example_3

Summary

This example shows a more elaborate configuration for a C++ project yielding an executable

• It relies on one library and uses CMake's FetchContent feature to include it
• It has configuration for releasing packages for all major platforms

Build Instructions and More

Overview

Here we illustrate recommended ways to use cmake. In contrast to the earlier examples we call cmake from the top level and use it in a portable way. For completeness we also show the alternative variants which work on systems that have Gnu make available where you change into the build directory and call all commands from there. It is still recommended to get used to the portable versions. See the CMake command line tool documentation for details.

Preparation

Create a subdirectory build_example_3 and prepare the build system for the source in example_3 in this subdirectory:

cmake -D CMAKE_BUILD_TYPE=Release -B build_example_3 -S example_3
# for debug builds use   
# cmake -D CMAKE_BUILD_TYPE=Debug -B build_example_3 -S example_3

Building the example_3 project:

Call cmake from the top level like this:

cmake --build build_example_3 --config Release --target example_3

Creating release packages

Call cmake from the top level like this:

cmake --build build_example_3 --config Release --target package

Alternative Commands for Creating Releases on Linux

Switch to the directory and omit the previously configured Release flag:

cd build_example_3
make package

On Linux, this yields DEB, RPM, and TGZ packages. Note, that CPack allows you to create the packages separately:

cd build_example_3 
cpack -G "DEB" # this yields the Debian package only

You can inspect the content of the Debian package using

sudo dpkg -c example_3-1.0.0-Linux.deb

The procedure is similar for rpm files:

cpack -G "RPM"
rpm -qlp example_3-1.0.0-Linux.rpm

Installing the Debian Package

sudo dpkg -i example_3-1.0.0-Linux.deb

Uninstalling the Debian package

sudo dpkg -r example_3

Miscellanneous

Check the RUNPATH settings of the executable

cd build_example_3
chrpath -l example_3

Learn about the cmake options in this project by calling

cd build_example_3
cmake -LH -N ../example_3