1 | /* |
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2 | * Copyright (c) 1990, 2007 The Regents of the University of California. |
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3 | * All rights reserved. |
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4 | * |
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5 | * Redistribution and use in source and binary forms are permitted |
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6 | * provided that the above copyright notice and this paragraph are |
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7 | * duplicated in all such forms and that any documentation, |
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8 | * advertising materials, and other materials related to such |
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9 | * distribution and use acknowledge that the software was developed |
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10 | * by the University of California, Berkeley. The name of the |
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11 | * University may not be used to endorse or promote products derived |
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12 | * from this software without specific prior written permission. |
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13 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
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14 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
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15 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
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16 | */ |
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17 | |
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18 | /* |
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19 | FUNCTION |
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20 | <<fread>>, <<fread_unlocked>>---read array elements from a file |
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21 | |
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22 | INDEX |
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23 | fread |
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24 | INDEX |
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25 | fread_unlocked |
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26 | INDEX |
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27 | _fread_r |
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28 | INDEX |
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29 | _fread_unlocked_r |
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30 | |
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31 | SYNOPSIS |
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32 | #include <stdio.h> |
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33 | size_t fread(void *restrict <[buf]>, size_t <[size]>, size_t <[count]>, |
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34 | FILE *restrict <[fp]>); |
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35 | |
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36 | #define _BSD_SOURCE |
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37 | #include <stdio.h> |
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38 | size_t fread_unlocked(void *restrict <[buf]>, size_t <[size]>, size_t <[count]>, |
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39 | FILE *restrict <[fp]>); |
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40 | |
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41 | #include <stdio.h> |
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42 | size_t _fread_r(struct _reent *<[ptr]>, void *restrict <[buf]>, |
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43 | size_t <[size]>, size_t <[count]>, FILE *restrict <[fp]>); |
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44 | |
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45 | #include <stdio.h> |
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46 | size_t _fread_unlocked_r(struct _reent *<[ptr]>, void *restrict <[buf]>, |
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47 | size_t <[size]>, size_t <[count]>, FILE *restrict <[fp]>); |
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48 | |
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49 | DESCRIPTION |
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50 | <<fread>> attempts to copy, from the file or stream identified by |
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51 | <[fp]>, <[count]> elements (each of size <[size]>) into memory, |
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52 | starting at <[buf]>. <<fread>> may copy fewer elements than |
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53 | <[count]> if an error, or end of file, intervenes. |
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54 | |
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55 | <<fread>> also advances the file position indicator (if any) for |
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56 | <[fp]> by the number of @emph{characters} actually read. |
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57 | |
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58 | <<fread_unlocked>> is a non-thread-safe version of <<fread>>. |
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59 | <<fread_unlocked>> may only safely be used within a scope |
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60 | protected by flockfile() (or ftrylockfile()) and funlockfile(). This |
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61 | function may safely be used in a multi-threaded program if and only |
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62 | if they are called while the invoking thread owns the (FILE *) |
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63 | object, as is the case after a successful call to the flockfile() or |
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64 | ftrylockfile() functions. If threads are disabled, then |
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65 | <<fread_unlocked>> is equivalent to <<fread>>. |
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66 | |
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67 | <<_fread_r>> and <<_fread_unlocked_r>> are simply reentrant versions of the |
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68 | above that take an additional reentrant structure pointer argument: <[ptr]>. |
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69 | |
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70 | RETURNS |
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71 | The result of <<fread>> is the number of elements it succeeded in |
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72 | reading. |
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73 | |
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74 | PORTABILITY |
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75 | ANSI C requires <<fread>>. |
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76 | |
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77 | <<fread_unlocked>> is a BSD extension also provided by GNU libc. |
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78 | |
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79 | Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>, |
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80 | <<lseek>>, <<read>>, <<sbrk>>, <<write>>. |
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81 | */ |
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82 | |
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83 | #include <_ansi.h> |
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84 | #include <stdio.h> |
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85 | #include <string.h> |
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86 | #include <malloc.h> |
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87 | #include "local.h" |
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88 | |
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89 | #ifdef __IMPL_UNLOCKED__ |
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90 | #define _fread_r _fread_unlocked_r |
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91 | #define fread fread_unlocked |
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92 | #endif |
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93 | |
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94 | #ifdef __SCLE |
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95 | static size_t |
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96 | crlf_r (struct _reent * ptr, |
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97 | FILE * fp, |
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98 | char * buf, |
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99 | size_t count, |
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100 | int eof) |
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101 | { |
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102 | int r; |
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103 | char *s, *d, *e; |
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104 | |
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105 | if (count == 0) |
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106 | return 0; |
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107 | |
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108 | e = buf + count; |
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109 | for (s=d=buf; s<e-1; s++) |
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110 | { |
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111 | if (*s == '\r' && s[1] == '\n') |
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112 | s++; |
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113 | *d++ = *s; |
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114 | } |
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115 | if (s < e) |
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116 | { |
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117 | if (*s == '\r') |
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118 | { |
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119 | int c = __sgetc_raw_r (ptr, fp); |
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120 | if (c == '\n') |
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121 | *s = '\n'; |
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122 | else |
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123 | ungetc (c, fp); |
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124 | } |
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125 | *d++ = *s++; |
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126 | } |
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127 | |
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128 | |
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129 | while (d < e) |
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130 | { |
