How to list all environment variables in a c/c++ app

Question

I know that when programming in c++ I can access individual environment variables with getenv.

I also know that, in the os x terminal, I can list ALL of the current

Answer 1

Use the environ global variable. It is a null-terminated pointer to an array of strings in the format name=value. Here's a miniature clone of env:

#include 
#include 

extern char **environ;

int main(int argc, char **argv) {
    for(char **current = environ; *current; current++) {
        puts(*current);
    }
    return EXIT_SUCCESS;
}