4.3BSD - /usr/include/grp.h

   1: /*	grp.h	4.1	83/05/03	*/
   2: 
   3: struct  group { /* see getgrent(3) */
   4:     char    *gr_name;
   5:     char    *gr_passwd;
   6:     int gr_gid;
   7:     char    **gr_mem;
   8: };
   9: 
  10: struct group *getgrent(), *getgrgid(), *getgrnam();

Defined struct's

Usage of this include