1 /* Copyright (C) 1999, 2001-2003, 2006 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License along
15 with this program; if not, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
18 /* Extracted from misc/mkdtemp.c and sysdeps/posix/tempname.c. */
29 # define __set_errno(Val) errno = (Val)
38 # define TMP_MAX 238328
41 #if HAVE_STDINT_H || _LIBC
45 # include <inttypes.h>
50 #if HAVE_GETTIMEOFDAY || _LIBC
51 # if HAVE_SYS_TIME_H || _LIBC
52 # include <sys/time.h>
55 # if HAVE_TIME_H || _LIBC
61 #if !defined S_ISDIR && defined S_IFDIR
62 # define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)
64 #if !S_IRUSR && S_IREAD
65 # define S_IRUSR S_IREAD
68 # define S_IRUSR 00400
70 #if !S_IWUSR && S_IWRITE
71 # define S_IWUSR S_IWRITE
74 # define S_IWUSR 00200
76 #if !S_IXUSR && S_IEXEC
77 # define S_IXUSR S_IEXEC
80 # define S_IXUSR 00100
85 /* mingw's _mkdir() function has 1 argument, but we pass 2 arguments.
86 Therefore we have to disable the argument count checking. */
87 # define mkdir ((int (*)()) _mkdir)
91 # define __getpid getpid
92 # define __gettimeofday gettimeofday
93 # define __mkdir mkdir
96 /* Use the widest available unsigned type if uint64_t is not
97 available. The algorithm below extracts a number less than 62**6
98 (approximately 2**35.725) from uint64_t, so ancient hosts where
99 uintmax_t is only 32 bits lose about 3.725 bits of randomness,
100 which is better than not having mkstemp at all. */
101 #if !defined UINT64_MAX && !defined uint64_t
102 # define uint64_t uintmax_t
105 /* These are the characters used in temporary filenames. */
106 static const char letters[] =
107 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
109 /* Generate a temporary file name based on TMPL. TMPL must match the
110 rules for mk[s]temp (i.e. end in "XXXXXX"). The name constructed
111 does not exist at the time of the call to __gen_tempname. TMPL is
112 overwritten with the result.
115 __GT_DIR: create a directory, which will be mode 0700.
117 We use a clever algorithm to get hard-to-predict names. */
119 gen_tempname (char *tmpl)
123 static uint64_t value;
124 uint64_t random_time_bits;
126 int save_errno = errno;
129 if (len < 6 || strcmp (&tmpl[len - 6], "XXXXXX"))
131 __set_errno (EINVAL);
135 /* This is where the Xs start. */
136 XXXXXX = &tmpl[len - 6];
138 /* Get some more or less random data. */
140 RANDOM_BITS (random_time_bits);
142 # if HAVE_GETTIMEOFDAY || _LIBC
145 __gettimeofday (&tv, NULL);
146 random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec;
149 random_time_bits = time (NULL);
152 value += random_time_bits ^ __getpid ();
154 for (count = 0; count < TMP_MAX; value += 7777, ++count)
158 /* Fill in the random bits. */
159 XXXXXX[0] = letters[v % 62];
161 XXXXXX[1] = letters[v % 62];
163 XXXXXX[2] = letters[v % 62];
165 XXXXXX[3] = letters[v % 62];
167 XXXXXX[4] = letters[v % 62];
169 XXXXXX[5] = letters[v % 62];
171 fd = __mkdir (tmpl, S_IRUSR | S_IWUSR | S_IXUSR);
175 __set_errno (save_errno);
178 else if (errno != EEXIST)
182 /* We got out of the loop because we ran out of combinations to try. */
183 __set_errno (EEXIST);
187 /* Generate a unique temporary directory from TEMPLATE.
188 The last six characters of TEMPLATE must be "XXXXXX";
189 they are replaced with a string that makes the filename unique.
190 The directory is created, mode 700, and its name is returned.
191 (This function comes from OpenBSD.) */
193 mkdtemp (char *template)
195 if (gen_tempname (template))