Today I was setting up Windows Subsystem for Linux and wanted to change to the root user using the command:
su -
I was prompted for the password, but had no idea what it was. So I needed to figure out another way of switching to the root user instead of prefixing every command with sudo. Did I say switch and prefix and sudo? O yes, stupid me.
sudo su
Don’t forget to exit once you are done. And be careful not to wrech havoc while working under the root account. Have fun!
Today I needed to validate a json file on one of my servers. It turns out there is a simple nodejs program or actually a linter to do this with.
Just execute the following line and you are in business.
sudo npm install jsonlint -g
This assumes nodejs is already installed. If not, execute the following line.
sudo apt-get install -y nodejs npm
To validate a json file run the following command.
jsonlint -qc settings.analyzer.json
When running the program the first time I ran into the problem that the json file contains comments. Yes, I know this is not in line with the spec, but it is damn handy for understanding the file. So I needed to strip the comments to valiate the file. After googeling around a bit I found an awk command to do just this. Try the following command.
awk '{sub(/\/.*$/,"")}1' settings.analyzer.json > settings.analyzer.json
Now run jsonlint again and it should work.
P.s. I know the title of this post says Linux, but jsonlint will also work under any other system that nodejs runs on.
Hope this saves someone some time.
TD;LR
In this post I will explain how to install, configure and run PT Magic (PTM), a free add-on for the Profit Trailer (PT) cryptocurrency trading bot, on a VPS using Ubuntu. As an extra security precaution the PTM GUI is only accessible through a SSH tunnel using PuTTY with port forwarding. This avoids opening additional ports on the VPS to the outside world.
In this post I will explain how to install, configure and run Profit Trailer (PT), a cryptocurrency trading bot, on a VPS using Ubuntu. As an extra security precaution the PT GUI is only accessible through a SSH tunnel using PuTTY with port forwarding. This avoids opening additional ports on the VPS to the outside world.
In this post I will explain step by step how to install and setup Gunbot 7.0.2 and Zeno GUI 1.31 on Ubuntu 17.10. It also shows how to access the Gunbot GUI and Zeno GUI through a SSH tunnel using PuTTY with port forwarding for enhanced security. A no thrills quick and dirty write-up.
Who still uses Microsoft Silverlight? UPC… They use the Silverlight plugin to stream TV and handle DRM. Okay, that’s nice, but how do you get Silverlight to work under Linux? It turns out it is a few easy steps using Pipelight which brings support for Silverlight to Firefox and Chrome under Linux. Continue reading
Using the bash shell you can create multiple directories with a single command.
Relative to the current directory:
mkdir ./{project,target}
Relative to a path and create any parent directories that do not exist:
mkdir -p ~/git/myrepository/{project,target}
I needed to find out where the Oracle JDK 7 was installed. Using the whereis command did not help. I found that using the following command shows exactly where all available JDKs are installed:
sudo update-alternatives --config java
I am currently learning Scala and wanted to install the Scala IDE. In the process I ran into some problems that it programs would not compile correctly, which seemed to be caused by the OpenJDK 7. So I decided to remove OpenJDK 7 and install Oracle JDK 7. All the instructions I could find to do this where downloading based on manually downloading the Oracle JDK 7 and installing it interactively. As I also wanted the installation to work in a Docker container I wanted a fully automated solution. Continue reading
Had an interesting time figuring out how user and group management works from the command line on my QNAP server. At first the usual Linux commands do not seem to exist:
useradd usermod userdel groupadd groupmod groupdel
After some Google research (who’s your friend?) I found some forum posts that pointed out the commands have been replaced by QNAP’s own special versions: Continue reading
Adventures of a space monkey 