Allow me:
https://cmake.org/cmake/help/latest/guide/tutorial/A%20Basic%20Starting%20Point.html
current directory: /home/jian/helloc/cmake_begin/step1
then
cd …/step1
then it will return the same directory.
Current CMakeLists.txt
cmake_minimum_required(VERSION 3.10)
project(tutorial)
add_executable(tutorial101 tutorial.c)
cmake ../step1
cmake --build .
then It will generate a executable file then I do
./tutorial101
will print out hello world.