Ingress: Level 16 reached…

After long time playing google/niantic's ingress (the predecessor of pokemon go - all the arenas are portals in ingress, most of them created by ingress players) i reached the last level:

And the usual welcome package:

I am wondering, wether i should continue playing or quit the game for now or ever.
Perhaps reading this discussion (What do lvl 16 players play for?) may help me.

(bash): The most useless commands (8)

After talking about

  1. rev
  2. yes
  3. sl
  4. cowsay
  5. cmatrix
  6. cal
 i found another funny command:
Its manpage tells the following:
       Rig  is a utility that will piece together a random first name, last name, street num‐
       ber and address, along with a geographically consistant (ie, they all match  the  same
       area) city, state, ZIP code, and area code.

       It is suitable for such applications as feeding the NY times registration (more...)

OpenJDK 9: Jshell – Using Swing / doing GUI stuff

After the buitin commands of jshell and how to load and save scripts i tried to get swing components running.

I created a script
import javax.swing.*;       

JFrame frame = new JFrame("HelloWorldSwing");
JLabel label = new JLabel("Hello World");
But this does not work with Ubuntu:
# A fatal error has been detected by the Java Runtime Environment:

Bash: enabling Eclipse for Bash Programming | Plugin basheclipse (debugging) part 1

In my last posting i showed how to install the plugin shelled and its configuration options.

Now the next step is to install basheclipse, which enables eclipse in conjunction with shelled to debug bash scripts.

Step 1: Download basheclipse

Step 2: Do not copy the jar file to the plugins directory if you are using Eclipse Neon. Copy them to the dropins directory.

Step 3: Restart eclipse (and wait. I had to wait nearly 5 (more...)

OpenJDK 9: Jshell – how to load scripts and how to save/persist finished snippets

In my last posting i showed the builtin jshell commands and how to start working with the java shell.

What about loading and saving scripts?

I created a file myshell.txt with this content:
class MyClass {
 private int a;
 public MyClass(){a=0;}
 int getA() {return a;};
 void setA(int var) {a=var; return;}
MyClass ZZ;
ZZ = new MyClass();
The help shows the following:
-> /help /open

|  /open

|  Open a (more...)

OpenJDK 9: JShell – an interactive java interpreter shell | builtin commands

One of the new features of java 9 is jshell (JEP 222).

On my ubuntu system the installation was quite easy:
# apt-get install openjdk-9-jdk-headless
and you can find
$ ls /usr/lib/jvm/java-9-openjdk-amd64/bin/
idlj       jcmd    jmap        jstatd       schemagen
jar        jdb     jmod        keytool      serialver
jarsigner  jdeps   jps         orbd         servertool
java       jhsdb   jrunscript  pack200      tnameserv
javac      jimage  jsadebugd   policytool   unpack200
javadoc    jinfo   jshell      rmic         wsgen
javah      jjs     jstack      rmid         wsimport
javap      jlink   jstat       rmiregistry  xjc
 (in the third (more...)

Bash: enabling Eclipse for Bash Programming | Plugin Shelled (shell editor)

After writing several posts about useless shell commands i tried to enable Eclipse for working with the bourne again shell.

First step is to get a plugin for syntax highlighting. The plugin shelled
is very easy to find. Just download the zip

and in Eclipse go to "help --> install new software".
There you have to add the archive:
And all other clicks are straight forward:

After the installation of the plugin you (more...)

(bash): The most useless commands (7)

After talking about
  1. rev
  2. sl
  3. cowsay
  4. cmatrix
here another pretty useless command:
Today with every smartphone having its own calendar app or every e-mail program with integrated time planning function this command is no more needed. The manpage says:
     cal, ncal — displays a calendar and the date of Easter
And here we go:
$ cal 2000

(bash): The most useless commands (6)

After talking about
  1. rev
  2. sl
  3. cowsay
 i found another funny command:
The manpage says:
       CMatrix - simulates the display from "The Matrix"
and it is true:

(bash): The most useless commands (5)

In a comment Albert Godfrind pointed out, that the commands i was talking about like
  1. rev
  2. sl
  3. cowsay
are not really bash commands (in a way that they will be installed within the installation of the bash shell). They are commands, which can be used from on every shell. So my headline is a little bit missleading - thanks for this notice.

