1 /* Copyright (C) 1991, 1992, 1996, 1998, 2004 Free Software Foundation, Inc.
2 This file is derived from mkstemp.c from the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Library General Public License as
6 published by the Free Software Foundation; either version 2 of the
7 License, or (at your option) any later version.
8
9 The GNU C Library 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 GNU
12 Library General Public License for more details.
13
14 You should have received a copy of the GNU Library General Public
15 License along with the GNU C Library; see the file COPYING.LIB. If not,
16 write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
17 Boston, MA 02110-1301, USA. */
18 /*
19 * This file was copied on 2013-08-03 from:
20 * https://raw.github.com/mirrors/gcc/master/libiberty/mkstemps.c
21 */
22
23 #ifdef HAVE_CONFIG_H
24 #include "config.h"
25 #endif
26
27 #include "compat.h"
28
29 #include <sys/types.h>
30 #ifdef HAVE_STDLIB_H
31 #include <stdlib.h>
32 #endif
33 #ifdef HAVE_STRING_H
34 #include <string.h>
35 #endif
36 #include <errno.h>
37 #include <stdio.h>
38 #include <fcntl.h>
39 #ifdef HAVE_UNISTD_H
40 #include <unistd.h>
41 #endif
42 #ifdef HAVE_SYS_TIME_H
43 #include <sys/time.h>
44 #endif
45
46 /* We need to provide a type for gcc_uint64_t. */
47 #ifdef __GNUC__
48 __extension__ typedef unsigned long long gcc_uint64_t;
49 #else
50 typedef unsigned long gcc_uint64_t;
51 #endif
52
53 #ifndef TMP_MAX
54 #define TMP_MAX 16384
55 #endif
56
57 #ifndef O_BINARY
58 # define O_BINARY 0
59 #endif
60
61 /*
62
63 @deftypefn Replacement int mkstemps (char *@var{pattern}, int @var{suffix_len})
64
65 Generate a unique temporary file name from @var{pattern}.
66 @var{pattern} has the form:
67
68 @example
69 @var{path}/ccXXXXXX@var{suffix}
70 @end example
71
72 @var{suffix_len} tells us how long @var{suffix} is (it can be zero
73 length). The last six characters of @var{pattern} before @var{suffix}
74 must be @samp{XXXXXX}; they are replaced with a string that makes the
75 filename unique. Returns a file descriptor open on the file for
76 reading and writing.
77
78 @end deftypefn
79
80 */
81
82 int
compat_mkstemps(char * pattern,int suffix_len)83 compat_mkstemps (char *pattern, int suffix_len)
84 {
85 static const char letters[]
86 = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
87 static gcc_uint64_t value;
88 #ifdef HAVE_GETTIMEOFDAY
89 struct timeval tv;
90 #endif
91 char *XXXXXX;
92 size_t len;
93 int count;
94
95 len = strlen (pattern);
96
97 if ((int) len < 6 + suffix_len
98 || strncmp (&pattern[len - 6 - suffix_len], "XXXXXX", 6))
99 {
100 return -1;
101 }
102
103 XXXXXX = &pattern[len - 6 - suffix_len];
104
105 #ifdef HAVE_GETTIMEOFDAY
106 /* Get some more or less random data. */
107 gettimeofday (&tv, NULL);
108 value += ((gcc_uint64_t) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid ();
109 #else
110 value += getpid ();
111 #endif
112
113 for (count = 0; count < TMP_MAX; ++count)
114 {
115 gcc_uint64_t v = value;
116 int fd;
117
118 /* Fill in the random bits. */
119 XXXXXX[0] = letters[v % 62];
120 v /= 62;
121 XXXXXX[1] = letters[v % 62];
122 v /= 62;
123 XXXXXX[2] = letters[v % 62];
124 v /= 62;
125 XXXXXX[3] = letters[v % 62];
126 v /= 62;
127 XXXXXX[4] = letters[v % 62];
128 v /= 62;
129 XXXXXX[5] = letters[v % 62];
130
131 fd = open (pattern, O_BINARY|O_RDWR|O_CREAT|O_EXCL, 0600);
132 if (fd >= 0)
133 /* The file does not exist. */
134 return fd;
135 if (errno != EEXIST
136 #ifdef EISDIR
137 && errno != EISDIR
138 #endif
139 )
140 /* Fatal error (EPERM, ENOSPC etc). Doesn't make sense to loop. */
141 break;
142
143 /* This is a random value. It is only necessary that the next
144 TMP_MAX values generated by adding 7777 to VALUE are different
145 with (module 2^32). */
146 value += 7777;
147 }
148
149 /* We return the null string if we can't find a unique file name. */
150 pattern[0] = '\0';
151 return -1;
152 }
153