Question

Our code has versioning information hardcoded in printf in at least 20 different files like:
printf("Software version v11.2"); This means changing 20 files everytime there is an update.

Instead i wish to use a macro and #include it in a common.h file, such that version update is just changing one macro, that’s all.

I tried something like:

#include <stdio.h>
#define VERSION "v11.2"
int main()
{
  printf("Trying to print macro: ", VERSION);
}

But this style of “string””string” works in Java not in C.
Any ideas how to accomplish it?

We will use the gcc for compilation.

NOTE: The macro is also used in some typical *.rc files, where we can’t use a variable, and somewhere these rc files are parsed using SQL query. So we can’t use variables like char ver[]=”v11.2″

Answer 1

Here are two possible solutions.

#include <stdio.h>
#define VERSION "v11.2"
int main()
{
  // Let printf insert the string when doing the output.
  printf("Trying to print macro: %s\n", VERSION);
  // Let the compiler concatenate the strings.
  puts("Trying to print macro: " VERSION);
  // Let the compiler concatenate the strings, can be assigned to a variable.
  const char buf[] = "Trying to print macro: " VERSION;
  puts(buf);
}