was something new to me. However I heard about rtorrent many times and decided to take it for a spin. The only reason for choosing it over ctorrent was that everybody mentions it when it comes to command-line tools. Well, after starting it I had trouble quitting it (:q, q, ^X followed by quit or exit didn’t seem to work), so I had to Google for it. The command for exiting rtorrent is ^Q (Ctrl+Q). rtorrent features pausing/resuming torrents, and it features most of the features found in graphical clients like Deluge or KTorrent.
Homepage

vifm
vifm is a twin-panel file manager using ncurses and Vi keyboard shortcuts. I recommend it to those who are used to work in Vi (this is why I recommend CMus for them too, because of the keyboard shortcuts).
Homepage

emacs
Yes, Emacs can be run in command-line mode too, if it is invoked with emacs –no-window-system, or with emacs –no-window, or just with emacs -nw. For those of you don’t know what Emacs is: well, first of all it is a very powerful IDE (Integrated Development Environment) written in Elisp (Emacs Lips, a List dialect). It features syntax highlighting, indentation, so-called “modes” for various languages (including C or Java modes). Emacs is extremely flexible, comes with a huge number of configuration options (which can be used either from within the application or in the ~/.emacs configuration file), and it can be expanded using Lisp. Except for being an IDE, it also provides email client, facilities to use it as a file manager, IRC access, and much, much more. As they describe it on the website, Emacs can be look at just as it would’ve been an operating system.
Homepage

mutt
mutt is a pretty powerful command-line email client. It has support for color terminals, MIME, OpenPGP.
Homepage

iptraf
iptraf is a network interface monitoring tool. It displays various informations on the incoming/outgoing traffic on the installed networking interfaces, statistics and general info.
Homepage

screen
GNU Screen is used to run multiple programs in a terminal, without the need to open several terminal tabs, so it would be a perfect fit to run in the F1-F6 classic ttys. Screen creates several virtual terminals and allows you to customize and switch between them. This tool is definitely a must-have for any respectable power user.
Homepage

tail
tail is a simple tool that will display by default the last 10 lines in a text file. By invoking it with a number parameter, it will display n lines starting at the end of the file (e.g. tail -20 to display the last 20 lines in a file). tail is useful to see the output of long logs.
Homepage

wget
wget is the “de-facto” command-line utility to download files over Internet, supporting the following protocols: HTTP, FTP, HTTPS and HTTP through proxies. It provides for many options, including quiet mode, verbose or non-verbose mode, resume downloading an incomplete file, set the number of retries, and these are not the only ones.
Homepage

hnb
hnb stands for Hierarchical Notebook, it is written using ncurses, and it allows you to keep notes in a console.
Homepage

In the next article in these series I will talk about ssh, scp and several other powerful and useful tools.

Here are some of the main features provided by PeaZip, according to the official website:

• easy to use GUI, powerful integration with scripts
• portable version for running it from removable devices
• it can work with all the popular archive formats
• tools to extract, compress, convert, encrypt, secure delete and save backup scripts
• fast, with a high compression ratio, stable and secure
• comes with packages for various distributions, also generic Linux packages
• it has both GTK and Qt interfaces (GTK interface is the recommended one)

To install it in Ubuntu 11.04, download the DEB package from
here then open a terminal, make sure the current working directory is the one where you saved the .deb file, and type in the following command:

sudo dpkg -i peazip_3.8.LINUX.GTK2-2_all.deb 

To run it type in the terminal peazip or press Alt+F2 and type peazip in the run box. Here’s how it looks like:

And the configuration window:

Gnac is a GUI frontend to various audio converters, with a very minimalist and clear interface. It allows to edit the tags, change the path and filenames of the output files, and use custom parameters for audio encoding. For example, the Ogg Vorbis format profile
can be configured to use variable or constant encoding bitrate, change the quality settings on a scale of -0.1 to 1.0 (~ 45 kbps up to ~ 500 kbps), use mono or stereo audio channels, or set a minimum and maximum bitrate.

The Ogg profile settings

The MP3 profile settings

The Preferences window will let you enable or disable a conversion notification icon, set custom output folder, strip special characters, or delete original files after the conversion. Here you can also customize the folder hierarchy and the information to be included in the output filenames (e.g. %n_%a _%b_%t for Number_Artist_Album_Title).

Ubuntu Installation

To install it in Ubuntu from the official Launchpad PPA, run the following commands in a terminal:

sudo add-apt-repository ppa:gnac-team/ppa
sudo apt-get update
sudo apt-get install gnac

To start it type gnac in a terminal or press Alt+F2 and type gnac in the run box that appears.

Starting a server should be pretty straightforward in Linux, all you have to do is run the server dedicated binary with several parameters, however AssaultCube provided a script, called server.sh for doing it. Here’s an example:

./server.sh -c20 -xserverpass -Bconfig/serverblacklist.cfg -n"Public AC Server" -o"Welcome to our AssaultCube server!"

