1 | /* Utilities for reading/writing fstab, mtab, etc. |
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2 | Copyright (C) 1995-2000, 2001 Free Software Foundation, Inc. |
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3 | This file is part of the GNU C Library. |
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4 | |
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5 | The GNU C Library is free software; you can redistribute it and/or |
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6 | modify it under the terms of the GNU Lesser General Public |
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7 | License as published by the Free Software Foundation; either |
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8 | version 2.1 of the License, or (at your option) any later version. |
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9 | |
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10 | The GNU C Library is distributed in the hope that it will be useful, |
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11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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13 | Lesser General Public License for more details. |
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14 | |
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15 | You should have received a copy of the GNU Lesser General Public |
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16 | License along with the GNU C Library; if not, write to the Free |
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17 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
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18 | 02111-1307 USA. */ |
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19 | |
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20 | #include <alloca.h> |
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21 | #include <mntent.h> |
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22 | #include <stdio.h> |
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23 | #include <string.h> |
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24 | #include <sys/types.h> |
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25 | #include <machine/weakalias.h> |
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26 | |
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27 | /* Prepare to begin reading and/or writing mount table entries from the |
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28 | beginning of FILE. MODE is as for `fopen'. */ |
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29 | FILE * |
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30 | __setmntent (const char *file, const char *mode) |
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31 | { |
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32 | FILE *result = fopen (file, mode); |
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33 | |
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34 | return result; |
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35 | } |
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36 | weak_alias (__setmntent, setmntent) |
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37 | |
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38 | |
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39 | /* Close a stream opened with `setmntent'. */ |
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40 | int |
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41 | __endmntent (FILE *stream) |
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42 | { |
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43 | if (stream) /* SunOS 4.x allows for NULL stream */ |
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44 | fclose (stream); |
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45 | return 1; /* SunOS 4.x says to always return 1 */ |
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46 | } |
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47 | weak_alias (__endmntent, endmntent) |
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48 | |
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49 | |
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50 | /* Since the values in a line are separated by spaces, a name cannot |
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51 | contain a space. Therefore some programs encode spaces in names |
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52 | by the strings "\040". We undo the encoding when reading an entry. |
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53 | The decoding happens in place. */ |
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54 | static char * |
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55 | decode_name (char *buf) |
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56 | { |
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57 | char *rp = buf; |
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58 | char *wp = buf; |
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59 | |
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60 | do |
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61 | if (rp[0] == '\\' && rp[1] == '0' && rp[2] == '4' && rp[3] == '0') |
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62 | { |
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63 | /* \040 is a SPACE. */ |
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64 | *wp++ = ' '; |
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65 | rp += 3; |
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66 | } |
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67 | else if (rp[0] == '\\' && rp[1] == '0' && rp[2] == '1' && rp[3] == '2') |
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68 | { |
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69 | /* \012 is a TAB. */ |
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70 | *wp++ = '\t'; |
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71 | rp += 3; |
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72 | } |
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73 | else if (rp[0] == '\\' && rp[1] == '\\') |
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74 | { |
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75 | /* We have to escape \\ to be able to represent all characters. */ |
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76 | *wp++ = '\\'; |
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77 | rp += 1; |
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78 | } |
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79 | else |
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80 | *wp++ = *rp; |
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81 | while (*rp++ != '\0'); |
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82 | |
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83 | return buf; |
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84 | } |
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85 | |
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86 | |
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87 | /* Read one mount table entry from STREAM. Returns a pointer to storage |
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88 | reused on the next call, or null for EOF or error (use feof/ferror to |
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89 | check). */ |
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90 | struct mntent * |
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91 | __getmntent_r (FILE *stream, struct mntent *mp, char *buffer, int bufsiz) |
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92 | { |
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93 | char *cp; |
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94 | char *head; |
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95 | |
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96 | flockfile (stream); |
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97 | do |
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98 | { |
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99 | char *end_ptr; |
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100 | |
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101 | if (fgets (buffer, bufsiz, stream) == NULL) |
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102 | { |
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103 | funlockfile (stream); |
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104 | return NULL; |
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105 | } |
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106 | |
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107 | end_ptr = strchr (buffer, '\n'); |
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108 | if (end_ptr != NULL) /* chop newline */ |
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109 | *end_ptr = '\0'; |
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110 | else |
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111 | { |
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112 | /* Not the whole line was read. Do it now but forget it. */ |
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113 | char tmp[1024]; |
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114 | while (fgets (tmp, sizeof tmp, stream) != NULL) |
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115 | if (strchr (tmp, '\n') != NULL) |
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116 | break; |
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117 | } |
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118 | |
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119 | head = buffer + strspn (buffer, " \t"); |
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120 | /* skip empty lines and comment lines: */ |
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121 | } |
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122 | while (head[0] == '\0' || head[0] == '#'); |
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123 | |
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124 | cp = strsep (&head, " \t"); |
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125 | mp->mnt_fsname = cp != NULL ? decode_name (cp) : (char *) ""; |
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126 | if (head) |
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127 | head += strspn (head, " \t"); |
