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/

However, there is still possible to change the background image, by using the gsettings tool instead. You will need the libglib2.0-bin package, which is probably already installed on your system. To change the background, use a command like the following:

gsettings set org.gnome.desktop.background picture-uri file:///$PATH_TO_FILE

Where you replace $PATH_TO_FILE with the full path to the file, e.g.:

gsettings set org.gnome.desktop.background picture-uri file:////home/user/image.jpg

Here’s a small script for automatically changing the wallpaper every 60 seconds (just change the sleep 60 value to another value, in seconds). Although not very elegant, it will do the job (please suggest something better here):

#!/bin/bash

while [[ 1 -eq 1 ]]; do
for i in $(echo /usr/share/backgrounds/*.jpg); do
        echo $i
        gsettings set org.gnome.desktop.background picture-uri file:///${i}
        sleep 60;
done
done

This script will automatically cycle between all the .jpg wallpapers in the directory /usr/share/backgrounds/. Just replace it with another directory if needed.

Special thanks for this and this.

Finch
Based on libpurple, Finch is developed by the Pidgin project, and it pretty much supports the same features of it, except for the graphical part, of course. There are many chat protocols which it supports, including AIM, IRC, MySpaceIM, WLM, SILC, Yahoo! or ICQ.

Finch allows you to change the status, report idle time based on keyboard activity or turn it off, it supports plugins, file transfers, sounds, status messages, chat timestamps, customization of the contact list. In addition, it also lets you change and remembers the position and size of the windows.

The very nice thing is that once you get to know how to use it, Finch becomes a great tool for getting the job done.

Finch plugins

Several plugins can be configured and some of the plugins that come bundled with Finch by default include:

• Autoaccept – auto-accept file transfer requests from selected users
• Buddy Notes – store buddy notes
• Grouping – provides alternate ways to group buddies in the contact list
• Join/Part Hiding – hide join/part messages in large rooms

For using Finch you can find a comprehensive guide that I wrote a while ago following this tutorial. This page on the official homepage may be of help too.

Some of the basic keyboard shortcuts include Alt+Q to quit, Alt+A to open the options window, Alt+N to switch to the next window, Alt+C to close current window, Alt+R to resize a window, Alt+M to move a window, Tab to switch through options and Space to tick/untick an option.

CenterIM
CenterIM is another powerful IM client which is being actively developed, and supports the following protocols: ICQ, Yahoo!, WLM, AIM, IRC, Jabber, Gadu-Gadu and LJ.

When it starts, CenterIM shows a configuration window with various general options that can be changed or toggled by pressing Enter. The window that follows allows you to set up accounts for all the supported protocols.

CenterIM provides a default interface with the contact list to the left, and the discussion windows to the right. The online contacts are separated from the offline ones. I tried it using the Yahoo! protocol, and the contact groups seem to be ignored. After writing the text you want to send, press Ctrl+X to send it. Use the Escape key to switch to the contact list and Q to quit CenterIM.

Configuration window

CenterIM supports aways messages, anti-spam features, windows size configuration, keyboard binding, logs, aways system.

One feature which I found to be great is the possibility to enable Emacs/Vi keyboard bindings in the text editor, this making it easy for a person who is used to one of these ways of text input.

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.

finch
Finch comes bundled with Pidgin, the popular IM client. Finch offers the same functionality that Pidgin offers, only that it does it in a terminal by using the ncurses library. It supports IM protocols like Yahoo, Google Talk, XMPP (Facebook), WLM (Windows Live Messenger) and more. A while ago I put up a detailed guide to Finch, which you can read here.
Homepage

htop
htop is an interactive process viewer tool using ncurses which has the great benefit that it allows to scroll up and down the list of processes, and it also uses graphs and colors. I think all these make htop a real gem for the Linux user.
Homepage

