FIND_PACKAGE(PkgConfig REQUIRED)
pkg_check_modules(SYSTEMD "systemd")

if (SYSTEMD_FOUND AND "${SYSTEMD_SERVICES_INSTALL_DIR}" STREQUAL "")
  execute_process(COMMAND ${PKG_CONFIG_EXECUTABLE}
    --variable=systemdsystemunitdir systemd
    OUTPUT_VARIABLE SYSTEMD_SERVICES_INSTALL_DIR)
  string(REGEX REPLACE "[ \t\n]+" "" SYSTEMD_SERVICES_INSTALL_DIR
    "${SYSTEMD_SERVICES_INSTALL_DIR}")
elseif (NOT SYSTEMD_FOUND AND SYSTEMD_SERVICES_INSTALL_DIR)
  message (FATAL_ERROR "Variable SYSTEMD_SERVICES_INSTALL_DIR is\
  defined, but we can't find systemd using pkg-config")
endif()

if (SYSTEMD_FOUND)
  set(WITH_SYSTEMD "ON")
  message(STATUS "systemd services install dir: ${SYSTEMD_SERVICES_INSTALL_DIR}")
else()
  set(WITH_SYSTEMD "OFF")
endif (SYSTEMD_FOUND)
