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98cb9664 | 1 | /* Copyright (C) 1991, 1992, 1996, 1998, 2001 Free Software Foundation, Inc. |
23cc5968 MV |
2 | This file is derived from mkstemps.c from the GNU Libiberty Library |
3 | which in turn is derived from the GNU C Library. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Library General Public License as | |
7 | published by the Free Software Foundation; either version 2 of the | |
8 | License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Library General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Library General Public | |
16 | License along with the GNU C Library; see the file COPYING.LIB. If not, | |
17 | write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
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18 | Boston, MA 02111-1307, USA. |
19 | ||
20 | As a special exception, the Free Software Foundation gives permission | |
21 | for additional uses of the text contained in its release of GUILE. | |
22 | ||
23 | The exception is that, if you link the GUILE library with other files | |
24 | to produce an executable, this does not by itself cause the | |
25 | resulting executable to be covered by the GNU General Public License. | |
26 | Your use of that executable is in no way restricted on account of | |
27 | linking the GUILE library code into it. | |
28 | ||
29 | This exception does not however invalidate any other reasons why | |
30 | the executable file might be covered by the GNU General Public License. | |
31 | ||
32 | This exception applies only to the code released by the | |
33 | Free Software Foundation under the name GUILE. If you copy | |
34 | code from other Free Software Foundation releases into a copy of | |
35 | GUILE, as the General Public License permits, the exception does | |
36 | not apply to the code that you add in this way. To avoid misleading | |
37 | anyone as to the status of such modified files, you must delete | |
38 | this exception notice from them. | |
39 | ||
40 | If you write modifications of your own for GUILE, it is your choice | |
41 | whether to permit this exception to apply to your modifications. | |
42 | If you do not wish that, delete this exception notice. */ | |
23cc5968 | 43 | |
98cb9664 | 44 | #include "libguile/scmconfig.h" |
23cc5968 MV |
45 | |
46 | #ifdef HAVE_STDLIB_H | |
47 | #include <stdlib.h> | |
48 | #endif | |
49 | #ifdef HAVE_STRING_H | |
50 | #include <string.h> | |
51 | #endif | |
52 | #include <errno.h> | |
53 | #include <stdio.h> | |
54 | #include <fcntl.h> | |
55 | #ifdef HAVE_UNISTD_H | |
56 | #include <unistd.h> | |
57 | #endif | |
58 | #ifdef HAVE_SYS_TIME_H | |
59 | #include <sys/time.h> | |
60 | #endif | |
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61 | #ifdef __MINGW32__ |
62 | #include <process.h> | |
63 | #endif | |
23cc5968 MV |
64 | |
65 | /* We need to provide a type for gcc_uint64_t. */ | |
66 | #ifdef __GNUC__ | |
67 | typedef unsigned long long gcc_uint64_t; | |
68 | #else | |
69 | typedef unsigned long gcc_uint64_t; | |
70 | #endif | |
71 | ||
72 | #ifndef TMP_MAX | |
73 | #define TMP_MAX 16384 | |
74 | #endif | |
75 | ||
76 | /* Generate a unique temporary file name from TEMPLATE. | |
77 | ||
78 | TEMPLATE has the form: | |
79 | ||
80 | <path>/ccXXXXXX | |
81 | ||
82 | The last six characters of TEMPLATE must be "XXXXXX"; they are | |
83 | replaced with a string that makes the filename unique. | |
84 | ||
85 | Returns a file descriptor open on the file for reading and writing. */ | |
86 | int | |
87 | mkstemp (template) | |
88 | char *template; | |
89 | { | |
90 | static const char letters[] | |
91 | = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; | |
92 | static gcc_uint64_t value; | |
93 | #ifdef HAVE_GETTIMEOFDAY | |
94 | struct timeval tv; | |
95 | #endif | |
96 | char *XXXXXX; | |
97 | size_t len; | |
98 | int count; | |
99 | ||
100 | len = strlen (template); | |
101 | ||
102 | if ((int) len < 6 | |
103 | || strncmp (&template[len - 6], "XXXXXX", 6)) | |
104 | { | |
105 | return -1; | |
106 | } | |
107 | ||
108 | XXXXXX = &template[len - 6]; | |
109 | ||
110 | #ifdef HAVE_GETTIMEOFDAY | |
111 | /* Get some more or less random data. */ | |
112 | gettimeofday (&tv, NULL); | |
113 | value += ((gcc_uint64_t) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid (); | |
114 | #else | |
115 | value += getpid (); | |
116 | #endif | |
117 | ||
118 | for (count = 0; count < TMP_MAX; ++count) | |
119 | { | |
120 | gcc_uint64_t v = value; | |
121 | int fd; | |
122 | ||
123 | /* Fill in the random bits. */ | |
124 | XXXXXX[0] = letters[v % 62]; | |
125 | v /= 62; | |
126 | XXXXXX[1] = letters[v % 62]; | |
127 | v /= 62; | |
128 | XXXXXX[2] = letters[v % 62]; | |
129 | v /= 62; | |
130 | XXXXXX[3] = letters[v % 62]; | |
131 | v /= 62; | |
132 | XXXXXX[4] = letters[v % 62]; | |
133 | v /= 62; | |
134 | XXXXXX[5] = letters[v % 62]; | |
135 | ||
136 | fd = open (template, O_RDWR|O_CREAT|O_EXCL, 0600); | |
137 | if (fd >= 0) | |
138 | /* The file does not exist. */ | |
139 | return fd; | |
140 | ||
141 | /* This is a random value. It is only necessary that the next | |
142 | TMP_MAX values generated by adding 7777 to VALUE are different | |
143 | with (module 2^32). */ | |
144 | value += 7777; | |
145 | } | |
146 | ||
147 | /* We return the null string if we can't find a unique file name. */ | |
148 | template[0] = '\0'; | |
149 | return -1; | |
150 | } |