1 11a3ce57 2011-08-16 rsc .TH DD 1
  2 11a3ce57 2011-08-16 rsc .SH NAME
  3 11a3ce57 2011-08-16 rsc dd \- convert and copy a file
  4 11a3ce57 2011-08-16 rsc .SH SYNOPSIS
  5 11a3ce57 2011-08-16 rsc .B dd
  6 11a3ce57 2011-08-16 rsc [
  7 11a3ce57 2011-08-16 rsc .I option value
  8 11a3ce57 2011-08-16 rsc ]
  9 11a3ce57 2011-08-16 rsc \&...
 10 11a3ce57 2011-08-16 rsc .SH DESCRIPTION
 11 11a3ce57 2011-08-16 rsc .I Dd\^
 12 11a3ce57 2011-08-16 rsc copies the specified input file
 13 11a3ce57 2011-08-16 rsc to the specified output with
 14 11a3ce57 2011-08-16 rsc possible conversions.
 15 11a3ce57 2011-08-16 rsc The standard input and output are used by default.
 16 11a3ce57 2011-08-16 rsc The input and output block size may be
 17 11a3ce57 2011-08-16 rsc specified to take advantage of raw physical I/O.
 18 11a3ce57 2011-08-16 rsc The options are
 19 11a3ce57 2011-08-16 rsc .TF "quiet\ \ \fIn
 20 11a3ce57 2011-08-16 rsc .PD
 21 11a3ce57 2011-08-16 rsc .TP
 22 11a3ce57 2011-08-16 rsc .BI -if\  f
 23 11a3ce57 2011-08-16 rsc Open file
 24 11a3ce57 2011-08-16 rsc .I f
 25 11a3ce57 2011-08-16 rsc for input.
 26 11a3ce57 2011-08-16 rsc .TP
 27 11a3ce57 2011-08-16 rsc .BI -of\  f
 28 11a3ce57 2011-08-16 rsc Open file
 29 11a3ce57 2011-08-16 rsc .I f
 30 11a3ce57 2011-08-16 rsc for output.
 31 11a3ce57 2011-08-16 rsc .TP
 32 11a3ce57 2011-08-16 rsc .BI -ibs\  n\^
 33 11a3ce57 2011-08-16 rsc Set input block size to
 34 11a3ce57 2011-08-16 rsc .I n\^
 35 11a3ce57 2011-08-16 rsc bytes (default 512).
 36 11a3ce57 2011-08-16 rsc .TP
 37 11a3ce57 2011-08-16 rsc .BI -obs\  n\^
 38 11a3ce57 2011-08-16 rsc Set output block size (default 512).
 39 11a3ce57 2011-08-16 rsc .TP
 40 11a3ce57 2011-08-16 rsc .BI -bs\  n\^
 41 11a3ce57 2011-08-16 rsc Set both input and output block size,
 42 11a3ce57 2011-08-16 rsc superseding
 43 11a3ce57 2011-08-16 rsc .I ibs\^
 44 11a3ce57 2011-08-16 rsc and
 45 11a3ce57 2011-08-16 rsc .IR obs .
 46 11a3ce57 2011-08-16 rsc If no conversion is specified,
 47 11a3ce57 2011-08-16 rsc preserve the input block size instead of packing short blocks
 48 11a3ce57 2011-08-16 rsc into the output buffer.
 49 11a3ce57 2011-08-16 rsc This is particularly efficient since no in-core copy need be done.
 50 11a3ce57 2011-08-16 rsc .TP
 51 11a3ce57 2011-08-16 rsc .BI -cbs\  n\^
 52 11a3ce57 2011-08-16 rsc Set conversion buffer size.
 53 11a3ce57 2011-08-16 rsc .TP
 54 11a3ce57 2011-08-16 rsc .BI -skip\  n\^
 55 11a3ce57 2011-08-16 rsc Skip
 56 11a3ce57 2011-08-16 rsc .I n
 57 11a3ce57 2011-08-16 rsc input records before copying.
 58 11a3ce57 2011-08-16 rsc .TP
 59 11a3ce57 2011-08-16 rsc .BI -iseek\  n\^
 60 11a3ce57 2011-08-16 rsc Seek
 61 11a3ce57 2011-08-16 rsc .I n
 62 11a3ce57 2011-08-16 rsc records forward on input file
 63 11a3ce57 2011-08-16 rsc before copying.
 64 11a3ce57 2011-08-16 rsc .TP
 65 11a3ce57 2011-08-16 rsc .BI -files\  n\^
 66 11a3ce57 2011-08-16 rsc Catenate
 67 11a3ce57 2011-08-16 rsc .I n 
 68 11a3ce57 2011-08-16 rsc input files (useful only for magnetic tape or similar input device).
