Make sure fmt is installed.

$ git clone [email protected]:szaszm/sd-journal-util.git
$ cd sd-journal-util/
$ mkdir build
$ cd build
$ cmake ..
$ cmake --build .
$ bin/sd_journal_cat

This is under the Unlicense, which is basically a do-whatever-you-want license. The code was an early experimentation that led to the implementation of the ConsumeJournald processor in MiNiFi C++. If you want to reuse parts of that work, you can also choose to do so under the Unlicense as long as you can verify that the copyright of all of the parts you're using is mine. This is the case for the whole file at the time of writing this.