how to define a string in gcc command line?

Question

In gcc command line, I want define a string for source code. line -Dname=Mary. then in the source code I want printf("%s", name); to print Mary. How could I do it?

Thanks

Answer 1

Two options. First, escape the quotation marks so the shell doesn't eat them:

gcc -Dname=\"Mary\"

Or, if you really want -Dname=Mary, you can stringize it, though it's a bit hacky.

#include <stdio.h>

#define STRINGIZE(x) #x
#define STRINGIZE_VALUE_OF(x) STRINGIZE(x)


int main(int argc, char *argv[])
{
    printf("%s", STRINGIZE_VALUE_OF(name));
}

Note that STRINGIZE_VALUE_OF will happily evaluate down to the final definition of a macro.