uclibc-ng/libc/pwd_grp/getgrnam.c

/*
 * getgrnam.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 <errno.h>
#include <fcntl.h>
#include <paths.h>
#include "config.h"

#ifdef __UCLIBC_HAS_THREADS__
#include <pthread.h>
extern pthread_mutex_t __getgrent_lock;
# define LOCK   pthread_mutex_lock(&__getgrent_lock)
# define UNLOCK pthread_mutex_unlock(&__getgrent_lock);
#else
# define LOCK
# define UNLOCK
#endif
static char *line_buff = NULL;
static char **members = NULL;


struct group *getgrnam(const char *name)
{
	int grp_fd;
	struct group *group;

	if (name == NULL) {
		__set_errno(EINVAL);
		return NULL;
	}

	if ((grp_fd = open(_PATH_GROUP, O_RDONLY)) < 0)
		return NULL;

	LOCK;
	while ((group = __getgrent(grp_fd, line_buff, members)) != NULL)
		if (!strcmp(group->gr_name, name)) {
			close(grp_fd);
			UNLOCK;
			return group;
		}

	close(grp_fd);
	UNLOCK;
	return NULL;
}