Archive for May, 2016

[mc] switch between horizontal and vertical panels

In Midnight Commander it can happen that a filename is too long and thus it is truncated. But still, you would like to see the complete filename.

switch from vertical to horizontal layout with Alt + ,

drawing trees / graphs easily

You want to draw a binary tree / graph quickly. You’ve already used graphviz but you forgot its DOT language and you don’t want to read its documentation again. What do you do?

I found a nice Python project that does exactly this: pygraph.

Command to execute:

$ pygraph -u -e neato circle ab bc cd de ea

Output (circle.png):

See the project’s page for more examples and figures.

I sent a request to the author and he was kind to implement the --dot option that prints the .dot source in a file. This way you can easily tweak your graph. Don’t write the .dot file from scratch: do it quickly with pygraph, get a basic source, and refine it manually if necessary.

Categories: python Tags: , , ,

compile and try a Go project on GitHub

I found an interesting Go project on GitHub ( that I wanted to try. How to compile it?

(This project “pxl” can display images in the terminal).


GOBIN=$(pwd) GOPATH=/tmp/gobuild go get

Under Manjaro I had to install the package “gc”, which contains the official Go compiler.

Categories: bash Tags: , ,

redis: list all the keys

You want to list all the keys in your Redis database. Or, you want to list just some of them.

See the documentation here. Example:

$ redis-cli> KEYS jabba*
1) "jabba:cnt1"
2) "jabba:cnt2"> KEYS *
1) "jabba:cnt1"
2) "jabba:cnt2"
3) "others:counter"
Categories: bash Tags: ,

How to update a GitHub forked repository?

Categories: Uncategorized Tags: , , ,

Upgrade from Ubuntu 14.04 to 16.04

On my laptop I upgraded my Ubuntu to 16.04 but after the restart I didn’t get the graphical interface. The booting stopped and I found myself in a maintenance shell. I also got messages about some hard disk errors.

Well, I also have Windows 8.1 on this laptop and the Windows didn’t do a complete shutdown. Windows 8 does some tricky shutdown to boost the booting process, so it does some kind of half-hibernation. When I used Ubuntu 14.04, I got a message that one partition couldn’t be mounted, “press S to skip”. And I upgraded to 16.04 like this. And this unmountable partition caused this trouble.

So the solution was the following: start Windows 8.1, disable that shitty “fast startup” (see this post for more info), and restart Ubuntu. This time Ubuntu 16.04 booted normally.

Update (20160526)
I upgraded two more machines, there were no real problems. Libreoffice didn’t want to start on one of them, it dropped a “General I/O” error. Here is the cure:

$ sudo apt-get remove --purge libreoffice*
$ sudo apt install libreoffice

It’s a good idea to use “apt” instead of “apt-get”. It does the same thing but in addition you get a nice progress bar.

MongoDB stopped too. Here is how to start it with systemctl:

$ sudo systemctl enable mongodb
$ sudo systemctl start mongodb
# verification:
$ systemctl status mongodb
$ mongo

how to install Neovim under Ubuntu

Under Manjaro I installed neovim with yaourt. It installed version 0.1.4 and it works fine. For Ubuntu, the home page of Neovim suggests a PPA but it installed for me the version 0.1.5-dev, which is a development version.

How to install a specific version under Ubuntu (namely 0.1.4 in this case)?

Visit and find the tagged version 0.1.4. Download the zip, uncompress it, and enter the project folder.

Install the dependencies:

$ sudo apt-get install libtool autoconf automake cmake libncurses5-dev g++

Build and install the project:

$ make cmake
$ make test
$ sudo make install

It’s a good idea to install the “neovim” Python package too:

$ sudo pip2 install neovim
$ sudo pip3 install neovim

Tips taken from here.

Update (20170402)
There is a PPA now for neovim stable. Use that: .

How to use powerline fonts under Ubuntu? Install the patched fonts: . Then, if you use konsole, go to its settings and select one of the patched fonts. Currently I use the Hack font.

Categories: ubuntu, vim Tags: , , ,