Archive for the ‘Uncategorized’ Category

Dropbox: .html files in your Public folder are no longer rendered in the browser

October 4, 2016 Leave a comment

Until now I’ve stored a lot of teaching material in my Dropbox’s Public folder that I shared with my students. Here I had a generated index.html file in each folder that one could render in the browser. This way, you could have a static HTML site in your Public folder that you could share easily, and any changes to it were synced automatically.

However, Dropbox changed his mind:

Dropbox Basic (free) users: Beginning October 3, 2016, you can no longer use shared links to render HTML content in a web browser. If you created a website that directly displays HTML content from your Dropbox, it will no longer render in the browser. The HTML content itself will still remain in your Dropbox and can be shared. Learn more.

Dropbox Pro and Business users: Beginning September 1, 2017, you can no longer render HTML content.” (source)

The good times are over :(

I faced this problem this morning and I started to look for an alternative. A friend of mine, Füli, suggested that I should move to And that’s what I did :) In an hour the migration was done. Here is the result:

Congratulations, Dropbox, you managed to kill one of your most attractive features…

Categories: Uncategorized Tags: , ,

Bitbucket: create SSH key, upload SSH key

August 4, 2016 Leave a comment

GitHub is very good for open source projects, I also use it. However, if you want to work on a private project alone or with some of your friends and you don’t want to share the code, then Bitbucket could be a better choice since it allows you to create unlimited number of private repositories.

You are at a new machine of yours. You create a new repository, clone it on your localhost, make some changes, and when you try to push the changes to the repo, you get an error message that you should upload your SSH key. How to do that?

Check if you have an SSH key:

$ cat ~/.ssh/

If you don’t have an SSH key, create one:

ssh-keygen -t rsa -b 4096 -C ""

Accept the default file location and provide a passphrase.

Then copy the content of “~/.ssh/” to the clipboard and add it to your account by following these steps.

Categories: Uncategorized Tags: ,

show my position on the map

June 21, 2016 Leave a comment

The site gives you back not only your IP address, but your geolocation too. Example (with a fake IP):

$ curl
  "ip": "734.675.653.542",
  "hostname": "No Hostname",
  "city": "Debrecen",
  "region": "Debrecen",
  "country": "HU",
  "loc": "47.5333,21.6333",
  "org": "...",
  "postal": "..."

Let’s visualize my location:

<img src=",21.6333&zoom=9&size=480x240&sensor=false">

Debrecen, Hungary, center of the world :)

Categories: Uncategorized Tags: , , ,

How to update a GitHub forked repository?

Categories: Uncategorized Tags: , , ,

[vim] I’m back to (neo)vim

May 15, 2016 2 comments

A week ago I returned to vim, more precisely to neovim.

Here is my story…

When I started the university (geez, that was 20 years ago) we got an account to a Unix server. On the first week I logged in and launched Midnight Commander. I wanted to check out the content of a file in my HOME folder so I pressed F3 (view) on it. However, the default editor was “vi” :) I had no idea how to quit this program so I had to ask a senior student in the lab to help me. He was kind and showed me the trick: “:q<Enter>“. So this is how I met vi and after this I avoided it for 3 years. Then I had a Java class where there was a guy who was a big zero in programming. One day he was sitting next to me and he was using Vim! And I was using Joe. He had nice syntax highlighting and he showed me some vim tricks. And I thought “WTF? If this guy could learn it, then I can learn it too.” I asked him about it and he told me that he started it with the command “vimtutor“. I went home and that very afternoon I went through the vimtutor too. I made some notes but I couldn’t memorize all those keyboard shortcuts. In the next few days I went through the tutorial two more times. Then I forced myself to use vim for all my text editing works and I got to like it. When I needed something I looked up how to do it with vim. The commands were logical and soon it was a pain to use any other editor.

Several years passed and I was very satisfied with Vim. I wasn’t a guru and I didn’t use many plugins, but I could solve all my problems with it. Then 2 years ago I heard that Emacs can be vimmified with the Evil plugin. I gave it a try and it was like a “better vim”. It had a nice GUI, I liked its default color scheme, it had a plugin manager, etc. I spent two weeks with its configuration and I could reproduce the majority of my vim settings. It was good.

I have several machines (desktops, laptops) and I used Emacs+Evil everywhere. I keep my settings in Dropbox, so I have the same configuration on all my computers. However, on my older machines Emacs started very slowly. Sometimes I had to wait 20 seconds! So when I wanted to edit a little script, I just launched vim. And it happened more and more often…

And now it’s present time. Two weeks ago I read about Neovim and I liked its features: a modernized vim, async job control, built-in terminal. I decided to give it a try. I created an empty init.vim file (it’s Neovim’s .vimrc equivalent) and transferred from .vimrc the necessary things. It turned out that my .vimrc had lots of obsolete settings that I could drop. On the forums I looked after the popular plugins. I even started learning vimscript :) Now my settings are better than my old Vim settings. I like Neovim and I am going to use it from now on.

If you are interested, then here is my init.vim configuration file for Neovim. It’s a work in progress but it’s already usable.

Expect some (neo)vim posts in the future :)

Categories: Uncategorized, vim Tags: , , ,

listen to Pandora Radio, even if you are not a US citizen

April 21, 2016 Leave a comment

If you are a peasant like me living outside of the US but you still want to listen to Pandora Radio, which is only available in the center of world (USA), then what can you do?

There is a very simple solution now. Opera offers free VPN, built directly in the browser. You can choose between German, Canadian or American VPNs. Currently this feature is only available in the development version of Opera. So here are the steps:

  1. install Opera (development version)
  2. install Flash player for Opera (Pandora is a Flash-based website)
  3. visit just to see that you are kicked out
  4. enable VPN: with Alt+P you can access the Settings, go to Privacy & security, then enable VPN
  5. Open an arbitrary site. On the left side of the URL bar you’ll see that VPN is activated. Click on it and select United States.
  6. Visit again. Strangely, you are let in this time…

hacking with URL shorteners

April 18, 2016 Leave a comment

This article ( just gave me an excellent idea…

In a nutshell: these URLs are so short that you can explore a lot of them with a simple brute force approach. Just generate a random hash and there is a high chance that it points to somewhere.

Example: with I generated a link: . I tried to modify some characters in the hash and in most cases it pointed to somewhere…