Windows Install `oatpp-zlib`

[lganzzzo]

By @AlexandreHURDYK

I think I've successfully managed to compile oatpp-zlib for windows. Here's the procedure :

You will need the following files :

• zlib.h
• zconf.h
• zlib.lib
• oatpp must be compiled and installed on your computer.

Steps :

• Create a folder containing all your zlib components.

• Open a console in administrator mode. This is very important, otherwise you won't be able to compile anything.

• Clone the repo : $ git clone https://github.com/oatpp/oatpp-zlib.git

• Enter the directory : $ cd oatpp-zlib

• Create the build directory : $ mkdir build

• Go inside that directory : $ cd build

• Execute the following command :

  $ cmake .. -DZLIB_INCLUDE_DIR=PATH\TO\zlib\INCLUDES -DZLIB_LIBRARY=PATH\TO\zlib.lib
  

  Mind the -DZLIB_LIBRARY argument ! You need to literally make it point to your zlib.lib file (ex : C:/path/to/zlib/zlib.lib).
  Otherwise, you will get compilation errors.

  Another compilation error I personally encountered is due to a missing "unistd.h" library. The thing is, unistd.h is a Linux library
  and you're not supposed to be able to use it on windows (though some compilers seem to have a built in version of unistd.h for
  windows). If you get compilation errors related to unistd.h, you may have to edit zconf.h :
  --> Find the following three lines (I've personally found them starting from line 434 in the zconf.h file) :

  #if 1 
  #  define Z_HAVE_UNISTD_H
  #endif

  --> Comment them. This should prevent unistd from being used. I recommend saving your precedent version of zconf.h before
  doing something like this.

• FINAL STEP : perform the following command depending which kind of application you want to run :
  --> For a debug application : $ cmake --build . --target INSTALL
  --> For a release application : $ cmake --build . --target INSTALL --config Release

If at this point you get mismatch errors, it means your oatpp installation directory doesn't match the compilation mode of your library : you will need to re-compile oatpp with a compilation mode matching the one you chose for the oatpp-zlib module (debug for debug, release for release).
Small reminder about how to compile oatpp :

$ git clone https://github.com/oatpp/oatpp.git
$ cd oatpp\
$ MD build
$ cd build\

$ cmake ..
//For a debug app :
$ cmake --build . --target INSTALL 
//For a release app :
$ cmake --build . --target INSTALL --config Release