/* Copyright (C) 1991,1993,1996-1999,2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.
*/


#include <stdio_private.h>
#include <string.h>


/** Generate a unique filename in P_tmpdir.
 *	This function is *not* thread safe!
 */

char *
tmpnam (char *s)
{
	static char tmpnam_buffer[L_tmpnam];

	/* By using two buffers we manage to be thread safe in the case where S != NULL.  */
	char tmpbufmem[L_tmpnam];
	char *tmpbuf = s ?: tmpbufmem;

	/* In the following call we use the buffer pointed to by S if
	 * non-NULL although we don't know the size.  But we limit the size
	 * to L_tmpnam characters in any case.
	 */
	if (__builtin_expect(__path_search(tmpbuf, L_tmpnam, NULL, NULL, 0), 0))
		return NULL;

	if (__builtin_expect(__gen_tempname(tmpbuf, __GT_NOCREATE), 0))
		return NULL;

	if (s == NULL)
		return (char *)memcpy(tmpnam_buffer, tmpbuf, L_tmpnam);

	return s;
}

//link_warning (tmpnam, "the use of `tmpnam' is dangerous, better use `mkstemp'")