Just for clarification here a list with all bash builtin commands:

Bash: The most useless command (4)

The blog statistics show, that there are many people reading the posts about useless commands. And there is the next candidate:
Now you are thinking, what is cowsay?
       Cowsay  generates  an  ASCII picture of a cow saying something provided by the user.  If run with no arguments, it accepts standard input, word-wraps
       the message given at about 40 columns, and prints the cow saying the given message (more...)

Bash: The most useless command (3)

The blog statistics show, that there are many people reading the posts about useless commands. And there is the next candidate, suggested by an anonymous comment:
This is my most hated program on a shell. Why?
sl − display animations aimed to correct users who accidentally enter sl instead of ls.
and this program is not interruptable by ctrl-c.
It shows a train running from the left to the right
and blocks (more...)

Ubuntu: mouse jumps to trash icon / move to lower left corner / bottom left

There are many questions about jumping mouse cursors on ubuntu.
And there are often answers like
  • clean your touchpad
  • your touchpad is broken
  • send your laptop back
But there are so many people suffering this, so it is not reasonable that all these touchpads do not work well.

One thing to solve this is to install
but this does not really help.
Next thing:
add-apt-repository ppa:atareao/atareao
apt-get update
apt-get install touchpad-indicator

Bash: The most useless command (2)

The last posting about useless commands for bash discussed the command
. One nice comment pointed out, that the rev command can be used for searching inside logfiles (Thanks to

Like it was said there, the command
looks even more useless:
       yes - output a string repeatedly until killed
       yes [STRING]...
Ok - it can be used for scripts to answer call backs. But (more...)

Bash: The most useless command

After many years working with the bourne again shell i still learn some commands, which i never used.
I am completely convinced that i discovered the most useless command:
The manpage says:
rev - reverse lines characterwise
 Is there anything, where i can use this command?

Ok. I can check if a word is a palindrome (like 123321 or otto):

# Shell script to test if a string is a palindrome
# (more...)

Ubuntu: Eclipse does not find openjdk (JRE)

On my Ubunut linux i decided to do some Java programming.
So first step is to install java:
apt-get install openjdk-9-jdk openjdk-9-demo openjdk-9-doc openjdk-9-jre-headless openjdk-9-source
This just works like expected. But after that i installed eclipse.
Download via was easy and the installation ran without any error.
But Eclipse was not able to find the JRE for compiling, autocorrection, etc.

For all developers, which are not used to linux:
The JRE is (more...)

Ubuntu: visudo problem / NOPASSWD option does not work for commands

It is always the same:
After installing a new Linux commands like
only work with entering your password everytime (or precisely: after every reboot).
This can be changed with visudo:
export EDITOR=vi; visudo
 Inside the /etc/sudoers.conf you will see:
# User privilege specification
root    ALL=(ALL:ALL) ALL

# Members of the admin group may gain root privileges
%admin ALL=(ALL) ALL
And this is the problem:
First idea is to double the line
root    (more...)

UEFI and Linux: Installation of Ubuntu on a new laptop / How to add grob on UEFI

On my new laptop i decided to install in addition to windows 10 a linux distribution.
First idea was to install debian linux but the debian installer does not provide any functionality to resize the partitions. And without this, the windows partition will be erased after the installtion.
I knew, that the ubuntu installer had this functionality, so i created a usb stick and tried installing ubuntu.

The installation went through like a charm, but (more...)

review at amazon: Apache SOLR for newbies

Last weekend this book fell into my hands:

Paul Lawson wrote a splendid introduction into Apache SOLR. At the beginning he describes the motivation behind the project SOLR:
 "Outside the firewall  [searching] is used to make money, and inside to save money."
Within 130 pages this books covers everything from installation, adminstration GUI, examples to start (importing documents, first searches, etc.) and the quick overview to the fundamental configuration files.
If you are (more...)

Touchpad tuning on linux: touchpad-indicator…

I encoutered some problems with my touchpad on ubuntu:
While typing some text, the touchpad signalled the mouse some strange moves. Sometimes it marked parts of the text and the next key erased the highlighted text...

First idea was to edit the xorg.conf or something else, but i found a less difficult was via touchpad-indicator.

It can be installed via
apt-get install touchpad-indicator
Alittle problem is, that you can not run it via cli (more...)