int load_env_file(FILE *f, const char *fname, const char *separator, char ***l);
int load_env_file_pairs(FILE *f, const char *fname, const char *separator, char ***l);
int write_env_file(const char *fname, char **l);
int load_env_file(FILE *f, const char *fname, const char *separator, char ***l);
int load_env_file_pairs(FILE *f, const char *fname, const char *separator, char ***l);
int write_env_file(const char *fname, char **l);