I was just cleaning up my desktop and came across a snippet I had saved which removes a specified folder from a Git repository including removing it from the history of the repository. In general, if something was committed to a repository, you shouldn’t remove it from the history, but there are cases where it makes sense – perhaps a sensitive password or key was unintentionally commited.

The command is pretty simple, but be warned that it can have grave consequences if you remove the wrong thing:

git filter-branch --force --index-filter \
'git rm -r --cached --ignore-unmatch .idea' \
--prune-empty --tag-name-filter cat -- --all

git push origin master --force

In the example above, I removed the default .idea folder that is included with JetBrains IDEs like IntelliJ and Pycharm.

There are several options for running a Raspberry Pi operating system on a 2GB SD card, but in the this blog post I’d like to talk about how to install the ‘official’ distribution, Raspbian, on a smaller SD card. This method requires the minimal Raspbian Unattended Netinstaller which can be found at the following link:

The readme file that is shown on the base GitHub project linked above covers the basics of installing the operating system which I will briefly touch on here and the cover a few additional configuration options I choose to do. Some of the key things I like about the raspbian-ua-netinst project is that it fits on a 512 MB card, it downloads the required components through an internet connection via the Ethernet port, and it can do all the hard work completely unattended.

At a high level, here is what is needed to perform the install. (Reference the github link above for more detailed instructions):

  • Grab a 512 MB or larger SD card
  • Download the 10 MB installer package
  • Format the SD card as FAT32
  • Unpack the installer archive
  • Copy the unpacked files to the SD Card
  • Plug the SD card and a network cable into the Pi
  • Power up the Pi and let it install (this is the unattended part mentioned above)

A summary of my findings with the Stick-N-Find stickers and their usability as an iBeacon / Bluetooth LE proximity device. I ordered a set of Estimote Beacons and Stick-N-Find stickers and have been playing with automation concepts within Android. In particular, I wanted to be able to have my Android device understand the proximity to a location and have a general understanding of indoor positioning.

Note: If you just want to know how to Configure your Stick-N-Find for use in Tasker, jump to Configure as iBeacon

Stick-N-Find Beacon and iPhoneEstimote iBeacon

I recently started working with the integrated Version Control System (VCS) features of PyCharm and accidentally pushed my IDE / PyCharm project settings to my Google Code hosted Git repository. Basically, all of the files in the .idea folder of my project were pushed to the repository. While these files didn’t necessarily contain any proprietary or confidential information, I didn’t want them cluttering up my project repository. And while I could have simply removed the files and performed a commit, these files would have then been in the history of my repository.

I did some quick research and found a post on GitHub explaining how to remove a file along with its history from a GitHub repository. This command basically did what I needed to, but was designed to remove a single file at a time. Being that I wanted to remove a whole directory of files, I modified the command to remove the folder and recursively iterate through the directory removing children:

git filter-branch --force --index-filter \
'git rm -r --cached --ignore-unmatch .idea' \
--prune-empty --tag-name-filter cat -- --all

git push origin master --force

It should be noted that the command will overwrite existing tags and that if you had sensitive information in the files (like passwords), you should consider the information compromised and take appropriate action.


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About Me

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Name: Joshua Lyon
Birthday: August 8, 1985
Location: Valley Ranch (Irving), TX
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
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