How to copy contents of a directory into build directory after make with CMake?

Question

I've got some config files (xml, ini, ...) in the config directory next to the source files. How can I copy all the files in the config directory into the build directory (next to the executable file) each time I make the project?

Answer 1

You can use add_custom_command.

Say your target is called MyTarget, then you can do this:

add_custom_command(TARGET MyTarget PRE_BUILD
                   COMMAND ${CMAKE_COMMAND} -E copy_directory
                       ${CMAKE_SOURCE_DIR}/config/ $<TARGET_FILE_DIR:MyTarget>)

This executes every time you build MyTarget and copies the contents of "/config" into the directory where the target exe/lib will end up.

As Mark Lakata points out in a comment below, replacing PRE_BUILD with POST_BUILD in the add_custom_command ensures that copying will only happen if the build succeeds.

Explanation

• ${CMAKE_COMMAND} is the path to CMake
• -E makes CMake run commands instead of building
• copy_directory is a Command-Line Tool
• config is the directory (that falls under the root of the project) who's contents will be copied into the build target
• $<TARGET_FILE_DIR:MyTarget> is a generator expression, described in the add_custom_command documentation.