Question

This is driving me nuts. I have a macro defined on the command line with the -D option

-DFOO="foobarbaz"

And then I want to do something like this

string s = "FOO" ;

To get

string s = "foobarbaz" ;

Because apparently the quotes from the command line are stripped away, even when I try to escape them with \. I’ve tried everything I could think with stringification and additional macros and it just won’t work. Either I get an error from the preprocessor about misplaced # signs, or I end up with

string s = foobarbaz ;

which obviously won’t compile.

Answer 1

Use this on the command line:

-DFOO="\"hello world\""

For example test.cpp is:

#include <cstdio>
#include <string>
#include <iostream>

std::string test = FOO;

int main()
{
    std::cout << test << std::endl;
    return 0;
}

Compiling and running gives:

$ g++ -DFOO="\"hello world\"" test.cpp
$ ./a.out 
hello world

EDIT This is how you would do it from a Makefile:

DEFS=-DFOO="\"hello world\""

test: test.cpp
    $(CXX) $(DEFS) -o test test.cpp