-/* Copyright (C) 1991-1999, 2000 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
+/* tempname.c - generate the name of a temporary file.
- 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.
+ Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+ 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
- The GNU C Library is distributed in the hope that it will be useful,
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ This program 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.
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU 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. */
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation,
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#if HAVE_CONFIG_H
# include <config.h>
# define __GT_NOCREATE 3
#endif
-#if STDC_HEADERS || _LIBC
-# include <stddef.h>
-# include <stdlib.h>
-# include <string.h>
-#endif
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
#if HAVE_FCNTL_H || _LIBC
# include <fcntl.h>
#if HAVE_STDINT_H || _LIBC
# include <stdint.h>
#endif
+#if HAVE_INTTYPES_H
+# include <inttypes.h>
+#endif
#if HAVE_UNISTD_H || _LIBC
# include <unistd.h>
# define __secure_getenv getenv
#endif
+#ifdef _LIBC
+# include <hp-timing.h>
+# if HP_TIMING_AVAIL
+# define RANDOM_BITS(Var) \
+ if (__builtin_expect (value == UINT64_C (0), 0)) \
+ { \
+ /* If this is the first time this function is used initialize \
+ the variable we accumulate the value in to some somewhat \
+ random value. If we'd not do this programs at startup time \
+ might have a reduced set of possible names, at least on slow \
+ machines. */ \
+ struct timeval tv; \
+ __gettimeofday (&tv, NULL); \
+ value = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec; \
+ } \
+ HP_TIMING_NOW (Var)
+# endif
+#endif
+
+/* Use the widest available unsigned type if uint64_t is not
+ available. The algorithm below extracts a number less than 62**6
+ (approximately 2**35.725) from uint64_t, so ancient hosts where
+ uintmax_t is only 32 bits lose about 3.725 bits of randomness,
+ which is better than not having mkstemp at all. */
+#if !defined UINT64_MAX && !defined uint64_t
+# define uint64_t uintmax_t
+#endif
+
/* Return nonzero if DIR is an existent directory. */
static int
direxists (const char *dir)
char *XXXXXX;
static uint64_t value;
uint64_t random_time_bits;
- int count, fd = -1;
+ unsigned int count;
+ int fd = -1;
int save_errno = errno;
struct_stat64 st;
+ /* A lower bound on the number of temporary files to attempt to
+ generate. The maximum total number of temporary file names that
+ can exist for a given template is 62**6. It should never be
+ necessary to try all these combinations. Instead if a reasonable
+ number of names is tried (we define reasonable as 62**3) fail to
+ give the system administrator the chance to remove the problems. */
+ unsigned int attempts_min = 62 * 62 * 62;
+
+ /* The number of times to attempt to generate a temporary file. To
+ conform to POSIX, this must be no smaller than TMP_MAX. */
+ unsigned int attempts = attempts_min < TMP_MAX ? TMP_MAX : attempts_min;
+
len = strlen (tmpl);
if (len < 6 || strcmp (&tmpl[len - 6], "XXXXXX"))
{
XXXXXX = &tmpl[len - 6];
/* Get some more or less random data. */
-#if HAVE_GETTIMEOFDAY || _LIBC
+#ifdef RANDOM_BITS
+ RANDOM_BITS (random_time_bits);
+#else
+# if HAVE_GETTIMEOFDAY || _LIBC
{
struct timeval tv;
__gettimeofday (&tv, NULL);
random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec;
}
-#else
+# else
random_time_bits = time (NULL);
+# endif
#endif
value += random_time_bits ^ __getpid ();
- for (count = 0; count < TMP_MAX; value += 7777, ++count)
+ for (count = 0; count < attempts; value += 7777, ++count)
{
uint64_t v = value;
projects / gnulib.git / blobdiff