1 | /* $NetBSD: fvwrite.c,v 1.17 2007/02/02 23:00:28 christos Exp $ */ |
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2 | |
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3 | /*- |
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4 | * Copyright (c) 1990, 1993 |
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5 | * The Regents of the University of California. All rights reserved. |
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6 | * |
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7 | * This code is derived from software contributed to Berkeley by |
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8 | * Chris Torek. |
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9 | * |
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10 | * Redistribution and use in source and binary forms, with or without |
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11 | * modification, are permitted provided that the following conditions |
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12 | * are met: |
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13 | * 1. Redistributions of source code must retain the above copyright |
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14 | * notice, this list of conditions and the following disclaimer. |
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15 | * 2. Redistributions in binary form must reproduce the above copyright |
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16 | * notice, this list of conditions and the following disclaimer in the |
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17 | * documentation and/or other materials provided with the distribution. |
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18 | * 3. Neither the name of the University nor the names of its contributors |
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19 | * may be used to endorse or promote products derived from this software |
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20 | * without specific prior written permission. |
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21 | * |
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22 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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23 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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24 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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25 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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26 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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27 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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28 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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29 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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30 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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31 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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32 | * SUCH DAMAGE. |
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33 | */ |
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34 | |
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35 | #include <sys/cdefs.h> |
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36 | #if defined(LIBC_SCCS) && !defined(lint) |
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37 | #if 0 |
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38 | static char sccsid[] = "@(#)fvwrite.c 8.1 (Berkeley) 6/4/93"; |
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39 | #else |
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40 | __RCSID("$NetBSD: fvwrite.c,v 1.17 2007/02/02 23:00:28 christos Exp $"); |
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41 | #endif |
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42 | #endif /* LIBC_SCCS and not lint */ |
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43 | |
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44 | #include <assert.h> |
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45 | #include <errno.h> |
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46 | #include <stdio.h> |
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47 | #include <stdlib.h> |
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48 | #include <string.h> |
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49 | #include "reentrant.h" |
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50 | #include "local.h" |
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51 | #include "fvwrite.h" |
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52 | |
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53 | /* |
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54 | * Write some memory regions. Return zero on success, EOF on error. |
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55 | * |
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56 | * This routine is large and unsightly, but most of the ugliness due |
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57 | * to the three different kinds of output buffering is handled here. |
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58 | */ |
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59 | int |
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60 | __sfvwrite(fp, uio) |
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61 | FILE *fp; |
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62 | struct __suio *uio; |
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63 | { |
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64 | size_t len; |
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65 | char *p; |
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66 | struct __siov *iov; |
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67 | int w, s; |
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68 | char *nl; |
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69 | int nlknown, nldist; |
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70 | |
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71 | _DIAGASSERT(fp != NULL); |
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72 | _DIAGASSERT(uio != NULL); |
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73 | |
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74 | if ((len = uio->uio_resid) == 0) |
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75 | return (0); |
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76 | /* make sure we can write */ |
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77 | if (cantwrite(fp)) { |
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78 | errno = EBADF; |
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79 | return (EOF); |
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80 | } |
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81 | |
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82 | #define MIN(a, b) ((a) < (b) ? (a) : (b)) |
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83 | #define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n)) |
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84 | |
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85 | iov = uio->uio_iov; |
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86 | p = iov->iov_base; |
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87 | len = iov->iov_len; |
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88 | iov++; |
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89 | #define GETIOV(extra_work) \ |
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90 | while (len == 0) { \ |
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91 | extra_work; \ |
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92 | p = iov->iov_base; \ |
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93 | len = iov->iov_len; \ |
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94 | iov++; \ |
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95 | } |
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96 | if (fp->_flags & __SNBF) { |
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97 | /* |
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98 | * Unbuffered: write up to BUFSIZ bytes at a time. |
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99 | */ |
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100 | do { |
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101 | GETIOV(;); |
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102 | w = (*fp->_write)(fp->_cookie, p, |
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103 | (int)MIN(len, BUFSIZ)); |
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104 | if (w <= 0) |
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105 | goto err; |
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106 | p += w; |
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107 | len -= w; |
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108 | } while ((uio->uio_resid -= w) != 0); |
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109 | } else if ((fp->_flags & __SLBF) == 0) { |
