[ec24a37] | 1 | /* Copyright (C) 1991, 1992, 1996, 1998, 2004 Free Software Foundation, Inc. |
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| 2 | This file is derived from mkstemp.c from the GNU C Library. |
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| 3 | |
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| 4 | The GNU C Library is free software; you can redistribute it and/or |
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| 5 | modify it under the terms of the GNU Library General Public License as |
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| 6 | published by the Free Software Foundation; either version 2 of the |
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| 7 | License, or (at your option) any later version. |
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| 8 | |
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| 9 | The GNU C Library is distributed in the hope that it will be useful, |
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 12 | Library General Public License for more details. |
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| 13 | |
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| 14 | You should have received a copy of the GNU Library General Public |
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| 15 | License along with the GNU C Library; see the file COPYING.LIB. If not, |
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| 16 | write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, |
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| 17 | Boston, MA 02110-1301, USA. */ |
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| 18 | |
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| 19 | #ifdef HAVE_CONFIG_H |
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| 20 | #include "config.h" |
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| 21 | #endif |
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| 22 | |
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| 23 | #include <sys/types.h> |
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| 24 | #ifdef HAVE_STDLIB_H |
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| 25 | #include <stdlib.h> |
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| 26 | #endif |
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| 27 | #ifdef HAVE_STRING_H |
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| 28 | #include <string.h> |
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| 29 | #endif |
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| 30 | #include <errno.h> |
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| 31 | #include <stdio.h> |
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| 32 | #include <fcntl.h> |
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| 33 | #ifdef HAVE_UNISTD_H |
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| 34 | #include <unistd.h> |
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| 35 | #endif |
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| 36 | #ifdef HAVE_SYS_TIME_H |
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| 37 | #include <sys/time.h> |
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| 38 | #endif |
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| 39 | #include "ansidecl.h" |
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| 40 | |
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| 41 | /* We need to provide a type for gcc_uint64_t. */ |
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| 42 | #ifdef __GNUC__ |
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| 43 | __extension__ typedef unsigned long long gcc_uint64_t; |
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| 44 | #else |
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| 45 | typedef unsigned long gcc_uint64_t; |
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| 46 | #endif |
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| 47 | |
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| 48 | #ifndef TMP_MAX |
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| 49 | #define TMP_MAX 16384 |
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| 50 | #endif |
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| 51 | |
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| 52 | #ifndef O_BINARY |
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| 53 | # define O_BINARY 0 |
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| 54 | #endif |
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| 55 | |
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| 56 | /* |
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| 57 | |
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| 58 | @deftypefn Replacement int mkstemps (char *@var{pattern}, int @var{suffix_len}) |
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| 59 | |
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| 60 | Generate a unique temporary file name from @var{pattern}. |
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| 61 | @var{pattern} has the form: |
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| 62 | |
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| 63 | @example |
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| 64 | @var{path}/ccXXXXXX@var{suffix} |
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| 65 | @end example |
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| 66 | |
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| 67 | @var{suffix_len} tells us how long @var{suffix} is (it can be zero |
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| 68 | length). The last six characters of @var{pattern} before @var{suffix} |
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| 69 | must be @samp{XXXXXX}; they are replaced with a string that makes the |
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| 70 | filename unique. Returns a file descriptor open on the file for |
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| 71 | reading and writing. |
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| 72 | |
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| 73 | @end deftypefn |
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| 74 | |
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| 75 | */ |
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| 76 | |
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| 77 | int |
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| 78 | mkstemps (char *pattern, int suffix_len) |
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| 79 | { |
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| 80 | static const char letters[] |
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| 81 | = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; |
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| 82 | static gcc_uint64_t value; |
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| 83 | #ifdef HAVE_GETTIMEOFDAY |
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| 84 | struct timeval tv; |
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| 85 | #endif |
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| 86 | char *XXXXXX; |
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| 87 | size_t len; |
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| 88 | int count; |
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| 89 | |
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| 90 | len = strlen (pattern); |
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| 91 | |
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| 92 | if ((int) len < 6 + suffix_len |
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| 93 | || strncmp (&pattern[len - 6 - suffix_len], "XXXXXX", 6)) |
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| 94 | { |
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| 95 | return -1; |
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| 96 | } |
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| 97 | |
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| 98 | XXXXXX = &pattern[len - 6 - suffix_len]; |
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| 99 | |
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| 100 | #ifdef HAVE_GETTIMEOFDAY |
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| 101 | /* Get some more or less random data. */ |
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| 102 | gettimeofday (&tv, NULL); |
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| 103 | value += ((gcc_uint64_t) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid (); |
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| 104 | #else |
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| 105 | value += getpid (); |
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| 106 | #endif |
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| 107 | |
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| 108 | for (count = 0; count < TMP_MAX; ++count) |
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| 109 | { |
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| 110 | gcc_uint64_t v = value; |
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| 111 | int fd; |
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| 112 | |
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| 113 | /* Fill in the random bits. */ |
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| 114 | XXXXXX[0] = letters[v % 62]; |
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| 115 | v /= 62; |
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| 116 | XXXXXX[1] = letters[v % 62]; |
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| 117 | v /= 62; |
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| 118 | XXXXXX[2] = letters[v % 62]; |
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| 119 | v /= 62; |
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| 120 | XXXXXX[3] = letters[v % 62]; |
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| 121 | v /= 62; |
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| 122 | XXXXXX[4] = letters[v % 62]; |
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| 123 | v /= 62; |
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| 124 | XXXXXX[5] = letters[v % 62]; |
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| 125 | |
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| 126 | fd = open (pattern, O_BINARY|O_RDWR|O_CREAT|O_EXCL, 0600); |
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| 127 | if (fd >= 0) |
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| 128 | /* The file does not exist. */ |
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| 129 | return fd; |
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| 130 | if (errno != EEXIST |
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| 131 | #ifdef EISDIR |
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| 132 | && errno != EISDIR |
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| 133 | #endif |
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| 134 | ) |
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| 135 | /* Fatal error (EPERM, ENOSPC etc). Doesn't make sense to loop. */ |
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| 136 | break; |
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| 137 | |
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| 138 | /* This is a random value. It is only necessary that the next |
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| 139 | TMP_MAX values generated by adding 7777 to VALUE are different |
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| 140 | with (module 2^32). */ |
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| 141 | value += 7777; |
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| 142 | } |
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| 143 | |
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| 144 | /* We return the null string if we can't find a unique file name. */ |
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| 145 | pattern[0] = '\0'; |
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| 146 | return -1; |
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| 147 | } |
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