Find 20 Largest Files on your system

Running out of Disk Space ?
want to see which files are the largest files on your system and are contributing to filling up your hard disk.
Copy and paste the following command into your terminal. and run it in your root directory.


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


This will  list the 20 Largest files on your System, and report their size in human readable format.

better still, copy and paste the line into a file,
name the file bigfiles
save the file in /usr/local/bin
chmod +x /usr/local/bin/bigfiles
then from anywhere on your system simply type 
bigfiles

Pimp your Tail command

The default settings of the TAIL command is to output the last 10 lines of a file

eg 

tail /var/log messages

will output the last 10 lines of your /var/log/messages file

Mar 24 11:25:20 mirage dbus-daemon[1094]: dbus[1094]

Mar 24 11:25:20 mirage dbus[1094]: [system] Successfully activated service 'org.freedesktop

Mar 24 11:27:44 mirage dbus-daemon[1094]: dbus[1094]: [system] Activating service name

Mar 24 11:27:44 mirage dbus[1094]: [system] Activating service name='net.reactivated

Mar 24 11:27:44 mirage dbus-daemon[1094]: Launching FprintObject

Mar 24 11:27:44 mirage dbus[1094]: [system] Successfully activated service 'net.reactivated.Fprint'

Mar 24 11:27:44 mirage dbus-daemon[1094]: dbus[1094]: [system] 

Mar 24 11:27:44 mirage dbus-daemon[1094]:

Mar 24 11:27:44 mirage dbus-daemon[1094]: ** Message: entering main loop

This alias changes the default setting of tail so that it outputs all the lines that can fit on your screen.

just add the following to your .bashrc if you use bash or your .zshrc if you use zsh as your terminal editor.

alias tail='tail -n $((${LINES:-`tput lines 2>/dev/null||echo -n 80`} - 7))'

then source youre .bashrc or .zshrc by typing

source .bashrc or

source .zshrc

or just restart your terminal

next time you run  tail on a file you will get as many lines as will fill up your screen.

play and edit MT2S files

MT2S files are High Definition Sony Blue ray AVCHD Files,
commonly produced by High Definition Camcorders.

To use edit and play these files on your Linux system
Openshot video editor works well as a video editor

yum install openshot or apt-get install openshot

although VLC can play these files you need to make the following changes to VLC so that they play well.

open up VLC


Go to Tools -->Preferences --> Input &  Codecs 
on the option “Skip the loop filter for H.264 decoding” select ALL 
Then in preference window Click Show Settings -> All. and expand Stream Output ->
Click Muxers ->select Mux module as “FFmpeg muxer”

next click

Expand Video -> Select Output module -> In Video Output module and select X11 video output.



and then save your settings

MT2S high definition files should play much more smoothly in VLC now.

Disable top left corner mouse Hotspot in Gnome 3

In Gnome 3, moving your mouse into the top left corner of your screen, simulates pressing (Alt-f1) or the Windows key, and puts you into search mode.  This can be extremely annoying when it happens accidentally.
 I prefer to only use the Keyboard for this feature.

to Disable the Mouse hotspot edit the following file

vim /usr/share/gnome-shell/js/ui/panel.js 


then search for the following line
this._hotCorner.actor.allocate(hotBox, flags);


and comment it out, by putting // infront of it
like so

// this._hotCorner.actor.allocate(hotBox, flags);


save the file, and logout/login to your Gnome session.

no more annoying mouse hotspot.

my .zshrc file

# Lines configured by zsh-newuser-install
HISTFILE=~/.histfile
HISTSIZE=100000
SAVEHIST=10000
setopt autocd
bindkey -v
# End of lines configured by zsh-newuser-install
# The following lines were added by compinstall
zstyle :compinstall filename '/home/cgerada/.zshrc'

autoload -Uz compinit
compinit
# End of lines added by compinstall

#the following lines were added by cgerada
#autocompletion of hostname from ,ssh/known_hosts

local _myhosts
_myhosts=( ${${${${(f)"$(<$HOME/.ssh/known_hosts)"}:#[0-9]*}%%\ *}%%,*} )
zstyle ':completion:*' hosts $_myhosts
#Spelling autocorrect
setopt  correct

#coloured prompt
autoload -U colors && colors
PS1="%{$fg_bold[green]%}%n%{$reset_color%}@%{$fg_bold[blue]%}%m %{$fg_bold[yellow]%}%~ %{$reset_color%}%% "
# right hand prompt simple date and time only
 RPROMPT="[%D,%T]"

#Extension aliases very cool
alias -s doc=libreoffice
alias -s xls=libreoffice
alias -s doc=libreoffice
alias -s pdf=evince

~                                                                                                                                                          
~                          


~                                                                                                                                                          
~                                                                                                                                                          
~                                    

Moving from Bash to ZSH

I have Stopped using Bash and am now using ZSH as my new shell of Choice.
ZSH has many awesome features that make it a No brainer (for me anyway) to make the switch

Here's what I love about ZSH

1:) Your History is shared across sessions. Multiple simultaneously running zsh sessions can share history with each other. how many times have you looked into your bash history to find a recent command that you used, only to find that that command was run on a different terminal session and is no longer available to you.

2:) Tab Auto completion works between remote machines over SSH.

rsync -avr remotemachine:/home/cgerada/Documents/very/long/directory/na (at this point you can hit tab and provided that you connect to your remote host using ssh Key authentication instead of password authentication  zsh will autocomplete for you.

3:)No need to type cd to change into a Directory.
/home/cgerada/directory   enter

will change to /home/cgerada/directory  for you.
Considering how often you use the cd command, this is a real time saver.

4:) Tab auto completion works for command options
     rsync -av (hit tab here) will show you all possible options for the rsync command

5:) Built in Spell check
     How many times have you typed something like aptg-et or other mangled commands? Well,
     if you do that in zsh,You  get a message asking: “zsh: correct 'aptg-et' to 'apt-get' [nyae]? “

6:) Built in pager.
     If your Lazy like me. And I think you are.  zsh comes with a pager directly in the shell. This means you
     can type things like " > README  and it is equivalent to less README or cat README | less"


7:)Right hand prompt
    Zsh supports a second (right hand prompt) great for adding the date and time (see screen shot above)
    or if you own a laptop you can also display your Battery capacity.  The right hand prompt will not get in
    your way as it disappears when your typing reaches it. or you can just not enable it if you don't want it.

8:) Known hosts auto completion. ZSH can even tab autocomplete hostname entries of remote machines that  
     you connect to from your .ssh/knownhosts file.

     in fact auto completion in all areas is far more superior in ZSH.

9:) Extension aliases

alias -s doc=libreoffice





putting the above in your .zshrc file allows you to open up a .doc file simply by typing its filename. eg

officedoc.doc  [enter]

will open up officedoc.doc using libre office (in Bash you would have had to type

libreoffice officedoc.doc
you can do the same for all extensions eg
alias -s pdf=evince
                      
ZSH has loads more awesome features, and is highly customizable .  it behaves extremly similar to bash, in fact you can use it exactly the way you use bash and not learn or change a single thing and you won't be missing anything.

Right, so if you are convinced to make the change and jump right in.

install zsh by typing  yum install zsh or apt-get install zsh.

once installed simply type
chsh to change your shell  .
you will be asked for your user password
once typed in correctly you will be asked
New shell [/bin/bash]
type /bin/zsh   enter

and the next time you log into your shell with your username you will be in the ZSH shell.

If for what ever reason, you do not like zsh and want to revert back to bash
simply type
chsh
enter your password once again
and then type
/bin/bash

will change your shell back to Bash.