#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
int getgrouplist(const char *, gid_t, gid_t *, int *);
int setgroups(size_t, const gid_t *);
#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
int getgrouplist(const char *, gid_t, gid_t *, int *);
int setgroups(size_t, const gid_t *);