Add CMake install target

[harens]

I understand that make install is not in the build instructions, and that install is not a required target, but I think it is a useful one to have. For instance:

• A user might want to install CipheyCore to a local space
• It makes it easier to write scripts for many package managers
• Also easier to use the library after building from source
• Running make install currently results in the error make: *** No rule to make target 'install'. Stop.

The issue for me was that the DESTDIR variable is used as part of MacPorts to provide a staged install process via make install DESTDIR=/tmp/example. It would be helpful if an install target could be added, although I'd also be grateful for any alternative methods.

Thanks for your help.

To reproduce error

macOS 10.15.6 19G73

xcode-select version 2373

git clone https://github.com/Ciphey/CipheyCore
cd CipheyCore
mkdir build
cd build
cmake .. -DCMAKE_BUILD_TYPE=Release -DCIPHEY_CORE_TEST=OFF
cmake --build . -t ciphey_core
make install

Output

cmake .. -DCMAKE_BUILD_TYPE=Release -DCIPHEY_CORE_TEST=OFF

-- The C compiler identification is AppleClang 11.0.3.11030032
-- The CXX compiler identification is AppleClang 11.0.3.11030032
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /Library/Developer/CommandLineTools/usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /Library/Developer/CommandLineTools/usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found Boost: /usr/local/lib/cmake/Boost-1.74.0/BoostConfig.cmake (found version "1.74.0")  
-- Found Python3: /opt/local/Library/Frameworks/Python.framework/Versions/3.9/include/python3.9 (found version "3.9.0") found components: Development Development.Module Development.Embed 
-- Found SWIG: /opt/local/bin/swig (found version "4.0.2")  
CMake Warning (dev) at /opt/local/share/cmake-3.18/Modules/UseSWIG.cmake:634 (message):
  Policy CMP0078 is not set: UseSWIG generates standard target names.  Run
  "cmake --help-policy CMP0078" for policy details.  Use the cmake_policy
  command to set the policy and suppress this warning.

Call Stack (most recent call first):
  CMakeLists.txt:55 (swig_add_library)
This warning is for project developers.  Use -Wno-dev to suppress it.

CMake Warning (dev) at /opt/local/share/cmake-3.18/Modules/UseSWIG.cmake:486 (message):
  Policy CMP0086 is not set: UseSWIG honors SWIG_MODULE_NAME via -module
  flag.  Run "cmake --help-policy CMP0086" for policy details.  Use the
  cmake_policy command to set the policy and suppress this warning.

Call Stack (most recent call first):
  /opt/local/share/cmake-3.18/Modules/UseSWIG.cmake:736 (SWIG_ADD_SOURCE_TO_MODULE)
  CMakeLists.txt:55 (swig_add_library)
This warning is for project developers.  Use -Wno-dev to suppress it.

-- Configuring done
-- Generating done
-- Build files have been written to: /Users/username/CipheyCore/build

cmake --build . -t ciphey_core

Scanning dependencies of target ciphey_core
[ 14%] Building CXX object CMakeFiles/ciphey_core.dir/src/ausearch.cpp.o
[ 28%] Building CXX object CMakeFiles/ciphey_core.dir/src/ciphers/caesar.cpp.o
[ 42%] Building CXX object CMakeFiles/ciphey_core.dir/src/ciphers/vigenere.cpp.o
[ 57%] Building CXX object CMakeFiles/ciphey_core.dir/src/ciphers/xor_single.cpp.o
[ 71%] Building CXX object CMakeFiles/ciphey_core.dir/src/ciphers/xorcrypt.cpp.o
[ 85%] Building CXX object CMakeFiles/ciphey_core.dir/src/freq.cpp.o
[100%] Linking CXX static library libciphey_core.a
[100%] Built target ciphey_core

make install (ERROR)

make: *** No rule to make target `install'.  Stop.