Karabiner-Elements: Right-Alt + j to í

A complex modification rule for Karabiner-Elements to change AltGr + j to í. Install Karabiner-Elements from here Click here to import the rule Alternatively, open [...]

Disable iTunes Keyboard Shortcuts/Media Buttons on macOS

UPDATE FOR SIERRA 10.12.4 AND UP This only works on macOS versions prior to macOS Sierra 10.12.4 (16E195) as starting from this version it is necessary [...]

Find and reattach a lost terminal screen session under Linux / Mac OS X

Running lengthy operations (such as remote sync, video compression) is preferred to be done in a screen session: among other things, it enables you to [...]

Disable MobileBackups local Time Machine backups on Mac OS X

Being on the road (or just away from your Time Capsule) for longer periods of time may cause a surprising dent on your free disk [...]

Extract single file/directory from tar gz archive

Doing automated backups is a must for every sysadmin worth its’ salt. If you happen to administer a smaller pool of servers/hosts it is more [...]

VMware ESXi Copy VM from one Host to another without vCenter

There comes a time in every sysadmin’s life when a second Virtual Machine Center is added to the inventory of awesomeness and soon You’ll find [...]

Google SMTP Error PTR 550-5.7.1 IPv6 - Fix for Postfix under Ubuntu Server

Having undelivered mails due to numerous errors is not nice – having all of our sent emails rejected by a particular host is nothing short [...]

Shared Folder disappeared in Veertu - Windows 7 Fix

After a recent upgrade to the Veertu virtualization software, many users – including myself – have been surprised to find out that the Shared Folder [...]

How to hide terminal command output messages under ubuntu / debian linux

There are times when we do not want our scripts or programs to outputy any kind of message to the standard output – like for [...]

Ubuntu LTS 14.04 Server Router From Scratch

Building your very own Ubuntu Server from Scratch is as great way to get a grasp at how things work under the hood, not to [...]

Measure network speed, throughput performance and bandwidth between devices

It is always good to know just how much TCP / UDP packets can we squeeze out from our network interfaces. Be it that we [...]

MikroTik RouterOS Hairpin NAT - Public WAN Port Forward From LAN

Switching from a cheaper brand router to something classier can cause a lot of surprises: from broader set of functions to unforeseen security options. One [...]

Upgrade rsync on Mac OS X

By default, Apple decided to ship version 2.6.9 of rsync with Mac OS X 10.11 El Capitan. For the most part it gets the job [...]

Slow SSH Login in Debian / Ubuntu Linux

Generally speaking, even the password prompt should not take a lot of time (more than a few seconds) to pop up during the initial connection [...]

RTNETLINK answers: File exists

Editing config file for the network interfaces in a breeze – unless you make all the necessary edits, save then quit editing, restart your networking [...]

Ubuntu Server LTS restart networking

Those of you who have been using service networking restart to re-cycle your network interfaces will surely be surprised, when the command prompt spits back an error [...]

Ubuntu Linux AIDE Setup - Advanced Intrusion Detection Environment

Having anti-virus software and a rigorous firewall as your first line of defense is considered a bare necessity nowadays. But what happens when somehow the [...]

Remove Xcode Junk from Mac OS X

Oftentimes we find ourselves in dire need of some extra disk space. Given the chance that you do a lot of iOS / Mac OS [...]

Disable and Remove Windows 10 Notification Icon

Open Control Panel, go to Windows Update and click on Change Settings on the left pane. Now change the option in the drop-down list from “Install updates automatically (recommended)” [...]

Ubuntu VPS UTF-8 locale error

Setting up a VPS in the cloud is the current de facto method of launching services for startups and bigger companies alike. Supposedly, when someone [...]

Enable built-in FTP server in Mac OS X Yosemite / El Capitan / Sierra

Open up a Terminal and paste in the following commands to enable or disable the built-in FTP server. To turn on the FTP server, paste [...]

Convert Videos to iPod / iPad / iPhone with FFmpeg under Ubuntu or Mac OS X

We’ll pretend you have ffmpeg up and running, with the necessary build options – for more info on that, refer to the FFmpeg Compilation Guide. [...]

Converting/Encoding x265 under Mac OS X with FFmpeg

Suppose that we have our brew up and running and we’d like to do some video conversion, namely something to x265. To do this, first [...]

Grep whole directory recursively by file extension only

Using grep to scan thru a whole directory recursively is done with: grep -R 'string' dir/ In addition, you can also tell grep to only [...]

Crontab / User cron file location in Ubuntu

Usually you shouldn’t edit these by hand, but given the off-chance you’d want to, cd yourself all the way to: /var/spool/cron/crontabs If per chance you’d [...]

See Mac OS X FileVault 2 Encryption Progress in Terminal / CLI

Pop open your Terminal.app, type in the following and hit Return: diskutil cs list |grep -e 'Conversion Progress' Be cautious as between the pipe sign [...]

Find and Block Abusive IP Addresses on Ubuntu Server

The Issue Your server has an extremely high workload in comparison to the usual CPU load, it generally feels less- or even unresponsive and if [...]

OpenWRT Wi-Fi Repeater / Wireless Bridge

Let us have a nice Wi-Fi range extander be born from the ashes of a long discarded router now, shall we? I’m going to assume [...]

Sublime Text C++/CPP Build System under MacOSX Yosemite

Using the ever-so-wonderful Sublime Text as your primary editor is a joy in itself, however, building your .cpp files under OS X with it was [...]

