hello-elektra.md

Hello, Elektra

This basic tutorial shows you how to compile and run a very basic Elektra application. For this tutorial we assume that you installed Elektra and CMake on your machine. We also assume that you work a Unix based OS like Linux or macOS.

1. Create a folder called Hello somewhere on your disk

2. Copy the file examples/helloElektra.c to the folder Hello you just created

3. Save a file with the following content

   cmake_minimum_required(VERSION 3.0)
   
   find_package(Elektra REQUIRED)
   
   if (ELEKTRA_FOUND)
       message (STATUS "Elektra ${ELEKTRA_VERSION} found")
       include_directories (${ELEKTRA_INCLUDE_DIR})
   
       add_executable (hello helloElektra.c)
       target_link_libraries (hello ${ELEKTRA_LIBRARIES})
   else (ELEKTRA_FOUND)
       message (FATAL_ERROR "Elektra not found")
   endif (ELEKTRA_FOUND)

   as CMakeLists.txt in the folder Hello.

4. Open a shell and change into the directory Hello

5. Create a build directory inside Hello, change into the build directory, and run Cmake:

   mkdir build
   cd build
   cmake ..

   . If everything worked until now, then CMake should print messages that look something like this:

   -- The C compiler identification is AppleClang 8.1.0.8020042
   -- The CXX compiler identification is AppleClang 8.1.0.8020042
   -- Check for working C compiler: usr/bin/cc
   -- Check for working C compiler: usr/bin/cc -- works
   -- Detecting C compiler ABI info
   -- Detecting C compiler ABI info - done
   -- Detecting C compile features
   -- Detecting C compile features - done
   -- Check for working CXX compiler: usr/bin/c++
   -- Check for working CXX compiler: usr/bin/c++ -- works
   -- Detecting CXX compiler ABI info
   -- Detecting CXX compiler ABI info - done
   -- Detecting CXX compile features
   -- Detecting CXX compile features - done
   -- Elektra 0.9.5 found
   -- Configuring done
   -- Generating done
   -- Build files have been written to: Hello/build
   

6. Now it’s time to build your application. For that step run make inside the folder Hello/build:

   make

   . If the last step completed successfully, then the build directory now contains the application hello.

7. You can now run your Elektra application by calling ./hello inside the build directory. The output of the application should look something like this:

   Open key database
   Retrieve key set
   Number of key-value pairs: 0
   Add key user:/test/hello
   Number of key-value pairs: 1
   
   hello, elektra
   
   Delete key-value pairs inside memory
   Close key database
   

8. You can now change the content of helloElektra.c. If you want to compile and execute the updated code, then repeat steps 6 and 7.