Fix mailR java issues

You might have a couple of issues with mailR when running on a server.

When installing or after installing the r package: rJava you might encounter the following: cannot open shared object file: No such file or directory

I fixed this on a ubuntu server with this command: sudo R CMD javareconf

Shutdown Linux Machine At Specific Time

Here is a useful command when you need to shutdown you machine at a specific time of the day. For example after a specific event you needed to log.

shutdown -h hh:mm

Shutdown scheduled for ons 2017-04-12 22:35:00 ICT, use 'shutdown -c' to cancel.

Remark, you can can always cancel the shutdown with "shutdown -c".


shutdown -h 22:35

Get more info with "shutdown --help".


Glxgears No Vertical Synchronization

Glxgears is a very simple benchmarking tool for your graphics card.

Running glxgears with no vsync (vertical synchronization) is a great simple way to do a very simple benchmark of your graphical situation when you are testing out drivers on your linux system.

You just run the command: vblank_mode=0 glxgears

Easy way to see current graphics driver in use in Xorg: egrep -i " connected|card detect|primary dev|Setting driver" /var/log/Xorg.0.log