This is a perfectly working example, and you will be able to see your server listed in the Server Browser under the name “Public AC Server”. Here is what the switches used mean:

-c20 – the maximum number of clients allowed (20)

-xserverpass – the admin password (-x is the switch and serverpass is the actual password)

-Bconfig/serverblacklist.cfg – the -B switch specifies the blacklist file (banned IPs), in this case config/serverblacklist.cfg

-n”Publci AC Server” – the name of the server, which will appear in the Server Browser, you can use the slash (\) to escape characters like $

-o”Welcome to our AssaultCube server! – this is the welcome message which will be displayed to each player after he joins the server

For a complete list of parameters, see this page on the official website.

Installation from the Firefox Next PPA

Open a terminal and type in the following commands:

sudo add-apt-repository ppa:mozillateam/firefox-next
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install firefox

Notice that these commands will install the latest Firefox version available in the PPA, which means it will replace your existing Firefox version.

The first command will add the PPA repositories inside your /etc/apt/sources.list.d/ directory, in a file called sources.list.d/mozillateam-firefox-next-natty.list. Alternately, you can edit the /etc/apt/sources.list file by hand and add these repositories manually:

deb http://ppa.launchpad.net/mozillateam/firefox-next/ubuntu natty main
deb-src http://ppa.launchpad.net/mozillateam/firefox-next/ubuntu natty main

Removing latest Firefox and downgrading to the version in the repositories

If you want back Firefox 4, you can type in a terminal:

sudo apt-get install ppa-purge
sudo ppa-purge ppa:mozillateam/firefox-next

The first command will install ppa-purge, which is a package used to disable the specified PPA from your sources and revert to the version of the package in the default repositories.

Manual installation

Another way of installing Firefox is to just download it from their website, here – direct link for Firefox 5 b5 US English. Next uncompress it to a location of your choice (for example I use here /home/USER/apps/) and then run the firefox script from within the firefox directory. However, you can run Firefox 4 and Firefox 5 in parallel by using profiles and the -no-remote switch. To do this, open a terminal and run the firefox script like this:

/home/USER/apps/firefox/firefox -P -no-remote

The -P switch tells Firefox to open up the profile window at startup, so you can create or choose a profile (a new profile will open Firefox with all the settings default, without bookmarks, add-ons, themes, or personas installed). The -no-remote switch tells Firefox not to connect with any other running Firefox instances, so you can actually run Firefox 4 and Firefox 5 at the same time without trouble. Here are a few screenshots of the profile window:

First, start firefox with the -P and -no-remote switches. In the profile window that pops up, click Create Profile:

Now select you’re newly created profile and click on the Start Firefox button:

Firefox 5 Beta

From the add-on page description, Flash-Aid is a Firefox 4 and 3.5 (and maybe 5 Beta too) add-on which was built to “Remove conflicting flash plugins from Ubuntu/Debian Linux systems, install the appropriate version according to system architecture and apply some tweaks to improve performance and fix common issues.”

Well, I must say it sounds promising at least, especially since the page says it’s designed especially for Ubuntu. Let’s see how it works with Firefox 4.

I wanted to remove my manually installed plugin from ~/.mozilla/plugins, but since the description said Flash-Aid will do it, I’ve left it in place. Then I installed it from Mozilla’s add-ons page (https://addons.mozilla.org/en-US/firefox/addon/flash-aid/), restarted Firefox, after which Flash-Aid created a non-intrusive icon in the right side of the navigation bar. No option to disable it or have a menu entry instead of a toolbar shortcut though.

Flash-Aid offers two ways of installing Flash, either by using the Quick Mode (which allows you to choose between the “stable” Flash included in the Ubuntu repositories and the “Beta” version from Adobe website), or by using an advanced mode, which also offers Gnash as an alternative, or allows you to supply a custom HTTP or FTP address.

Flash-Aid correctly detected and removed my currently plugin from inside ~/.mozilla/plugins, and after asking for the root password it fetched and installed the 32-bit plugin from Adobe homepage. The steps were pretty straightforward I believe:

Removing already installed Flash plugins

After prompting for the admin password, it starts installing the selected version of Flash

Considering the steps – install the add-on, restart Firefox, let Flash-Aid install Flash as root, then restart Firefox again, it’s pretty fast. It has the advantage that it detects the right version you need (32-bit or 64-bit), it removes old or incompatible Flash plugins that are eventually installed, and most important, it will install at demand the latest Flash version, since repositories ship the same version for a whole release cycle.

