1 | /* |
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2 | * Copyright (c) 1990 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 | <<fwrite>>, <<fwrite_unlocked>>---write array elements |
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21 | |
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22 | INDEX |
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23 | fwrite |
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24 | INDEX |
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25 | fwrite_unlocked |
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26 | INDEX |
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27 | _fwrite_r |
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28 | INDEX |
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29 | _fwrite_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 fwrite(const void *restrict <[buf]>, size_t <[size]>, |
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34 | size_t <[count]>, 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 fwrite_unlocked(const void *restrict <[buf]>, size_t <[size]>, |
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39 | size_t <[count]>, FILE *restrict <[fp]>); |
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40 | |
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41 | #include <stdio.h> |
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42 | size_t _fwrite_r(struct _reent *<[ptr]>, const void *restrict <[buf]>, size_t <[size]>, |
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43 | 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 _fwrite_unlocked_r(struct _reent *<[ptr]>, const void *restrict <[buf]>, size_t <[size]>, |
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47 | size_t <[count]>, FILE *restrict <[fp]>); |
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48 | |
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49 | DESCRIPTION |
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50 | <<fwrite>> attempts to copy, starting from the memory location |
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51 | <[buf]>, <[count]> elements (each of size <[size]>) into the file or |
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52 | stream identified by <[fp]>. <<fwrite>> may copy fewer elements than |
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53 | <[count]> if an error intervenes. |
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54 | |
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55 | <<fwrite>> also advances the file position indicator (if any) for |
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56 | <[fp]> by the number of @emph{characters} actually written. |
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57 | |
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58 | <<fwrite_unlocked>> is a non-thread-safe version of <<fwrite>>. |
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59 | <<fwrite_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 | <<fwrite_unlocked>> is equivalent to <<fwrite>>. |
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66 | |
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67 | <<_fwrite_r>> and <<_fwrite_unlocked_r>> are simply reentrant versions of the |
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68 | above that take an additional reentrant structure argument: <[ptr]>. |
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69 | |
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70 | RETURNS |
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71 | If <<fwrite>> succeeds in writing all the elements you specify, the |
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72 | result is the same as the argument <[count]>. In any event, the |
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73 | result is the number of complete elements that <<fwrite>> copied to |
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74 | the file. |
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75 | |
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76 | PORTABILITY |
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77 | ANSI C requires <<fwrite>>. |
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78 | |
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79 | <<fwrite_unlocked>> is a BSD extension also provided by GNU libc. |
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80 | |
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81 | Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>, |
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82 | <<lseek>>, <<read>>, <<sbrk>>, <<write>>. |
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83 | */ |
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84 | |
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85 | #if defined(LIBC_SCCS) && !defined(lint) |
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86 | static char sccsid[] = "%W% (Berkeley) %G%"; |
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87 | #endif /* LIBC_SCCS and not lint */ |
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88 | |
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89 | #include <_ansi.h> |
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90 | #include <stdio.h> |
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91 | #include <string.h> |
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92 | #if 0 |
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93 | #include <sys/stdc.h> |
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94 | #endif |
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95 | #include "local.h" |
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96 | #if 1 |
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97 | #include "fvwrite.h" |
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98 | #endif |
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99 | |
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100 | #ifdef __IMPL_UNLOCKED__ |
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101 | #define _fwrite_r _fwrite_unlocked_r |
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102 | #define fwrite fwrite_unlocked |
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103 | #endif |
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104 | |
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105 | /* |
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106 | * Write `count' objects (each size `size') from memory to the given file. |
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107 | * Return the number of whole objects written. |
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108 | */ |
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109 | |
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110 | size_t |
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111 | _fwrite_r (struct _reent * ptr, |
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112 | const void *__restrict buf, |
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113 | size_t size, |
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114 | size_t count, |
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115 | FILE * __restrict fp) |
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116 | { |
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117 | size_t n; |
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118 | #ifdef _FVWRITE_IN_STREAMIO |
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119 | struct __suio uio; |
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120 | struct __siov iov; |
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121 | |
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122 | iov.iov_base = buf; |
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123 | uio.uio_resid = iov.iov_len = n = count * size; |
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124 | uio.uio_iov = &iov; |
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125 | uio.uio_iovcnt = 1; |
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126 | |
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127 | /* |
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128 | * The usual case is success (__sfvwrite_r returns 0); |
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129 | * skip the divide if this happens, since divides are |
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130 | * generally slow and since this occurs whenever size==0. |
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131 | */ |
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132 | |
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133 | CHECK_INIT(ptr, fp); |
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134 | |
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135 | _newlib_flockfile_start (fp); |
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136 | ORIENT (fp, -1); |
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137 | if (__sfvwrite_r (ptr, fp, &uio) == 0) |
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138 | { |
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139 | _newlib_flockfile_exit (fp); |
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140 | return count; |
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141 | } |
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142 | _newlib_flockfile_end (fp); |
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143 | return (n - uio.uio_resid) / size; |
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144 | #else |
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145 | size_t i = 0; |
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146 | const char *p = buf; |
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147 | n = count * size; |
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148 | CHECK_INIT (ptr, fp); |
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149 | |
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150 | _newlib_flockfile_start (fp); |
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151 | ORIENT (fp, -1); |
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152 | /* Make sure we can write. */ |
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153 | if (cantwrite (ptr, fp)) |
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154 | goto ret; |
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155 | |
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156 | while (i < n) |
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157 | { |
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158 | if (__sputc_r (ptr, p[i], fp) == EOF) |
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159 | break; |
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160 | |
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161 | i++; |
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162 | } |
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163 | |
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164 | ret: |
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165 | _newlib_flockfile_end (fp); |
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166 | return i / size; |
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167 | #endif |
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168 | } |
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169 | |
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170 | #ifndef _REENT_ONLY |
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171 | size_t |
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172 | fwrite (const void *__restrict buf, |
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173 | size_t size, |
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174 | size_t count, |
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175 | FILE * fp) |
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176 | { |
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177 | return _fwrite_r (_REENT, buf, size, count, fp); |
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178 | } |
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179 | #endif |
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