glibc/stdio-common/tmpnam.c

48 lines
1.6 KiB
C

/* Copyright (C) 1991,1993,1996,1997,1998,1999 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <stdio.h>
#include <string.h>
static char tmpnam_buffer[L_tmpnam];
/* Generate a unique filename in P_tmpdir.
This function is *not* thread safe! */
char *
tmpnam (char *s)
{
/* By using two buffers we manage to be thread safe in the case
where S != NULL. */
char tmpbuf[L_tmpnam];
/* 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 (__path_search (s ? : tmpbuf, L_tmpnam, NULL, NULL, 0))
return NULL;
if (__gen_tempname (s ? : tmpbuf, __GT_NOCREATE))
return NULL;
if (s == NULL)
return (char *) memcpy (tmpnam_buffer, tmpbuf, L_tmpnam);
return s;
}