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428
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1 /*
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2 * realpath.c -- canonicalize pathname by removing symlinks
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3 * Copyright (C) 1993 Rick Sladkey <jrs@world.std.com>
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771
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4 * Copyright (C) 2001 Ben Wing.
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428
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5 *
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6
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7 This file is part of XEmacs.
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8
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9 XEmacs is free software; you can redistribute it and/or modify it
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10 under the terms of the GNU General Public License as published by the
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11 Free Software Foundation; either version 2, or (at your option) any
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12 later version.
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13
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14 XEmacs is distributed in the hope that it will be useful, but WITHOUT
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15 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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17 for more details.
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18
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19 You should have received a copy of the GNU General Public License
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20 along with XEmacs; see the file COPYING. If not, write to
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21 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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22 Boston, MA 02111-1307, USA. */
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23
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24 /* Synched up with: Not in FSF. */
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25
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771
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26 /* This file has been Mule-ized, June 2001 by Ben Wing.
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27
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28 Everything in this file now works in terms of internal, not external,
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29 data. This is the only way to be safe, and it makes the code cleaner. */
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30
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428
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31 #include <config.h>
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446
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32 #include "lisp.h"
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442
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33
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558
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34 #include "sysfile.h"
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428
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35
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771
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36 #define MAX_READLINKS 32
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37
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446
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38 /* First char after start of absolute filename. */
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39 #define ABS_START(name) (name + ABS_LENGTH (name))
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40
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41 #if defined (WIN32_NATIVE)
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42 /* Length of start of absolute filename. */
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771
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43 # define ABS_LENGTH(name) (mswindows_abs_start (name))
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44 static int mswindows_abs_start (const Intbyte *name);
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45 # define readlink_and_correct_case mswindows_readlink_and_correct_case
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446
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46 #else
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47 # ifdef CYGWIN
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48 # define ABS_LENGTH(name) (IS_DIRECTORY_SEP (*name) ? \
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49 (IS_DIRECTORY_SEP (name[1]) ? 2 : 1) : 0)
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771
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50 # define readlink_and_correct_case cygwin_readlink_and_correct_case
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446
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51 # else
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52 # define ABS_LENGTH(name) (IS_DIRECTORY_SEP (*name) ? 1 : 0)
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771
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53 # define readlink_and_correct_case qxe_readlink
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446
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54 # endif /* CYGWIN */
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55 #endif /* WIN32_NATIVE */
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56
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57 #if defined (WIN32_NATIVE) || defined (CYGWIN)
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58 #include "syswindows.h"
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771
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59 /* "Emulate" readlink on mswindows - finds real name (i.e. correct
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60 case) of a file. (#### "readlink" is used extremely misleadingly
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61 here. This is much more like "truename"!) UNC servers and shares
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62 are lower-cased. Directories must be given without trailing
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63 '/'. One day, this could read Win2K's reparse points. */
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446
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64 static int
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771
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65 mswindows_readlink_and_correct_case (const Intbyte *name, Intbyte *buf,
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66 int size)
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446
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67 {
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68 int len = 0;
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69 int err = 0;
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771
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70 const Intbyte *lastname;
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446
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71 int count = 0;
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771
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72 const Intbyte *tmp;
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73 DECLARE_EISTRING (result);
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446
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74
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75 assert (*name);
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76
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77 /* Sort of check we have a valid filename. */
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771
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78 if (qxestrpbrk (name, "*?|<>\"") || qxestrlen (name) >= PATH_MAX)
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446
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79 {
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80 errno = EIO;
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81 return -1;
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82 }
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83
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84 /* Find start of filename */
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771
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85 lastname = name + qxestrlen (name);
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446
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86 while (lastname > name && !IS_DIRECTORY_SEP (lastname[-1]))
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87 --lastname;
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88
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89 /* Count slashes in unc path */
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90 if (ABS_LENGTH (name) == 2)
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91 for (tmp = name; *tmp; tmp++)
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92 if (IS_DIRECTORY_SEP (*tmp))
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93 count++;
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94
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95 if (count >= 2 && count < 4)
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96 {
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771
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97 eicpy_rawz (result, lastname);
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98 eilwr (result);
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446
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99 }
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100 else
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771
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101 {
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102 WIN32_FIND_DATAW find_data;
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103 Extbyte *nameext;
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104 HANDLE dir_handle;
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446
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105
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771
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106 C_STRING_TO_TSTR (name, nameext);
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107 dir_handle = qxeFindFirstFile (nameext, &find_data);
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108 if (dir_handle == INVALID_HANDLE_VALUE)
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446
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109 {
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771
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110 errno = ENOENT;
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111 return -1;
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446
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112 }
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771
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113 eicpy_ext (result, (Extbyte *) find_data.cFileName, Qmswindows_tstr);
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114 FindClose (dir_handle);
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115 }
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116
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117 if ((len = eilen (result)) < size)
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118 {
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119 DECLARE_EISTRING (eilastname);
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120
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121 eicpy_rawz (eilastname, lastname);
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122 if (eicmp_ei (eilastname, result) == 0)
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123 /* Signal that the name is already OK. */
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124 err = EINVAL;
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446
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125 else
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771
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126 memcpy (buf, eidata (result), len + 1);
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446