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110 | /* |
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111 | * Fully buffered: fill partially full buffer, if any, |
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112 | * and then flush. If there is no partial buffer, write |
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113 | * one _bf._size byte chunk directly (without copying). |
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114 | * |
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115 | * String output is a special case: write as many bytes |
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116 | * as fit, but pretend we wrote everything. This makes |
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117 | * snprintf() return the number of bytes needed, rather |
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118 | * than the number used, and avoids its write function |
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119 | * (so that the write function can be invalid). |
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120 | */ |
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121 | do { |
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122 | GETIOV(;); |
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123 | if ((fp->_flags & (__SALC | __SSTR)) == |
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124 | (__SALC | __SSTR) && fp->_w < len) { |
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125 | size_t blen = fp->_p - fp->_bf._base; |
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126 | unsigned char *_base; |
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127 | int _size; |
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128 | |
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129 | /* Allocate space exponentially. */ |
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130 | _size = fp->_bf._size; |
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131 | do { |
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132 | _size = (_size << 1) + 1; |
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133 | } while (_size < blen + len); |
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134 | _base = realloc(fp->_bf._base, |
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135 | (size_t)(_size + 1)); |
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136 | if (_base == NULL) |
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137 | goto err; |
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138 | fp->_w += _size - fp->_bf._size; |
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139 | fp->_bf._base = _base; |
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140 | fp->_bf._size = _size; |
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141 | fp->_p = _base + blen; |
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142 | } |
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143 | w = fp->_w; |
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144 | if (fp->_flags & __SSTR) { |
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145 | if (len < w) |
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146 | w = len; |
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147 | COPY(w); /* copy MIN(fp->_w,len), */ |
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148 | fp->_w -= w; |
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149 | fp->_p += w; |
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150 | w = len; /* but pretend copied all */ |
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151 | } else if (fp->_p > fp->_bf._base && len > w) { |
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152 | /* fill and flush */ |
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153 | COPY(w); |
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154 | /* fp->_w -= w; */ /* unneeded */ |
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155 | fp->_p += w; |
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156 | if (fflush(fp)) |
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157 | goto err; |
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158 | } else if (len >= (w = fp->_bf._size)) { |
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159 | /* write directly */ |
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160 | w = (*fp->_write)(fp->_cookie, p, w); |
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161 | if (w <= 0) |
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162 | goto err; |
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163 | } else { |
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164 | /* fill and done */ |
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165 | w = len; |
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166 | COPY(w); |
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167 | fp->_w -= w; |
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168 | fp->_p += w; |
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169 | } |
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170 | p += w; |
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171 | len -= w; |
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172 | } while ((uio->uio_resid -= w) != 0); |
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173 | } else { |
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174 | /* |
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175 | * Line buffered: like fully buffered, but we |
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176 | * must check for newlines. Compute the distance |
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177 | * to the first newline (including the newline), |
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178 | * or `infinity' if there is none, then pretend |
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179 | * that the amount to write is MIN(len,nldist). |
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180 | */ |
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181 | nlknown = 0; |
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182 | nldist = 0; /* XXX just to keep gcc happy */ |
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183 | do { |
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184 | GETIOV(nlknown = 0); |
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185 | if (!nlknown) { |
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186 | nl = memchr((void *)p, '\n', len); |
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187 | nldist = nl ? nl + 1 - p : len + 1; |
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188 | nlknown = 1; |
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189 | } |
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190 | s = MIN(len, nldist); |
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191 | w = fp->_w + fp->_bf._size; |
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192 | if (fp->_p > fp->_bf._base && s > w) { |
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193 | COPY(w); |
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194 | /* fp->_w -= w; */ |
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195 | fp->_p += w; |
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196 | if (fflush(fp)) |
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197 | goto err; |
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198 | } else if (s >= (w = fp->_bf._size)) { |
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199 | w = (*fp->_write)(fp->_cookie, p, w); |
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200 | if (w <= 0) |
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201 | goto err; |
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202 | } else { |
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203 | w = s; |
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204 | COPY(w); |
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205 | fp->_w -= w; |
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206 | fp->_p += w; |
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207 | } |
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208 | if ((nldist -= w) == 0) { |
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209 | /* copied the newline: flush and forget */ |
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210 | if (fflush(fp)) |
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211 | goto err; |
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212 | nlknown = 0; |
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213 | } |
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214 | p += w; |
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215 | len -= w; |
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216 | } while ((uio->uio_resid -= w) != 0); |
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217 | } |
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218 | return (0); |
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219 | |
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220 | err: |
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221 | fp->_flags |= __SERR; |
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222 | return (EOF); |
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223 | } |
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