当程序需要以 sudo 运行时，读取 ~/.config 下的程序配置文件

Question

I'm building a program in C that reads it's configurations from the user's config directory and it gets the ~ path using getenv("HOME") . Since this program needs root privileges if I run it as a sudo the getenv("HOME") changes and I can't read the configurations file under ~/.config .
Right now I have 2 ideas in my mind how can I do that:

1. To change the ownership of the program to root, then give it suid permission for user, which I think is not very recommended since it can cause vulnerabilities.
2. To run program with sudo , get the name if the logged user using getlogin() then I can make the ~ path by gluing /home/getlogin() return address/ . Bu the truth I'm a little bit afraid of this solution and I don't know how relevant it is.

So I'm here guys to ask for some ideas if that possible.
Thanks for you time.

Update:
Maybe it is good to note that the specific part which requires the root privileges is the part of the code which executes program that requires these privileges from /usr/bin using a function that forks from parent process then execute the program using execv() .

Answer 1

So for everyone who will face the same problem I managed to get an solution for executing program from /usr/bin/ without technically prepending sudo at the beginning of the program which will change the getenv("HOME") path.
So lets say I have this function that forks and run a program:

/*
*This function will fork the parent process to create a
*child process then execute commands using one of the exec
*familie's functions. Return -1 for fork failure, 1 for execv() 
*failure, otherwise 0.
*/
int exec_command(const char *prog_name, char *commands[]) {
    char prog_path[strlen("/usr/bin/")+strlen(prog_name)];
    int status;
    pid_t pid;
    pid_t ret;

    sprintf(prog_path, "/usr/bin/%s", prog_name);
    pid = fork(); //Create a new child process
    if(pid == -1) {//If failed to create new child
        fprintf(stderr, "An error occured while creating a child process.\n");
        return -1;
    }
    else if(pid != 0) { //If child process didnt start
        while((ret = waitpid(pid, &status, 0)) == -1) { //Wait for child
            if(errno != EINTR) { //If the waitpid() error isnt an interrupte signal
                fprintf(stderr, "An error occured while waiting for the child process.\n");
                return -1;
            }
        }
    }
    else 
        if(execv(prog_path, commands)==-1) //If command wasnt found
            return 1;
    return 0; 
}

And for example I want to install a package using pacman (which obviously requires root privileges), I can do something like this:

int main() {
   char *command[] = {   
      "sudo", "pacman", //Sudo is the program name, pacman is the program i want to execute using sudo.    
      "-S", "package_name", NULL   
   };

   exec_command(command[0], command);   
   return 0;
}

This way I manged to execute program that requires root privileges without prepending sudo when executing my program which gives me the chance to get user's home path before calling the exec_command() because sudo won't be executed before this point.