1 | /* Copyright (C) 1999, 2001-2002 Free Software Foundation, Inc. |
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2 | This file is part of 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., 59 Temple Place - Suite 330, |
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17 | Boston, MA 02111-1307, USA. */ |
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18 | |
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19 | /* Extracted from misc/mkdtemp.c and sysdeps/posix/tempname.c. */ |
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20 | |
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21 | #ifdef HAVE_CONFIG_H |
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22 | # include "config.h" |
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23 | #endif |
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24 | |
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25 | /* Specification. */ |
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26 | #include "mkdtemp.h" |
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27 | |
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28 | #include <errno.h> |
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29 | #ifndef __set_errno |
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30 | # define __set_errno(Val) errno = (Val) |
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31 | #endif |
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32 | |
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33 | #include <stddef.h> |
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34 | #include <stdlib.h> |
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35 | #include <string.h> |
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36 | |
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37 | #include <stdio.h> |
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38 | #ifndef TMP_MAX |
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39 | # define TMP_MAX 238328 |
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40 | #endif |
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41 | |
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42 | #if HAVE_STDINT_H_WITH_UINTMAX || _LIBC |
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43 | # include <stdint.h> |
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44 | #endif |
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45 | |
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46 | #if HAVE_INTTYPES_H_WITH_UINTMAX || _LIBC |
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47 | # include <inttypes.h> |
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48 | #endif |
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49 | |
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50 | #if HAVE_UNISTD_H || _LIBC |
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51 | # include <unistd.h> |
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52 | #endif |
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53 | |
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54 | #if HAVE_GETTIMEOFDAY || _LIBC |
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55 | # if HAVE_SYS_TIME_H || _LIBC |
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56 | # include <sys/time.h> |
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57 | # endif |
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58 | #else |
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59 | # if HAVE_TIME_H || _LIBC |
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60 | # include <time.h> |
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61 | # endif |
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62 | #endif |
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63 | |
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64 | #include <sys/stat.h> |
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65 | #if STAT_MACROS_BROKEN |
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66 | # undef S_ISDIR |
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67 | #endif |
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68 | #if !defined S_ISDIR && defined S_IFDIR |
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69 | # define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR) |
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70 | #endif |
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71 | #if !S_IRUSR && S_IREAD |
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72 | # define S_IRUSR S_IREAD |
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73 | #endif |
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74 | #if !S_IRUSR |
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75 | # define S_IRUSR 00400 |
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76 | #endif |
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77 | #if !S_IWUSR && S_IWRITE |
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78 | # define S_IWUSR S_IWRITE |
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79 | #endif |
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80 | #if !S_IWUSR |
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81 | # define S_IWUSR 00200 |
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82 | #endif |
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83 | #if !S_IXUSR && S_IEXEC |
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84 | # define S_IXUSR S_IEXEC |
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85 | #endif |
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86 | #if !S_IXUSR |
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87 | # define S_IXUSR 00100 |
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88 | #endif |
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89 | |
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90 | #if !_LIBC |
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91 | # define __getpid getpid |
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92 | # define __gettimeofday gettimeofday |
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93 | # define __mkdir mkdir |
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94 | #endif |
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95 | |
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96 | /* Use the widest available unsigned type if uint64_t is not |
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97 | available. The algorithm below extracts a number less than 62**6 |
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98 | (approximately 2**35.725) from uint64_t, so ancient hosts where |
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99 | uintmax_t is only 32 bits lose about 3.725 bits of randomness, |
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100 | which is better than not having mkstemp at all. */ |
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101 | #if !defined UINT64_MAX && !defined uint64_t |
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102 | # define uint64_t uintmax_t |
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103 | #endif |
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104 | |
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105 | /* These are the characters used in temporary filenames. */ |
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106 | static const char letters[] = |
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107 | "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; |
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108 | |
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109 | /* Generate a temporary file name based on TMPL. TMPL must match the |
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110 | rules for mk[s]temp (i.e. end in "XXXXXX"). The name constructed |
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111 | does not exist at the time of the call to __gen_tempname. TMPL is |
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112 | overwritten with the result. |
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113 | |
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114 | KIND is: |
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115 | __GT_DIR: create a directory, which will be mode 0700. |
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116 | |
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117 | We use a clever algorithm to get hard-to-predict names. */ |
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118 | static int |
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119 | gen_tempname (tmpl) |
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120 | char *tmpl; |
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121 | { |
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122 | int len; |
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123 | char *XXXXXX; |
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124 | static uint64_t value; |
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125 | uint64_t random_time_bits; |
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126 | int count, fd = -1; |
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127 | int save_errno = errno; |
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128 | |
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129 | len = strlen (tmpl); |
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130 | if (len < 6 || strcmp (&tmpl[len - 6], "XXXXXX")) |
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131 | { |
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132 | __set_errno (EINVAL); |
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133 | return -1; |
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134 | } |
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135 | |
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136 | /* This is where the Xs start. */ |
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137 | XXXXXX = &tmpl[len - 6]; |
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138 | |
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139 | /* Get some more or less random data. */ |
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140 | #ifdef RANDOM_BITS |
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141 | RANDOM_BITS (random_time_bits); |
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142 | #else |
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143 | # if HAVE_GETTIMEOFDAY || _LIBC |
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144 | { |
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145 | struct timeval tv; |
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146 | __gettimeofday (&tv, NULL); |
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147 | random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec; |
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148 | } |
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149 | # else |
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150 | random_time_bits = time (NULL); |
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151 | # endif |
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152 | #endif |
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153 | value += random_time_bits ^ __getpid (); |
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154 | |
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155 | for (count = 0; count < TMP_MAX; value += 7777, ++count) |
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156 | { |
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157 | uint64_t v = value; |
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158 | |
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159 | /* Fill in the random bits. */ |
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160 | XXXXXX[0] = letters[v % 62]; |
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161 | v /= 62; |
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162 | XXXXXX[1] = letters[v % 62]; |
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163 | v /= 62; |
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164 | XXXXXX[2] = letters[v % 62]; |
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165 | v /= 62; |
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166 | XXXXXX[3] = letters[v % 62]; |
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167 | v /= 62; |
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168 | XXXXXX[4] = letters[v % 62]; |
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169 | v /= 62; |
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170 | XXXXXX[5] = letters[v % 62]; |
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171 | |
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172 | fd = __mkdir (tmpl, S_IRUSR | S_IWUSR | S_IXUSR); |
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173 | |
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174 | if (fd >= 0) |
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175 | { |
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176 | __set_errno (save_errno); |
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177 | return fd; |
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178 | } |
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179 | else if (errno != EEXIST) |
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180 | return -1; |
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181 | } |
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182 | |
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183 | /* We got out of the loop because we ran out of combinations to try. */ |
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184 | __set_errno (EEXIST); |
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185 | return -1; |
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186 | } |
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187 | |
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188 | /* Generate a unique temporary directory from TEMPLATE. |
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189 | The last six characters of TEMPLATE must be "XXXXXX"; |
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190 | they are replaced with a string that makes the filename unique. |
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191 | The directory is created, mode 700, and its name is returned. |
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192 | (This function comes from OpenBSD.) */ |
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193 | char * |
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194 | mkdtemp (template) |
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195 | char *template; |
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196 | { |
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197 | if (gen_tempname (template)) |
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198 | return NULL; |
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199 | else |
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200 | return template; |
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201 | } |
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