Transmission on Ubuntu Server 14.04 with Flexget - Python error fix included!

First, let’s install Transmission and set up some directories – issue these commands (remember to substitute user with your desired username that runs transmission) sudo [...]

Ubuntu Command Line - How To Connect To Wi-Fi WPA/WPA2

  First and foremost, you will need to have wpa-supplicant installed, otherwise it won’t work. Ubuntu does installs this be default, but to be on [...]

BizHub 250/350 Duplex / Double Sided printing on Mac OS X

At the Printing options select Finishing > and tick in Duplex.

Problem with libstdc++-libc6.2-2.so.3

Ever encountered the following unpleasant error message under Debian or Ubuntu?   error while loading shared libraries: libstdc++-libc6.2-2.so.3: cannot open shared object file: No such [...]

Remove file protection from copied files under Mac OS X

Copying files from read-only media or an external drive (or even a network share) can cause them to become “protected” upon being written to disk [...]

VNC from the Login Screen: accessing the actual Ubuntu X Display shown on the monitor

Issue the following command with elevated rights or as root: apt-get install x11vnc   Create the file /etc/init/x11vnc.conf with your favourite text editor and write this [...]

ProFTPd error in Ubuntu 12.04 - solution!

By default, the installed package refused to start, because of missing files. So I had to do the following to resolve the missing links:   First, [...]

Scrolling within Mac OS X Terminal app

Ever wanted to scroll pushing Shift + Page Up/Down within Terminal.app? Here is how to do it, check MouseTerm!    

Updating Darwin Ports / MacPorts on OSX Mountain Lion

  1. Let’s update the currently available application package list /opt/local/bin/port -d selfupdate   2. Darwin ports should be updated as well: /opt/local/bin/port upgrade outdated [...]

Coda 2 is not saving passwords for FTP servers

The gurus over Panic have made Coda 2 one of the very best development tools for Mac OS X, stuffed with all the features one [...]

How to close open SAMBA / Windows Shared Folder connections effectively

Since the concept of mounting a file system had risen, nearly every type of media and storage device can be accessed from practically everywhere in [...]

Excel 2007 / 2012 - Open two spreadsheets in two separate windows

Ever wanted to open a spreadsheet like you did before Excel 2007? Now it is possible and it comes in handy if you need to [...]

Android - the Missing Manual

1.Resource specification should not include the file extension! Example: “drawable/icon.png” should be referenced as “@drawable/icon”  

Android SDK Error under Ubuntu 12.04 "Precise Pangolin" 64-bit - AVD Emulator Failed to load libGL.so

Doing some Android bloodshedding with the good ol’ Tux gives an undescribable feel in elaborating your carefully crafted lines of code…so does an error message [...]

Remove unused kernel header files in Ubuntu

Straightforward, constant updating is the key to have a fresh and bleeding edge Ubuntu system. However, for those of you who are strapped for disk [...]

Modifying Debian/Ubuntu Startup Programs from CLI / Terminal

Ever wanted to modify your list of custom-added applications from perhaps a remotely logged in shell? Well, there is really not much to it, as [...]

VNC with SSH-tunneling over PuTTY

Having SSH is totally great to administer your servers and such, but if you ever face a situation that absolutely requires a few clicks to [...]

Subnetting, VLSM and Cisco

Useful links on the subject:   http://www.subnettingquestions.com/ http://www.learntosubnet.com/ http://www.semsim.com/ccna/tutorial/subnetting/subnetting.html http://www.tcpipguide.com/free/t_IPVariableLengthSubnetMaskingVLSM.htm http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a00800a67f5.shtml http://www.techexams.net/forums/ccna-ccent/19607-vlsm-practice.html http://fengnet.com/book/CCNA%20Portable/ch02lev1sec2.html http://i.i.com.com/cnwk.1d/i/tr/downloads/home/1587201585_chapter_2.pdf https://learningnetwork.cisco.com/thread/9674  

Ubuntu Server 12.04 LTS USB install error, problem reading disc

Making a bootable USB drive off of Ubuntu Server 12.04 LTS is fairly easy and there are even a lot of graphical tools available to [...]

Bash Completion on Ubuntu 12.04 LTS - hit TAB to complete your command

As many of you already know, the Linux/Unix command line interface has a neat little feature, that greatly enhances the speed of executing commands (and [...]

Shutdown error in Ubuntu 12.04 LTS Server edition

Many of us have experienced that after updating to Ubuntu Server 12.04 LTS, the halt command seems to do partial job: it really does halt [...]

Upgrading Ubuntu 12.04 LTS upgrade from console/terminal

Upgrading our Ubuntu Linux installtion (be it 10.04, 10.10, 11.04 or 11.10) can be fairly easy with the aid of the graphical update manager tool. [...]

Regaining user access after restoring a PostgreSQL backup made with dumpall

Usual, frequent backups – containing just about everything – are highly favoured by a wide-range of sysadmins. In some scenarios, it is more than enough [...]

WPA/WPA2 WiFi password cracking - Reaver on Ubuntu 12.04 LTS

A short, straightforward guide to install and set up Reaver on Ubuntu 12.04 LTS – found and archived from this website, should it be moved [...]

MikroTik RouterOS Password Recovery

Forgetting a long – usually pwgen generated – password can truly be a pain. There are numerous methods of circumventing the password authentication protection, what [...]