1 | /*- |
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2 | * Copyright (c) 1991, 1993, 1994 |
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3 | * The Regents of the University of California. All rights reserved. |
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4 | * |
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5 | * This code is derived from software contributed to Berkeley by |
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6 | * Keith Muller of the University of California, San Diego and Lance |
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7 | * Visser of Convex Computer Corporation. |
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8 | * |
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9 | * Redistribution and use in source and binary forms, with or without |
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10 | * modification, are permitted provided that the following conditions |
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11 | * are met: |
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12 | * 1. Redistributions of source code must retain the above copyright |
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13 | * notice, this list of conditions and the following disclaimer. |
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14 | * 2. Redistributions in binary form must reproduce the above copyright |
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15 | * notice, this list of conditions and the following disclaimer in the |
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16 | * documentation and/or other materials provided with the distribution. |
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17 | * 4. Neither the name of the University nor the names of its contributors |
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18 | * may be used to endorse or promote products derived from this software |
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19 | * without specific prior written permission. |
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20 | * |
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21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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31 | * SUCH DAMAGE. |
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32 | */ |
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33 | |
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34 | #ifndef lint |
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35 | #if 0 |
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36 | static char sccsid[] = "@(#)position.c 8.3 (Berkeley) 4/2/94"; |
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37 | #include <sys/cdefs.h> |
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38 | __FBSDID("$FreeBSD: src/bin/dd/position.c,v 1.23 2004/04/06 20:06:46 markm Exp $"); |
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39 | #endif |
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40 | #endif /* not lint */ |
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41 | |
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42 | #include <sys/types.h> |
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43 | #if RTEMS_REMOVED |
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44 | #include <sys/mtio.h> |
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45 | #endif |
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46 | |
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47 | #include <err.h> |
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48 | #include <errno.h> |
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49 | #include <inttypes.h> |
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50 | #include <unistd.h> |
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51 | |
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52 | #include "dd.h" |
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53 | #include "extern-dd.h" |
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54 | |
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55 | /* |
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56 | * Position input/output data streams before starting the copy. Device type |
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57 | * dependent. Seekable devices use lseek, and the rest position by reading. |
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58 | * Seeking past the end of file can cause null blocks to be written to the |
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59 | * output. |
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60 | */ |
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61 | void |
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62 | pos_in(rtems_shell_dd_globals* globals) |
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63 | { |
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64 | off_t cnt; |
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65 | int warned; |
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66 | ssize_t nr; |
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67 | size_t bcnt; |
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68 | |
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69 | /* If known to be seekable, try to seek on it. */ |
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70 | if (in.flags & ISSEEK) { |
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71 | errno = 0; |
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72 | if (lseek(in.fd, in.offset * in.dbsz, SEEK_CUR) == -1 && |
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73 | errno != 0) |
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74 | err(exit_jump, 1, "%s", in.name); |
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75 | return; |
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76 | } |
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77 | |
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78 | /* Don't try to read a really weird amount (like negative). */ |
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79 | if (in.offset < 0) |
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80 | errx(exit_jump, 1, "%s: illegal offset", "iseek/skip"); |
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81 | |
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82 | /* |
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83 | * Read the data. If a pipe, read until satisfy the number of bytes |
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84 | * being skipped. No differentiation for reading complete and partial |
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85 | * blocks for other devices. |
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86 | */ |
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87 | for (bcnt = in.dbsz, cnt = in.offset, warned = 0; cnt;) { |
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88 | if ((nr = read(in.fd, in.db, bcnt)) > 0) { |
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89 | if (in.flags & ISPIPE) { |
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90 | if (!(bcnt -= nr)) { |
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91 | bcnt = in.dbsz; |
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92 | --cnt; |
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93 | } |
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94 | } else |
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95 | --cnt; |
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96 | continue; |
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97 | } |
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98 | |
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99 | if (nr == 0) { |
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100 | if (files_cnt > 1) { |
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101 | --files_cnt; |
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102 | continue; |
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103 | } |
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104 | errx(exit_jump, 1, "skip reached end of input"); |
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105 | } |
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106 | |
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107 | /* |
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108 | * Input error -- either EOF with no more files, or I/O error. |
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109 | * If noerror not set die. POSIX requires that the warning |
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110 | * message be followed by an I/O display. |
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111 | */ |
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112 | if (ddflags & C_NOERROR) { |
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113 | if (!warned) { |
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114 | warn("%s", in.name); |
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115 | warned = 1; |
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116 | summary(globals); |
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117 | } |
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118 | continue; |
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119 | } |
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120 | err(exit_jump, 1, "%s", in.name); |
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121 | } |
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122 | } |
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123 | |
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124 | void |
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125 | pos_out(rtems_shell_dd_globals* globals) |
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126 | { |
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127 | #if RTEMS_REMOVED |
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128 | struct mtop t_op; |
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129 | off_t cnt; |
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130 | ssize_t n; |
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131 | #endif |
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132 | |
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133 | /* |
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134 | * If not a tape, try seeking on the file. Seeking on a pipe is |
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135 | * going to fail, but don't protect the user -- they shouldn't |
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136 | * have specified the seek operand. |
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137 | */ |
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138 | if (out.flags & (ISSEEK | ISPIPE)) { |
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139 | errno = 0; |
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140 | if (lseek(out.fd, out.offset * out.dbsz, SEEK_CUR) == -1 && |
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141 | errno != 0) |
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142 | err(exit_jump, 1, "%s", out.name); |
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143 | return; |
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144 | } |
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145 | |
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146 | /* Don't try to read a really weird amount (like negative). */ |
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147 | if (out.offset < 0) |
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148 | errx(exit_jump, 1, "%s: illegal offset", "oseek/seek"); |
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149 | |
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150 | #if RTEMS_REMOVED |
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151 | /* If no read access, try using mtio. */ |
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152 | if (out.flags & NOREAD) { |
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153 | t_op.mt_op = MTFSR; |
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154 | t_op.mt_count = out.offset; |
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155 | |
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156 | if (ioctl(out.fd, MTIOCTOP, &t_op) == -1) |
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157 | err(1, "%s", out.name); |
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158 | return; |
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159 | } |
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160 | |
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161 | /* Read it. */ |
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162 | for (cnt = 0; cnt < out.offset; ++cnt) { |
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163 | if ((n = read(out.fd, out.db, out.dbsz)) > 0) |
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164 | continue; |
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165 | |
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166 | if (n == -1) |
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167 | err(1, "%s", out.name); |
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168 | |
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169 | /* |
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170 | * If reach EOF, fill with NUL characters; first, back up over |
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171 | * the EOF mark. Note, cnt has not yet been incremented, so |
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172 | * the EOF read does not count as a seek'd block. |
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173 | */ |
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174 | t_op.mt_op = MTBSR; |
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175 | t_op.mt_count = 1; |
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176 | if (ioctl(out.fd, MTIOCTOP, &t_op) == -1) |
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177 | err(1, "%s", out.name); |
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178 | |
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179 | while (cnt++ < out.offset) { |
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180 | n = write(out.fd, out.db, out.dbsz); |
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181 | if (n == -1) |
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182 | err(1, "%s", out.name); |
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183 | if ((size_t)n != out.dbsz) |
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184 | errx(1, "%s: write failure", out.name); |
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185 | } |
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186 | break; |
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187 | } |
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188 | #endif |
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189 | } |
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