irssi
Very powerful IRC (Internet Relay Chat) client with an ncurses-based interface, implements multi-server support, can be expanded with Perl scripts, supports themes, DCC chat and every other possible feature IRC servers allow.
Homepage

mc
Midnight Commander is the famous twin-panel file manager for the Linux terminal, also based on ncurses and with lots of features.
Homepage

lynx
lynx is a popular web browser for the terminal. It supports protocols like HTTP, FTP or Gopher.
Homepage

gzip
gzip is a command-line tool for compressing and uncompressing files. All the files that end in a .tar.gz extension are archived with tar and compressed with gzip.
Homepage

bzip2
Same as gzip, bzip2 is a data compressor which takes a longer time to compress and uncompress files, but it also provides a more efficient compression algorithm which results in smaller files.
Homepage

tar
This tool is used to create archived files, and will also work in conjunction with gzip or bzip2. The command to compress a file or folder to gzip is (what follows after # is a comment):

tar -czf output_file.tar.gz input_file # compresses the file input_file into output_file.tar.gz
tar -czf output_file.tar.gz input_dir # compresses the directory input_dir to output_file.tar.gz
tar -czf output_file.tar.gz file1 file2 file3 # compresses file1, file2 and file3 to output_file.tar.gz

The c argument means compress, the z specifies the type of file to create (gzip file in this case), and f specifies the output file name. The command to uncompress a .tar.gz file:

tar -xzf input_file.tar.gz

This will extract the contents of input_file.tar.gz to the current working directory. Here are the commands for bzip2:

tar -cjf output_file.tar.bz2 input_file # compress input_file to output_file.tar.bz2
tar -xjf input_file.tar.bz2 # will extract input_file.tar.bz2 to the current directory

Homepage

aaxine
aaxine is a video player for console based on xine-lib multimedia player, using ASCII characters for video output. In Ubuntu it is provided by the xine-console package.
Homepage

…it’s Big Buck Bunny by the way

aview
This tool allows to view images as ASCII art. It only supports the following formats, which are either in binary form or ASCII plain text: PNM, PGM, PBM, PPM. It also supports FLI and FLC video formats.
Homepage

mencoder
mencoder is a powerful video encoder and decoder included in MPlayer and can convert between various video files.
Homepage

ffmpeg
Using libavcodec, ffmpeg is yet another powerful tool to encode/decode, record and stream video files.
Homepage

convert
Included in ImageMagick, convert is a tool that can convert between image formats, and also apply various effects to images or edit certain aspects, including resizing, cropping, blur or dither effects. convert is also used on web servers for image processing.
Homepage

moc
moc (music on console) is yet another ncurses-based music player for the terminal which plays formats like Ogg Vorbis, FLAC, MP3, WAV or WMA. It also supports themes and searching for files.
Homepage

The guide explains the basics of manipulating audio files in command-line mode, as well as converting to and from various audio formats, with an accent on the free formats FLAC and Ogg Vorbis. Here are the topics covered:

Introduction to Audio Manipulation on Linux
The Setup: Tools That We Need
Converting FLAC to WAV and Vice-Versa
Converting FLAC or WAV to Ogg Vorbis
Editing Ogg Vorbis Tags
Converting FLAC or WAV to MP3
Ripping Audio CDs
Split FLAC, WAV or APE With a CUE File
Converting WMA to Ogg Vorbis
Converting APE to Ogg Vorbis or MP3
Converting AC3 to WAV Using MPlayer
Music Players

Please feel free to use the comments below for suggestions or corrections and help me improve this guide.

The guide covers the following topics:

What Is Linux?
Basic Commands and Concepts
Moving Around
More Useful CLI Commands
The Power of the Shell
Creating and Editing Files
Linux Directory Structure
Environment Variables
Bash built-ins
Pipes and Redirecting Output
Getting Help
Helpful Links & Further Reading

This is the first release so more improvements and corrections will be added, as well as new chapters.

If you have suggestions or corrections to this guide, please feel free to use the comments below.