pollution: gid
struct group *getgrgid(gid_t gid); 

pollution: name
struct group *getgrnam(const char *name); 

pollution: gid
pollution: result_buf
pollution: buffer
pollution: buflen
pollution: result
int getgrgid_r(gid_t gid, struct group *result_buf, char *buffer, size_t buflen, struct group **result); 

pollution: name
pollution: result_buf
pollution: buffer
pollution: buflen
pollution: result
int getgrnam_r(const char *name, struct group *result_buf, char *buffer, size_t buflen, struct group **result); 

pollution: getgrent
struct group *getgrent(void); 

pollution: endgrent
void endgrent(void); 

pollution: setgrent
void setgrent(void); 

pollution: user
pollution: groups
pollution: ngroups
pollution: getgrouplist
int getgrouplist(const char *user, gid_t group, gid_t *groups, int *ngroups); 

pollution: user
pollution: gid
pollution: initgroups
int initgroups(const char *user, gid_t gid); 

pollution: size
pollution: list
pollution: setgroups
int setgroups(size_t size, const gid_t *list);