Detect current CMake version using CMake

Question

I am working on a project that uses CMake. The top `CMakeLists.txt` file contains the following line: ``` cmake_minimum_required(VERSION 3.7.2) # Kittens will die if you switch to an earlier version of CMake. We suggest using CMake 3.8.0. ``` I want to force all developers to switch to CMake 3.8.0, but for some reasons, not all developers have administration rights and are not able to switch from 3.7.2 to 3.8.0 immediately. Actually, we do not need any new features of version 3.8.0, but our policy is to use always the newest and greatest tools to prevent "porting up" problems in the future - for instance switching fast from Qt4 to Qt5 was a good decission in the past - I know switching always to the newest libraries and tools has also some drawbacks as discussed here, but we want to do it this way. Because of this, instead of forcing everyone to use version 3.8.0, I'd like to output a warning message if CMake 3.7.2 is used. Somehow like this: ``` # not working - just pseudocode if(CMA…

Accepted Answer

There exist a few variables for that, described here:

`CMAKE_MAJOR_VERSION` major version number for CMake, e.g. the "2" in CMake 2.4.3 `CMAKE_MINOR_VERSION` minor version number for CMake, e.g. the "4" in CMake 2.4.3 `CMAKE_PATCH_VERSION` patch version number for CMake, e.g. the "3" in CMake 2.4.3

Also, the variable `CMAKE_VERSION` contains the string for the version. In your case, you would, for instance, use the following:

```
if(CMAKE_VERSION VERSION_LESS "3.8.0") 
    message("Please consider to switch to CMake 3.8.0")
endif()
```

Other comparison operators are `VERSION_EQUAL` and `VERSION_GREATER`.

Detect current CMake version using CMake

Solution

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