DetectOS.cmake

################################################################################
#
# \file      DetectOS.cmake
# \copyright 2012-2015 J. Bakosi,
#            2016-2018 Los Alamos National Security, LLC.,
#            2019-2021 Triad National Security, LLC.
#            All rights reserved. See the LICENSE file for details.
# \brief     Detect operating system
#
################################################################################

function(detect_os)

  if(APPLE)
    set(os "mac")
  elseif(WIN32)
    set(os "windows")
  elseif(EXISTS "/etc/os-release")
    execute_process(COMMAND cat /etc/os-release
                    COMMAND grep ^ID=
                    COMMAND awk -F= "{ print $2 }"
                    COMMAND tr "\n" " "
                    COMMAND sed "s/ //"
                    OUTPUT_VARIABLE os)
  elseif(EXISTS "/etc/issue")
    execute_process(COMMAND cat /etc/issue
                    COMMAND head -n 1
                    COMMAND tr -d '\n'
                    OUTPUT_VARIABLE os)

  endif()

  set(HOST_OS ${os} CACHE STRING
      "Name of the operating system (or Linux distribution)." FORCE)

  mark_as_advanced(HOST_OS)

endfunction()