/* * initgroups.c - This file is part of the libc-8086/grp package for ELKS, * Copyright (C) 1995, 1996 Nat Friedman <ndf@linux.mit.edu>. *  *  This library is free software; you can redistribute it and/or *  modify it under the terms of the GNU Library General Public *  License as published by the Free Software Foundation; either *  version 2 of the License, or (at your option) any later version. * *  This library is distributed in the hope that it will be useful, *  but WITHOUT ANY WARRANTY; without even the implied warranty of *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU *  Library General Public License for more details. * *  You should have received a copy of the GNU Library General Public *  License along with this library; if not, write to the Free *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */#include <unistd.h>#include <string.h>#include <fcntl.h>#include "grp.h"#include "config.h"int initgroups(__const char *user, gid_t gid){	register struct group *group;#ifndef GR_DYNAMIC_GROUP_LIST	gid_t group_list[GR_MAX_GROUPS];#else	gid_t *group_list = NULL;#endif	register char **tmp_mem;	int num_groups;	int grp_fd;	if ((grp_fd = open("/etc/group", O_RDONLY)) < 0)		return -1;	num_groups = 0;#ifdef GR_DYNAMIC_GROUP_LIST	group_list = (gid_t *) realloc(group_list, 1);#endif	group_list[num_groups] = gid;#ifndef GR_DYNAMIC_GROUP_LIST	while (num_groups < GR_MAX_GROUPS &&		   (group = __getgrent(grp_fd)) != NULL)#else	while ((group = __getgrent(grp_fd)) != NULL)#endif	{		if (group->gr_gid != gid)		{			tmp_mem = group->gr_mem;			while (*tmp_mem != NULL) {				if (!strcmp(*tmp_mem, user)) {					num_groups++;#ifdef GR_DYNAMIC_GROUP_LIST					group_list = (gid_t *) realloc(group_list, num_groups *						sizeof(gid_t *));#endif					group_list[num_groups-1] = group->gr_gid;				}				tmp_mem++;			}		}	}	close(grp_fd);	return setgroups(num_groups, group_list);}