Raspberry Pi As Security Camera With Motion Detection

It was a fun weekend project I did with my kids. We started with a new Pi Zero and in a few hours (of many ‘paths’ to nowhere) we got into the point of having a useful security camera. The useful part is when the camera sends you alerts (email or Telegram messages) when it detects movements.

We open the package and connected the Pi Zero to a USB power, a keyboard, a mouse and monitor. We cut a bit a corner by buying an SD card with NOOBS on it but it wasn’t working (nothing was coming up on the screen when we boot the Pi). So we downloaded a new version from Raspian Jessie 4.4 from NOOBS and install it. Now when we boot the Pi we got a new screen. We open the terminal and typed:

Continue reading

Add Users to Google Compute Engine / EC2 Instances

KeysIn the past, when I wanted to share a Linux box with other users, it was simply by creating another user and making sure their password are ‘strong’. These days, it’s much safer not to use passwords over ssh but rather keys in order to connect (over ssh) to your machines in the cloud.

Here is the full list of commands you need to do in order to add a user. It’s being tested on Ubuntu so if you are on another OS, please continue with caution.

[gist f949f215b405d2d767b3]


Chrome, HTML5, JavaScript, webdev

Install Ubuntu On Your Chromebook

chromebook 5

Chromebook For Developers And Hackers

If you are a Linux hacker and/or a developer with a new Chromebook, Chromebox, Pixel or an old laptop with ChromeOS… You might want to have the ability to have a dual-boot option that will let you enjoy the power of your ChromeOS but on the same time be able to boot your laptop with Linux and enjoy C, C++, Java and the fun technologies. It might be hard on other platforms to ‘hack’ them, but since the chromium project is open-source, I guess, they wanted to be hackable by design (e.g. you have a keyboard shortcuts in Pixel that let you enter this mode). Here are the few steps you need to follow in order to enjoy hacking ChromeOS. Continue reading

Chrome, HTML5, webdev

ChromeOS Hacking On Google Developers Live Israel

ChromeOS - new gift to your old laptop

ChromeOS – A new gift to your old laptop

Today, I had the pleasure to sit for 15min with Nissim Betito (the one and only!) how is a known hacker in the linux community around TLV. We spoke about Chromebook and what are the powerful tools that you can leverage today when you wish to write code. Later, we showed how to install ubuntu on Chromebook and get everything you miss as a developer that must have gcc (or other complier) under their hands. In the near future we will show how to install chromeOS image on raspberry pi… Continue reading


Linux Bash – Shortcuts To Boost Your Productivity

Let’s face it… in most of the cases (in the end of the day or night) you will be on a linux shell trying to hack some last minute changes to ‘production’. Ya… you know it’s something you should not do, but life is stronger than anything, no?
Here are few shortcuts to help you finish your day:

Command Editing Shortcuts

  • Ctrl + a – go to the start of the command line.
  • Ctrl + e – go to the end of the command line.
  • Ctrl + k – delete from cursor to the end of the command line – save you lots of time.
  • Ctrl + u – delete from cursor to the start of the command line, I’m not using it, but still a good one.
  • Ctrl + w – delete from cursor to start of word (i.e. delete backward one word)
  • Ctrl + y – paste word or text that was cut using one of the deletion shortcuts (such as the one above) after the cursor
  • Ctrl + xx – move between start of command line and current cursor position (and back again)
  • Alt + b – move backward one word (or go to start of word the cursor is currently on)
  • Alt + f – move forward one word (or go to end of word the cursor is currently on)
  • Alt + d – delete to end of word starting at cursor (whole word if cursor is at the beginning of word)
  • Alt + c – capitalize to end of word starting at cursor (whole word if cursor is at the beginning of word)
  • Alt + u – make uppercase from cursor to end of word
  • Alt + l – make lowercase from cursor to end of word
  • Alt + t – swap current word with previous
  • Ctrl + f – move forward one character
  • Ctrl + b – move backward one character
  • Ctrl + d – delete character under the cursor
  • Ctrl + h – delete character before the cursor
  • Ctrl + t – swap character under cursor with the previous one

Command Recall Shortcuts

  • Ctrl + r – search the history backwards
  • Ctrl + g – escape from history searching mode
  • Ctrl + p – previous command in history (i.e. walk back through the command history)
  • Ctrl + n – next command in history (i.e. walk forward through the command history)
  • Alt + . – use the last word of the previous command

Command Control Shortcuts

  • Ctrl + l – clear the screen
  • Ctrl + s – stops the output to the screen (for long running verbose command)
  • Ctrl + q – allow output to the screen (if previously stopped using command above)
  • Ctrl + c – terminate the command
  • Ctrl + z – suspend/stop the command

Bash Bang (!) Commands

Bash also has some handy features that use the ! (bang) to allow you to do some cool stuff.

  • !! – run last command
  • !blah – run the most recent command that starts with ‘blah’ (e.g. !ls)
  • !blah:p – print out the command that !blah would run (also adds it as the latest command in the command history)
  • !$ – the last word of the previous command (same as Alt + .)
  • !$:p – print out the word that !$ would substitute
  • !* – the previous command except for the last word (e.g. if you type ‘find some_file.txt /‘, then !*would give you ‘find some_file.txt‘)
  • !*:p – print out what !* would substitute
Btw, if you are Eclipse power user and with to have bash inside it:
  • Go to Menu Run/ External Tools / external  Tools
  • Click on Config (or on Mac – Add external tools) then on ‘Program’ (inside the right sidebar) and select ‘new’
  • in the Name field, type Bash
  • In location type /bin/bash
  • In argument type -s -i
  • In the common tab check ‘Allocate Console’ if it’s not
  • Click on Apply
  • Then you just have to click on the External tools icon and select ‘Bash’ – Done.