This is an example C++ project which uses the gflags library for the parsing of the command-line flags. It demonstrates the use of either Bazel or CMake for the build of the project where the source code of the gflags library is optionally directly included in the example project's source tree using the Git submodule command. When the submodule is not initialized, an external installation of the gflags library is required instead.
Use the git clone command to download this gflags example project:
git clone --depth=1 https://github.com/gflags/example.git gflags-example
cd gflags-example
When gflags should be build as subproject of the example which does not require an external installation of the gflags library, run the following command in the top-level directory of the local Git repository after the clone command. This is only recommended when CMake is used for the build configuration and no separate gflags installation is available.
git submodule update --init
Create a build directory inside the example project directory and configure the build using CMake to generate the Makefiles for GNU Make:
mkdir build && cd build
cmake -D CMAKE_BUILD_TYPE=Release ..
Then build the example executable named "foo" using GNU Make:
make foo
The resulting binary is bin/foo inside the build directory.
The Bazel build tool uses the information in the WORKSPACE file to download and build the gflags library prior to the example binary. To build the example executable target named "foo", run the following command in the top level directory of the gflags example project which contains the WORKSPACE file. This will clone the gflags project and build the gflags library prior to the example executable upon first invocation. Bazel is caching the build files of the external gflags dependency and will not rebuild gflags when the foo/foo.cc file changes.
bazel build foo
The resulting binary is bazel-bin/foo/foo inside the workspace directory.