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127 }
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128 else
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129 err = ENAMETOOLONG;
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446
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130
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131 errno = err;
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132 return err ? -1 : len;
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133 }
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134 #endif /* WIN32_NATIVE || CYGWIN */
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135
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136 #ifdef CYGWIN
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137 /* Call readlink and try to find out the correct case for the file. */
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138 static int
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771
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139 cygwin_readlink_and_correct_case (const Intbyte *name, Intbyte *buf,
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140 int size)
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446
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141 {
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771
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142 int n = qxe_readlink (name, buf, size);
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462
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143 if (n < 0 && errno == EINVAL)
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446
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144 {
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145 /* The file may exist, but isn't a symlink. Try to find the
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146 right name. */
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771
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147 Intbyte *tmp =
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148 (Intbyte *) alloca (cygwin_posix_to_win32_path_list_buf_size
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149 ((char *) name));
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150 cygwin_posix_to_win32_path_list ((char *) name, (char *) tmp);
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151 n = mswindows_readlink_and_correct_case (tmp, buf, size);
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446
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152 }
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153 return n;
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154 }
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155 #endif /* CYGWIN */
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156
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157 #ifdef WIN32_NATIVE
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158 #ifndef ELOOP
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159 #define ELOOP 10062 /* = WSAELOOP in winsock.h */
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160 #endif
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161 /* Length of start of absolute filename. */
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162 static int
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771
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163 mswindows_abs_start (const Intbyte *name)
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446
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164 {
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165 if (isalpha (*name) && IS_DEVICE_SEP (name[1])
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166 && IS_DIRECTORY_SEP (name[2]))
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167 return 3;
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168 else if (IS_DIRECTORY_SEP (*name))
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169 return IS_DIRECTORY_SEP (name[1]) ? 2 : 1;
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170 else
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171 return 0;
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172 }
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173 #endif /* WIN32_NATIVE */
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174
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771
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175 /* Mule Note: This function works with and returns
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176 internally-formatted strings. */
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440
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177
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771
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178 Intbyte *
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179 qxe_realpath (const Intbyte *path, Intbyte *resolved_path)
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428
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180 {
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771
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181 Intbyte copy_path[PATH_MAX];
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182 Intbyte *new_path = resolved_path;
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183 Intbyte *max_path;
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184 #if defined (HAVE_READLINK) || defined (WIN32_NATIVE)
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428
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185 int readlinks = 0;
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771
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186 Intbyte link_path[PATH_MAX];
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428
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187 int n;
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446
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188 int abslen = ABS_LENGTH (path);
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428
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189 #endif
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190
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191 /* Make a copy of the source path since we may need to modify it. */
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771
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192 qxestrcpy (copy_path, path);
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428
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193 path = copy_path;
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194 max_path = copy_path + PATH_MAX - 2;
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446
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195
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442
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196 #ifdef WIN32_NATIVE
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446
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197 /* Check for c:/... or //server/... */
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198 if (abslen == 2 || abslen == 3)
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428
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199 {
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771
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200 qxestrncpy (new_path, path, abslen);
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462
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201 /* Make sure drive letter is lowercased. */
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202 if (abslen == 3)
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203 *new_path = tolower (*new_path);
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446
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204 new_path += abslen;
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205 path += abslen;
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428
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206 }
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446
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207 /* No drive letter, but a beginning slash? Prepend drive letter. */
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208 else if (abslen == 1)
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428
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209 {
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771
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210 get_initial_directory (new_path, PATH_MAX - 1);
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428
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211 new_path += 3;
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212 path++;
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213 }
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446
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214 /* Just a path name, prepend the current directory */
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428
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215 else
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216 {
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771
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217 get_initial_directory (new_path, PATH_MAX - 1);
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218 new_path += qxestrlen (new_path);
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446
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219 if (!IS_DIRECTORY_SEP (new_path[-1]))
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220 *new_path++ = DIRECTORY_SEP;
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428
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221 }
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222 #else
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771
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223 /* If it's a relative pathname use get_initial_directory for starters. */
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446
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224 if (abslen == 0)
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428
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225 {
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771
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226 get_initial_directory (new_path, PATH_MAX - 1);
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227 new_path += qxestrlen (new_path);
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446
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228 if (!IS_DIRECTORY_SEP (new_path[-1]))
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229 *new_path++ = DIRECTORY_SEP;
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428
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230 }
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231 else
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232 {
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446
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233 /* Copy first directory sep. May have two on cygwin. */
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771
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234 qxestrncpy (new_path, path, abslen);
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446
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235 new_path += abslen;
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236 path += abslen;
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428
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237 }
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238 #endif
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239 /* Expand each slash-separated pathname component. */
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240 while (*path != '\0')
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241 {
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242 /* Ignore stray "/". */
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446
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243 if (IS_DIRECTORY_SEP (*path))
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428
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244 {
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245 path++;
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246 continue;
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247 }
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248
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249 if (*path == '.')
