C Macros to create strings

Question

Alternative Titles (to aid search)

• Convert a preprocessor token to a string
• How to make a char string from a C

Answer 1

What you need are the # and ## operators, and automatic string concatenation.

The # preprocessing operator turns the macro parameter into a string. The ## operator pastes two tokens (such as macro parameters) together.

The possibility that comes to mind to me is

#define IV_DOMAIN domain.org
#define IV_SECURE(DOMAIN) "secure." #DOMAIN

which should change IV_SECURE to

#define IV_SECURE "secure." "domain.org"

which will automatically concatenate to "secure.domain.org" (assuming the phases of translation are the same in C as C++).

ANOTHER EDIT: Please, please read the comments, which show how I've managed to get confused. Bear in mind that I am thoroughly experienced in C, although perhaps a touch rusty. I would delete this answer, but I thought I'd leave it as an example of how easy it is to get confused by the C preprocessor.