Two days ago the official hard-float Oracle Java 7 JDK has been announced on the official Raspberry Pi blog. Prior to this there was only the OpenJDK implementation which was lacking performance.
Furterhmore the Raspberry Pi Foundation announced that future Raspbian images would ship with. Oracle Java by default.
If you want to give it a spin you can install the JDK with:
$ sudo apt-get update && sudo apt-get install oracle-java7-jdk
If you work a lot on the command line you are probably familiar with the top utility to see what process is taking the most CPU or memory. There’s a similar utility called htop, which is an advanced, interactive system-monitor utility that can be used as a replacement tool for the default process monitoring command ‘top’ on a Linux ecosystem. This interactive process viewer provides a real-time, dynamic view of what’s happening on your Raspberry Pi system.
If you are overclocking your Raspberry Pi or you just curious how hot this little guy gets, there are two ways to get the internal temperature. Assuming you are running Raspbian as your operating system.
Method 1:
$ /opt/vc/bin/vcgencmd measure_temp This gives you the temperate in in degrees Celsius: temp=54.1'C
Method 2:
If you need the temperature to be more precise (e.g. storing it in an database or for further processing) use the following command:
If you log into your Raspberry Pi using ssh it will prompt you for a password. Having to do this multiple times a days this is very annoying. To ease the pain, and enhance security, you can use public key authentication instead. Therefor you create a pair of keys on your client, and store the public key on your Raspberry Pi. Then you set up an authentication by key. Afterwards the user can login into the Raspberry Pi using his private key.
