How to define a constant using Clang that can be used in C source files?

Asked Oct 27 '19 at 17:59

Active Oct 27 '19 at 17:59

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How can I define a constant (e.g. #define) on the command-line using clang that can be accessed in the compiled C source files?

I've seen C source code like the following, where LEVELNAME is defined nowhere in the sources, so it has to be specified at compile-time somehow:

#include <err.h>
#include <stdio.h>
#include <unistd.h>

#define BANNER \
  "Welcome to " LEVELNAME ", brought to you by https://example.com"

asked Oct 27 '19 at 17:59

Shuzheng

`-DBANNER="some level name"` though you'll also want to stringify the definition like `#LEVELNAME` – kmdreko Oct 27 '19 at 18:05
Is it possible to set `LEVELNAME` to e.g. `folder/filename`? Do you know how? @kmdreko – Shuzheng Oct 27 '19 at 18:14

0 Answers0