Specifying include directories on the cmake command line

Question

Is it possible to specify an include directory when running `cmake`. For example ``` cmake . -INCLUDE=/foo/bar ``` The header files are in a separate directory from the sources that I would like to compile, and I would like to remedy this without tinkering with the `Makefile` generated by `cmake`. Update The project does have a `CMakeLists.txt`. Excerpt: ``` INCLUDE_DIRECTORIES(${EO_SOURCE_DIR}/src) INCLUDE_DIRECTORIES(${EO_SOURCE_DIR}/src/ga) INCLUDE_DIRECTORIES(${EO_SOURCE_DIR}/src/utils) ``` Can `${EO_SOURCE_DIR}` be set from the command line?

Accepted Answer

If the path to your headers is fixed in relation to your sources, then you should be able to avoid having to pass this info via the command line.

Say your project's directory structure is:

```
/CMakeLists.txt
/my_sources/main.cpp
/my_sources/foo.cpp
/my_includes/foo.hpp
```

and in your CMakeLists.txt, you currently have something like:

```
add_executable(MyExe my_sources/main.cpp my_sources/foo.cpp)
```

then to add the `/my_includes` folder to the the list of include search paths, you only need to add the following:

```
include_directories(my_includes)
```

For further info about `include_directories`, run

```
cmake --help-command include_directories
```

Answer to update in question:

Yes, using the `-D` command line option just do

```
cmake . -DEO_SOURCE_DIR:PATH=<Path to required dir>
```

The variable `${EO_SOURCE_DIR}` gets cached as a result of this, so you only need this `-D` argument once (unless the required path changes or you delete your CMakeCache file, etc.)

Specifying include directories on the cmake command line

Solution

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