dd.1 (3346B)
1 .TH DD 1 2 .SH NAME 3 dd \- convert and copy a file 4 .SH SYNOPSIS 5 .B dd 6 [ 7 .I option value 8 ] 9 \&... 10 .SH DESCRIPTION 11 .I Dd\^ 12 copies the specified input file 13 to the specified output with 14 possible conversions. 15 The standard input and output are used by default. 16 The input and output block size may be 17 specified to take advantage of raw physical I/O. 18 The options are 19 .TF "quiet\ \ \fIn 20 .PD 21 .TP 22 .BI -if\ f 23 Open file 24 .I f 25 for input. 26 .TP 27 .BI -of\ f 28 Open file 29 .I f 30 for output. 31 .TP 32 .BI -ibs\ n\^ 33 Set input block size to 34 .I n\^ 35 bytes (default 512). 36 .TP 37 .BI -obs\ n\^ 38 Set output block size (default 512). 39 .TP 40 .BI -bs\ n\^ 41 Set both input and output block size, 42 superseding 43 .I ibs\^ 44 and 45 .IR obs . 46 If no conversion is specified, 47 preserve the input block size instead of packing short blocks 48 into the output buffer. 49 This is particularly efficient since no in-core copy need be done. 50 .TP 51 .BI -cbs\ n\^ 52 Set conversion buffer size. 53 .TP 54 .BI -skip\ n\^ 55 Skip 56 .I n 57 input records before copying. 58 .TP 59 .BI -iseek\ n\^ 60 Seek 61 .I n 62 records forward on input file 63 before copying. 64 .TP 65 .BI -files\ n\^ 66 Catenate 67 .I n 68 input files (useful only for magnetic tape or similar input device). 69 .TP 70 .BI -oseek\ n\^ 71 Seek 72 .I n\^ 73 records from beginning of output file before copying. 74 .TP 75 .BI -count\ n\^ 76 Copy only 77 .I n 78 input records. 79 .TP 80 .BI -trunc\ n\^ 81 By default, 82 .I dd 83 truncates the output file when it opens it; 84 .B -trunc 85 .B 0 86 opens it without truncation. 87 .TP 88 .BI -quiet\ n\^ 89 By default, 90 .I dd 91 prints the number of blocks read and written 92 once it is finished. 93 .B -quiet 94 .B 1 95 silences this summary. 96 .HP 97 \fL-conv\ ascii\ \ \ \ \fRConvert 98 .SM EBCDIC 99 to 100 .SM ASCII. 101 .PD0 102 .RS "\w'\fLconv\ \fP'u" 103 .TP "\w'\fLunblock\ \ \fP'u" 104 .B ebcdic 105 Convert 106 .SM ASCII 107 to 108 .SM EBCDIC. 109 .TP 110 .B ibm 111 Like 112 .B ebcdic 113 but with a slightly different character map. 114 .TP 115 .B block 116 Convert variable length 117 .SM ASCII 118 records to fixed length. 119 .TP 120 .B unblock 121 Convert fixed length 122 .SM ASCII 123 records to variable length. 124 .TP 125 .B lcase 126 Map alphabetics to lower case. 127 .TP 128 .B ucase 129 Map alphabetics to upper case. 130 .TP 131 .B swab 132 Swap every pair of bytes. 133 .TP 134 .B noerror 135 Do not stop processing on an error. 136 .TP 137 .B sync 138 Pad every input record to 139 .I ibs\^ 140 bytes. 141 .RE 142 .PD 143 .PP 144 .fi 145 Where sizes are specified, 146 a number of bytes is expected. 147 A number may end with 148 .L k 149 or 150 .LR b 151 to specify multiplication by 152 1024 or 512 respectively; 153 a pair of numbers may be separated by 154 .L x 155 to indicate a product. 156 Multiple conversions may be specified in the style: 157 .LR "-conv ebcdic,ucase" . 158 .PP 159 .L Cbs\^ 160 is used only if 161 .LR ascii\^ , 162 .LR unblock\^ , 163 .LR ebcdic\^ , 164 .LR ibm\^ , 165 or 166 .L block\^ 167 conversion is specified. 168 In the first two cases, 169 .I n 170 characters are copied into the conversion buffer, any specified 171 character mapping is done, 172 trailing blanks are trimmed and new-line is added 173 before sending the line to the output. 174 In the latter three cases, characters are read into the 175 conversion buffer and blanks are added to make up an 176 output record of size 177 .IR n . 178 If 179 .L cbs\^ 180 is unspecified or zero, the 181 .LR ascii\^ , 182 .LR ebcdic\^ , 183 and 184 .L ibm\^ 185 options convert the character set without changing the block 186 structure of the input file; the 187 .L unblock\^ 188 and 189 .L block\^ 190 options become a simple file copy. 191 .SH SOURCE 192 .B \*9/src/cmd/dd.c 193 .SH "SEE ALSO" 194 .MR cp (1) 195 .SH DIAGNOSTICS 196 .I Dd 197 reports the number of full + partial input and output 198 blocks handled.