/* 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, see <http://www.gnu.org/licenses/>. */ #include <stdio.h> #include <string.h> #include "../misc/internals/tempname.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 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, 0, 0), 0)) return NULL; if (s == NULL) return (char *) memcpy (tmpnam_buffer, tmpbuf, L_tmpnam); return s; }