shadow/libmisc/getgr_nam_gid.c

/*
 * Copyright (c) 1991 - 1994, Julianne Frances Haugh
 * Copyright (c) 1996 - 2000, Marek Michałkiewicz
 * Copyright (c) 2000 - 2006, Tomasz Kłoczko
 * Copyright (c) 2007 - 2009, Nicolas François
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the copyright holders or contributors may not be used to
 *    endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <config.h>

#ident "$Id$"

#include <stdlib.h>
#include <errno.h>
#include <grp.h>
#include "prototypes.h"

/*
 * getgr_nam_gid - Return a pointer to the group specified by a string.
 * The string may be a valid GID or a valid groupname.
 * If the group does not exist on the system, NULL is returned.
 */
extern /*@null@*/struct group *getgr_nam_gid (/*@null@*/const char *grname)
{
	long long int gid;
	char *endptr;

	if (NULL == grname) {
		return NULL;
	}

	errno = 0;
	gid = strtoll (grname, &endptr, 10);
	if (   ('\0' != *grname)
	    && ('\0' == *endptr)
	    && (ERANGE != errno)
	    && (/*@+longintegral@*/gid == (gid_t)gid)/*@=longintegral@*/) {
		return xgetgrgid ((gid_t) gid);
	}
	return xgetgrnam (grname);
}