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250 {
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251 /* Ignore ".". */
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446
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252 if (path[1] == '\0' || IS_DIRECTORY_SEP (path[1]))
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428
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253 {
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254 path++;
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255 continue;
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256 }
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257
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442
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258 /* Handle ".." */
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259 if (path[1] == '.' &&
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446
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260 (path[2] == '\0' || IS_DIRECTORY_SEP (path[2])))
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428
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261 {
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442
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262 path += 2;
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428
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263
|
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442
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264 /* Ignore ".." at root. */
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446
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265 if (new_path == ABS_START (resolved_path))
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442
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266 continue;
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428
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267
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442
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268 /* Handle ".." by backing up. */
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446
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269 --new_path;
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270 while (!IS_DIRECTORY_SEP (new_path[-1]))
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271 --new_path;
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442
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272 continue;
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428
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273 }
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274 }
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275
|
|
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276 /* Safely copy the next pathname component. */
|
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446
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277 while (*path != '\0' && !IS_DIRECTORY_SEP (*path))
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428
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278 {
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279 if (path > max_path)
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280 {
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281 errno = ENAMETOOLONG;
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282 return NULL;
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283 }
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284 *new_path++ = *path++;
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285 }
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286
|
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771
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287 #if defined (HAVE_READLINK) || defined (WIN32_NATIVE)
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|
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288 /* See if latest pathname component is a symlink or needs case
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289 correction. */
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428
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290 *new_path = '\0';
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771
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291 n = readlink_and_correct_case (resolved_path, link_path, PATH_MAX - 1);
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|
428
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292
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293 if (n < 0)
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294 {
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771
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295 /* EINVAL means the file exists but isn't a symlink or doesn't
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296 need case correction. */
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462
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297 #ifdef CYGWIN
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298 if (errno != EINVAL && errno != ENOENT)
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299 #else
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300 if (errno != EINVAL)
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|
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301 #endif
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428
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302 return NULL;
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303 }
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304 else
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305 {
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306 /* Protect against infinite loops. */
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307 if (readlinks++ > MAX_READLINKS)
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308 {
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309 errno = ELOOP;
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310 return NULL;
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311 }
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312
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|
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313 /* Note: readlink doesn't add the null byte. */
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314 link_path[n] = '\0';
|
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446
|
315
|
|
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316 if (ABS_LENGTH (link_path) > 0)
|
|
428
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317 /* Start over for an absolute symlink. */
|
|
446
|
318 new_path = resolved_path + ABS_LENGTH (link_path) - 1;
|
|
428
|
319 else
|
|
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320 /* Otherwise back up over this component. */
|
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446
|
321 for (--new_path; !IS_DIRECTORY_SEP (*new_path); --new_path)
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|
|
322 assert (new_path > resolved_path);
|
|
428
|
323
|
|
|
324 /* Safe sex check. */
|
|
771
|
325 if (qxestrlen (path) + n >= PATH_MAX)
|
|
428
|
326 {
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|
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327 errno = ENAMETOOLONG;
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|
|
328 return NULL;
|
|
|
329 }
|
|
|
330
|
|
|
331 /* Insert symlink contents into path. */
|
|
771
|
332 qxestrcat (link_path, path);
|
|
|
333 qxestrcpy (copy_path, link_path);
|
|
428
|
334 path = copy_path;
|
|
|
335 }
|
|
771
|
336 #endif /* HAVE_READLINK || WIN32_NATIVE */
|
|
446
|
337 *new_path++ = DIRECTORY_SEP;
|
|
428
|
338 }
|
|
|
339
|
|
|
340 /* Delete trailing slash but don't whomp a lone slash. */
|
|
771
|
341 if (new_path != ABS_START (resolved_path) &&
|
|
|
342 IS_DIRECTORY_SEP (new_path[-1]))
|
|
428
|
343 new_path--;
|
|
|
344
|
|
|
345 /* Make sure it's null terminated. */
|
|
|
346 *new_path = '\0';
|
|
446
|
347
|
|
428
|
348 return resolved_path;
|
|
|
349 }
|
