cmake HAVE_FLOCK examples

DCMTK/dcmtk CMake/GenerateDCMTKConfigure.cmake :521 

CHECK_FUNCTION_EXISTS(flock HAVE_FLOCK)

Sneeds-Feed-and-Seed/sneedacity CMakeLists.txt :410 

check_symbol_exists( flock "sys/file.h" HAVE_FLOCK )