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128 | cp = strsep (&head, " \t"); |
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129 | mp->mnt_dir = cp != NULL ? decode_name (cp) : (char *) ""; |
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130 | if (head) |
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131 | head += strspn (head, " \t"); |
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132 | cp = strsep (&head, " \t"); |
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133 | mp->mnt_type = cp != NULL ? decode_name (cp) : (char *) ""; |
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134 | if (head) |
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135 | head += strspn (head, " \t"); |
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136 | cp = strsep (&head, " \t"); |
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137 | mp->mnt_opts = cp != NULL ? decode_name (cp) : (char *) ""; |
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138 | switch (head ? sscanf (head, " %d %d ", &mp->mnt_freq, &mp->mnt_passno) : 0) |
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139 | { |
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140 | case 0: |
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141 | mp->mnt_freq = 0; |
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142 | case 1: |
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143 | mp->mnt_passno = 0; |
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144 | case 2: |
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145 | break; |
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146 | } |
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147 | funlockfile (stream); |
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148 | |
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149 | return mp; |
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150 | } |
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151 | weak_alias (__getmntent_r, getmntent_r) |
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152 | |
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153 | |
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154 | /* We have to use an encoding for names if they contain spaces or tabs. |
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155 | To be able to represent all characters we also have to escape the |
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156 | backslash itself. This "function" must be a macro since we use |
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157 | `alloca'. */ |
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158 | #define encode_name(name) \ |
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159 | do { \ |
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160 | const char *rp = name; \ |
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161 | \ |
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162 | while (*rp != '\0') \ |
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163 | if (*rp == ' ' || *rp == '\t' || *rp == '\\') \ |
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164 | break; \ |
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165 | else \ |
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166 | ++rp; \ |
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167 | \ |
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168 | if (*rp != '\0') \ |
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169 | { \ |
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170 | /* In the worst case the length of the string can increase to \ |
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171 | founr times the current length. */ \ |
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172 | char *wp; \ |
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173 | \ |
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174 | rp = name; \ |
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175 | name = wp = (char *) alloca (strlen (name) * 4 + 1); \ |
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176 | \ |
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177 | do \ |
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178 | if (*rp == ' ') \ |
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179 | { \ |
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180 | *wp++ = '\\'; \ |
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181 | *wp++ = '0'; \ |
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182 | *wp++ = '4'; \ |
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183 | *wp++ = '0'; \ |
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184 | } \ |
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185 | else if (*rp == '\t') \ |
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186 | { \ |
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187 | *wp++ = '\\'; \ |
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188 | *wp++ = '0'; \ |
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189 | *wp++ = '1'; \ |
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190 | *wp++ = '2'; \ |
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191 | } \ |
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192 | else if (*rp == '\\') \ |
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193 | { \ |
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194 | *wp++ = '\\'; \ |
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195 | *wp++ = '\\'; \ |
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196 | } \ |
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197 | else \ |
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198 | *wp++ = *rp; \ |
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199 | while (*rp++ != '\0'); \ |
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200 | } \ |
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201 | } while (0) |
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202 | |
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203 | |
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204 | /* Write the mount table entry described by MNT to STREAM. |
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205 | Return zero on success, nonzero on failure. */ |
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206 | int |
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207 | __addmntent (FILE *stream, const struct mntent *mnt) |
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208 | { |
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209 | struct mntent mntcopy = *mnt; |
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210 | if (fseek (stream, 0, SEEK_END)) |
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211 | return 1; |
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212 | |
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213 | /* Encode spaces and tabs in the names. */ |
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214 | encode_name (mntcopy.mnt_fsname); |
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215 | encode_name (mntcopy.mnt_dir); |
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216 | encode_name (mntcopy.mnt_type); |
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217 | encode_name (mntcopy.mnt_opts); |
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218 | |
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219 | return (fprintf (stream, "%s %s %s %s %d %d\n", |
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220 | mntcopy.mnt_fsname, |
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221 | mntcopy.mnt_dir, |
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222 | mntcopy.mnt_type, |
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223 | mntcopy.mnt_opts, |
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224 | mntcopy.mnt_freq, |
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225 | mntcopy.mnt_passno) |
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226 | < 0 ? 1 : 0); |
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227 | } |
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228 | weak_alias (__addmntent, addmntent) |
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229 | |
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230 | |
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231 | /* Search MNT->mnt_opts for an option matching OPT. |
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232 | Returns the address of the substring, or null if none found. */ |
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233 | char * |
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234 | __hasmntopt (const struct mntent *mnt, const char *opt) |
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235 | { |
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236 | const size_t optlen = strlen (opt); |
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237 | char *rest = mnt->mnt_opts, *p; |
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238 | |
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239 | while ((p = strstr (rest, opt)) != NULL) |
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240 | { |
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241 | if (p == rest |
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242 | || (p[-1] == ',' |
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243 | && (p[optlen] == '\0' || |
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244 | p[optlen] == '=' || |
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245 | p[optlen] == ','))) |
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246 | return p; |
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247 | |
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248 | rest = strchr (rest, ','); |
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249 | if (rest == NULL) |
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250 | break; |
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251 | ++rest; |
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252 | } |
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253 | |
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254 | return NULL; |
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255 | } |
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256 | weak_alias (__hasmntopt, hasmntopt) |
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