DmitriiPIt is showed in a simple example:
installCommand
https://www.sidefx.com/docs/hdk/expr_2command_8_c-example.html#a10 [www.sidefx.com]
amin khormaei
it's not good for beginners
It is easy if you read it from beginning and it would be hard if you suddenly jump at the middle of HDK.
This is not Houdini documentation responsibility to teach you how CMake works or how C++ compilers work.
There are many samples in HDK with comments which show you how to use development kit.
You should learn C++ deeply enough to work with HDK otherwise it would be really annoying to work with.
You can also use Inlinecpp module in Python:
https://www.sidefx.com/docs/houdini/hom/extendingwithcpp.html [www.sidefx.com]