Don't overwrite conf files on install

.gitignore

@@ -14,3 +14,4 @@ lexer.c
 lexer.h
 parser.c
 parser.h
+install_manifest.txt

CMakeLists.txt

@@ -64,9 +64,7 @@ set(CMAKE_C_FLAGS_RELEASE "-O2")
 add_subdirectory(src)
 
 # Install conf files
-FILE(GLOB CONF_FILES "conf/*")
-install(
-	FILES
-	${CONF_FILES}
-	DESTINATION "/etc/zmap/"
-	)
+FILE(GLOB CONF_FILES RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}/conf" "conf/*")
+message(STATUS "${CONF_FILES}")
+configure_file(zmap_conf_install.cmake.in zmap_conf_install.cmake)
+install(SCRIPT zmap_conf_install.cmake)

zmap_conf_install.cmake.in

@@ -0,0 +1,6 @@
+foreach(conf_file ${CONF_FILES})
+	message(STATUS "${conf_file}")
+	if(NOT EXISTS "/etc/zmap/${conf_file}")
+		file(INSTALL "conf/${conf_file}" DESTINATION "/etc/zmap")
+	endif()
+endforeach()