I have made a program based on some of macro definitions (#define name numeric-value). Now I want to make these changeable from the executable file without rewriting the entire program. How should I do?

You won't be able to change the #defines without recompiling; however, there are a few other possibilities that come to mind...
1. have the program read/write to a config. file (like a .ini file)
2. have the program read/write registry key values.
3. pass arguments to the program with each execution.

maybe others will post with more ideas.

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