Convert an associative array of strings to an array of pointers to
char with a terminating null character (C strings). The resulting
array has a null pointer at the end. This is the format expected by
the execv*() family of POSIX functions for environment variables.
Convert an associative array of strings to an array of pointers to char with a terminating null character (C strings). The resulting array has a null pointer at the end. This is the format expected by the execv*() family of POSIX functions for environment variables.