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131 | r = _getc_r (ptr, fp); |
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132 | if (r == EOF) |
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133 | return count - (e-d); |
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134 | *d++ = r; |
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135 | } |
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136 | |
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137 | return count; |
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138 | |
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139 | } |
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140 | |
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141 | #endif |
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142 | |
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143 | size_t |
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144 | _fread_r (struct _reent * ptr, |
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145 | void *__restrict buf, |
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146 | size_t size, |
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147 | size_t count, |
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148 | FILE * __restrict fp) |
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149 | { |
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150 | register size_t resid; |
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151 | register char *p; |
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152 | register int r; |
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153 | size_t total; |
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154 | |
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155 | if ((resid = count * size) == 0) |
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156 | return 0; |
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157 | |
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158 | CHECK_INIT(ptr, fp); |
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159 | |
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160 | _newlib_flockfile_start (fp); |
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161 | ORIENT (fp, -1); |
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162 | if (fp->_r < 0) |
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163 | fp->_r = 0; |
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164 | total = resid; |
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165 | p = buf; |
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166 | |
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167 | #if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__) |
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168 | |
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169 | /* Optimize unbuffered I/O. */ |
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170 | if (fp->_flags & __SNBF) |
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171 | { |
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172 | /* First copy any available characters from ungetc buffer. */ |
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173 | int copy_size = resid > fp->_r ? fp->_r : resid; |
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174 | (void) memcpy ((void *) p, (void *) fp->_p, (size_t) copy_size); |
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175 | fp->_p += copy_size; |
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176 | fp->_r -= copy_size; |
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177 | p += copy_size; |
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178 | resid -= copy_size; |
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179 | |
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180 | /* If still more data needed, free any allocated ungetc buffer. */ |
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181 | if (HASUB (fp) && resid > 0) |
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182 | FREEUB (ptr, fp); |
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183 | |
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184 | /* Finally read directly into user's buffer if needed. */ |
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185 | while (resid > 0) |
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186 | { |
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187 | int rc = 0; |
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188 | /* save fp buffering state */ |
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189 | void *old_base = fp->_bf._base; |
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190 | void * old_p = fp->_p; |
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191 | int old_size = fp->_bf._size; |
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192 | /* allow __refill to use user's buffer */ |
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193 | fp->_bf._base = (unsigned char *) p; |
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194 | fp->_bf._size = resid; |
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195 | fp->_p = (unsigned char *) p; |
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196 | rc = __srefill_r (ptr, fp); |
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197 | /* restore fp buffering back to original state */ |
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198 | fp->_bf._base = old_base; |
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199 | fp->_bf._size = old_size; |
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200 | fp->_p = old_p; |
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201 | resid -= fp->_r; |
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202 | p += fp->_r; |
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203 | fp->_r = 0; |
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204 | if (rc) |
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205 | { |
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206 | #ifdef __SCLE |
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207 | if (fp->_flags & __SCLE) |
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208 | { |
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209 | _newlib_flockfile_exit (fp); |
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210 | return crlf_r (ptr, fp, buf, total-resid, 1) / size; |
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211 | } |
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212 | #endif |
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213 | _newlib_flockfile_exit (fp); |
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214 | return (total - resid) / size; |
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215 | } |
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216 | } |
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217 | } |
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218 | else |
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219 | #endif /* !PREFER_SIZE_OVER_SPEED && !__OPTIMIZE_SIZE__ */ |
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220 | { |
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221 | while (resid > (r = fp->_r)) |
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222 | { |
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223 | (void) memcpy ((void *) p, (void *) fp->_p, (size_t) r); |
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224 | fp->_p += r; |
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225 | /* fp->_r = 0 ... done in __srefill */ |
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226 | p += r; |
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227 | resid -= r; |
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228 | if (__srefill_r (ptr, fp)) |
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229 | { |
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230 | /* no more input: return partial result */ |
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231 | #ifdef __SCLE |
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232 | if (fp->_flags & __SCLE) |
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233 | { |
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234 | _newlib_flockfile_exit (fp); |
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235 | return crlf_r (ptr, fp, buf, total-resid, 1) / size; |
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236 | } |
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237 | #endif |
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238 | _newlib_flockfile_exit (fp); |
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239 | return (total - resid) / size; |
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240 | } |
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241 | } |
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242 | (void) memcpy ((void *) p, (void *) fp->_p, resid); |
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243 | fp->_r -= resid; |
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244 | fp->_p += resid; |
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245 | } |
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246 | |
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247 | /* Perform any CR/LF clean-up if necessary. */ |
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248 | #ifdef __SCLE |
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249 | if (fp->_flags & __SCLE) |
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250 | { |
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251 | _newlib_flockfile_exit (fp); |
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252 | return crlf_r(ptr, fp, buf, total, 0) / size; |
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253 | } |
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254 | #endif |
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255 | _newlib_flockfile_end (fp); |
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256 | return count; |
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257 | } |
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258 | |
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259 | #ifndef _REENT_ONLY |
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260 | size_t |
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261 | fread (void *__restrict buf, |
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262 | size_t size, |
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263 | size_t count, |
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264 | FILE *__restrict fp) |
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265 | { |
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266 | return _fread_r (_REENT, buf, size, count, fp); |
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267 | } |
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268 | #endif |
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