Category Archives: Setup

Import and export SQL tables

You should not use phpmyadmin to export big tables from mysql. You may get partial exports because of php server timeouts.

Best way is to connect via SSH to the server and use mysqldump to export the dataset. Then you can download it and transfer it to the new server. There you could use the mysql command to import the dataset.

Continue reading Import and export SQL tables

qdpm/softaculous – Internal Server Error

Whoaaa, that was a nasty bug 😮

Use: Debian 8.8 & Apache 2.4 & php 7.0:

  1. Install qdpm via softaculous (or manually, it doesn’t matter)
  2. Navigate to admin page.

and … BOOM: Internal Server Error.

Messages totally misleading. Directory permissions are okay as is the default .htaccess file. Bug is much deeper.

Continue reading qdpm/softaculous – Internal Server Error

Upgrade to gcc 6.3+ in Ubuntu

To upgrade gcc to gcc6 use the following commands:

sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get install gcc-6 -y


To set the new gcc as default use the following:

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-6 60 --slave /usr/bin/g++ g++ /usr/bin/g++-5

Once you have executed the previous command, g++ may not be available.

So you can execute the following to create a link:

sudo ln -s /usr/bin/g++-5 /usr/bin/g++


Simple SSL configuration for Apache-Tomcat

For the official instructions (Tomcat 8), read this page

The following instructions are for development servers only:

Step 1: Create a keystore file to store the server’s private key and self-signed certificate:

For Windows:

"%JAVA_HOME%\bin\keytool" -genkey -alias tomcat -keyalg RSA

For Unix/Linux:

$JAVA_HOME/bin/keytool -genkey -alias tomcat -keyalg RSA

You will be asked for various information. Remember the password you typed at this step.

At the end of the procedure, keytool will create a file named “.keystore” to your home directory. By default it is hidden. This file should be moved to Apache-Tomcat home directory and can be renamed (eg to “keystore”).

Step 2: Disable APR:

Edit server.xml and comment out the following line:


Step 3: Activate the SSL connector

Edit server.xml and add (or uncomment and modify) the following lines:

    sslProtocol="TLS" />

You will have you replace “12345678” with your password.

You will also have to replace “keystore” with the full path to the keystore file generated at Step 1.

Step 4: Restart Tomcat

Do not forget to restart Apache-Tomcat



Netbeans C/C++ template with Valgrind and -Wall

Netbeans is a great free IDE, one I recommend to all beginners.

For C/C++ coding, it has one important drawback though: -Wall is not selected by default, which is something absolutely required for beginners.

For this reason, I have created my own template (-wall, run at external terminal, valgrind configuration etc) which is available here

In the following page you can find how to create and use one of your own:

Basically you point the IDE to an existing NetBeans project and tell it to use that as a template. You use a module project as a wrapper: This will allow you to turn the template project into an NBM file (“NetBeans Module”) that can be installed into the IDE like a plugin. After installing the custom plugin, the template project will appear in the “New Project” wizard. This is how you do it:

  1. Take a NetBeans project that you want to be the template project, and open it in the IDE. Let’s call it FooApp.
  2. Create an empty NetBeans Module project. Name it something recognizable (such as FooAppTemplate or whatever).
  3. In the Projects window, right-click the empty module project. Create a new file by choosing New > Other > Module Development > Project Template from the context menu.
  4. Use the Template Wizard to configure the template. Point it to the template project FooApp and choose a category (Java SE, Java EE, Java ME, Ruby, etc).
  5. Here comes the important part – you save the template as an NBM file. Right-click the module project in the Projects window, and select Create NBM. Look into the Output window to see where the file was saved (for instance FooAppTemplate/build/myorg-fooapptemplate.nbm).
  6. To install the template into the IDE, go to Tools > Plugins > Downloaded. Click Add Plugin, browse to your NBM file and install it. If you give the NBM file to other developers, that’s how they install the template.
  7. (Alternatively, right-click the module project in the Project window and select “Install in Development IDE”. This is another way to install it for somebody who has the module project still open.)

Install latest Qt to Ubuntu

  1. sudo mkdir opt/Qt         (notice Q has to be uppercase)
  2. Download open source Qt run file from official site
  3. execute .run file
  4. install at opt/Qt

Have more than 1 versions of qt?

sudo update-alternatives –install /usr/bin/qmake qmake /opt/Qt/ 10

Repeat for each version but with a different number.

To select which version to use as default, run:

sudo update-alternatives –config qmake