Download and install Flash-Aid
Homepage
http://ubuntuforums.org/showthread.php?t=1778817

Aliases are handy custom commands which can be used to make shortcuts to various commands, scripts or one-liners. Aliases can be added in the ~/.bashrc file like this:

alias name='command'

Alternately, you can specify an external file and load it in .bashrc, like for example the default one, called .bash_aliases. Edit .bashrc and uncomment or add (if it doesn’t already exist) the following code:

if [ -f ~/.bash_aliases ]; then
    . ~/.bash_aliases
fi

This code checks to see if the file ~/.bash_aliases exists, and if it does, it reads the contents from it. Here are examples of aliases and what they do:

alias killfx='kill -9 $(pidof firefox-bin) # kills Firefox by sending SIGKILL using its process ID
alias upgrade='sudo apt-get update && sudo apt-get upgrade' # upgrade a Ubuntu-based system
alias xterm='xterm -geometry 1280x1024' # start xterm with a custom geometry
alias src='. ~/.bash_profile' # source the ~/.bash_profile (read its contents and execute them)
alias lsh='ls -lhXG' # alias for ls to use long listing format, human readable sizes, sort and don't show groups

You can virtually define any aliases you want here. The # sign used after each alias means what follows is comment, it will be ignored by Bash when reading the file.

Here’s another tip. Adding the following two lines to ~/.inputrc will make PageUp and PageDown keys to search through history (if ~/.inputrc doesn’t already exist create it):

"\e[5~": history-search-backward
"\e[6~": history-search-forward

Now if you type a command followed by PageUp it will search for the last command that started with the pattern you specified.

Special thanks go to Alex Dekker for this tip.

For this we will precede the files (or arguments) that start with “-” with “–”. For example:

man gcc | grep -- -ansi

Will show only the lines which contain the pattern -ansi in the gcc manual page. Or:

touch -- -file
rm -- -file

Will create a file called -file and then it will remove it. Also, ls -l — -file will use long listing format to show details about -file.

Special thanks go to Lawrence D’Oliveiro for this tip.

The big advantage of these is that they use Ctrl and Alt (Meta) combination, which for a person who knows blind-typing is very useful, since he will not need to move his hand to reach keys like arrows, PgUp, PgDown, Home or End. Most of these shortcuts are used in the shell for fetching commands from history, edit text in a fast manner, or even navigate quickly in less pagers or in a manual page. Here are the shortcuts (^A means “press Ctrl and A at the same time”):

• ^A – go to the start of line
• ^E – go to the end of line
• ^H – erase one character to the left
• ^D – erase one character to the right, it also exits the shell by default if there is no character to delete
• ^U – erase everything from the cursor to start
• ^K – erase everything from the cursor to end
• ^P – bring the previous command in history
• ^N – bring the next command in history
• ^C – interrupt character, sends SIGTERM to the current application

Colored manual pages can really make text clearer and easier to read. Here’s a snippet I took from the web a while ago (I really don’t remember the address where I found this particular customization scheme – could it be from here?). Put the following inside ~/.bashrc:

export LESS_TERMCAP_mb=$'\E[01;31m' # begin blinking
export LESS_TERMCAP_md=$'\E[01;38;5;74m' # begin bold
export LESS_TERMCAP_me=$'\E[0m' # end mode
export LESS_TERMCAP_se=$'\E[0m' # end standout-mode
export LESS_TERMCAP_so=$'\E[38;5;246m' # begin standout-mode - info box
export LESS_TERMCAP_ue=$'\E[0m' # end underline
export LESS_TERMCAP_us=$'\E[04;38;5;146m' # begin underline

And then source your .bashrc file:

. ~/.bashrc

Here’s how the manual pages will look now:

This is yet another tip for working faster using either Shift+Insert or the middle mouse button. They both do the same thing: enter text from the clipboard in either the command-line or a shell text editor, like Nano (also works in Emacs, together with ^Y).

With only basic Bash knowledge you can create your own time-savers scripts, or just fun ones. I have my own scripts inside the ~/bin directory, which is included in my $PATH. For example, here is a greeting script:

echo "Welcome to the dark side of the moon, $USER!"
echo 'System uptime:'
uptime
cal

Save it with a suggestive name, say greeting.sh and put it inside ~/bin. Now edit your ~/.bashrc file and add the following line:

. ~/bin/greeting.sh # or "source ~/bin/greeting.sh"

Now open a new shell to see the new greeting, or just source your ~/.bashrc file:

. ~/.bashrc

Here’s how this looks like on my system:

This tip can be used with virtually any command, since Bash will expand it, but it’s very useful for creating backup files. Say you have a filename called very_long_filename. To rename it you would normally do something like mv very_long_filename very_long_filename.backup. But here’s how to do it faster:

mv very_long_filename{,.backup}

Bash will expand this command into the one showed above, and then execute it.

Do you have some more additions to this? Please feel free to use the comments below and share them with us!