 69 11a3ce57 2011-08-16 rsc .TP
 70 11a3ce57 2011-08-16 rsc .BI -oseek\  n\^
 71 11a3ce57 2011-08-16 rsc Seek
 72 11a3ce57 2011-08-16 rsc .I n\^
 73 11a3ce57 2011-08-16 rsc records from beginning of output file before copying.
 74 11a3ce57 2011-08-16 rsc .TP
 75 11a3ce57 2011-08-16 rsc .BI -count\  n\^
 76 11a3ce57 2011-08-16 rsc Copy only
 77 11a3ce57 2011-08-16 rsc .I n
 78 11a3ce57 2011-08-16 rsc input records.
 79 11a3ce57 2011-08-16 rsc .TP
 80 11a3ce57 2011-08-16 rsc .BI -trunc\  n\^
 81 11a3ce57 2011-08-16 rsc By default,
 82 11a3ce57 2011-08-16 rsc .I dd
 83 11a3ce57 2011-08-16 rsc truncates the output file when it opens it;
 84 11a3ce57 2011-08-16 rsc .B -trunc
 85 11a3ce57 2011-08-16 rsc .B 0
 86 11a3ce57 2011-08-16 rsc opens it without truncation.
 87 11a3ce57 2011-08-16 rsc .TP
 88 11a3ce57 2011-08-16 rsc .BI -quiet\  n\^
 89 11a3ce57 2011-08-16 rsc By default,
 90 11a3ce57 2011-08-16 rsc .I dd
 91 11a3ce57 2011-08-16 rsc prints the number of blocks read and written
 92 11a3ce57 2011-08-16 rsc once it is finished.
 93 11a3ce57 2011-08-16 rsc .B -quiet
 94 11a3ce57 2011-08-16 rsc .B 1
 95 11a3ce57 2011-08-16 rsc silences this summary.
 96 11a3ce57 2011-08-16 rsc .HP
 97 11a3ce57 2011-08-16 rsc \fL-conv\ ascii\ \ \ \ \fRConvert
 98 11a3ce57 2011-08-16 rsc .SM EBCDIC
 99 11a3ce57 2011-08-16 rsc to
100 11a3ce57 2011-08-16 rsc .SM ASCII.
101 11a3ce57 2011-08-16 rsc .PD0
102 11a3ce57 2011-08-16 rsc .RS "\w'\fLconv\ \fP'u"
103 11a3ce57 2011-08-16 rsc .TP "\w'\fLunblock\ \ \fP'u"
104 11a3ce57 2011-08-16 rsc .B ebcdic
105 11a3ce57 2011-08-16 rsc Convert
106 11a3ce57 2011-08-16 rsc .SM ASCII
107 11a3ce57 2011-08-16 rsc to
108 11a3ce57 2011-08-16 rsc .SM EBCDIC.
109 11a3ce57 2011-08-16 rsc .TP
110 11a3ce57 2011-08-16 rsc .B ibm
111 11a3ce57 2011-08-16 rsc Like
112 11a3ce57 2011-08-16 rsc .B ebcdic
113 11a3ce57 2011-08-16 rsc but with a slightly different character map.
114 11a3ce57 2011-08-16 rsc .TP
115 11a3ce57 2011-08-16 rsc .B block
116 11a3ce57 2011-08-16 rsc Convert variable length
117 11a3ce57 2011-08-16 rsc .SM ASCII
118 11a3ce57 2011-08-16 rsc records to fixed length.
119 11a3ce57 2011-08-16 rsc .TP
120 11a3ce57 2011-08-16 rsc .B unblock
121 11a3ce57 2011-08-16 rsc Convert fixed length
122 11a3ce57 2011-08-16 rsc .SM ASCII
123 11a3ce57 2011-08-16 rsc records to variable length.
124 11a3ce57 2011-08-16 rsc .TP
125 11a3ce57 2011-08-16 rsc .B lcase
126 11a3ce57 2011-08-16 rsc Map alphabetics to lower case.
127 11a3ce57 2011-08-16 rsc .TP
128 11a3ce57 2011-08-16 rsc .B ucase
129 11a3ce57 2011-08-16 rsc Map alphabetics to upper case.
130 11a3ce57 2011-08-16 rsc .TP
131 11a3ce57 2011-08-16 rsc .B swab
132 11a3ce57 2011-08-16 rsc Swap every pair of bytes.
133 11a3ce57 2011-08-16 rsc .TP
134 11a3ce57 2011-08-16 rsc .B noerror
135 11a3ce57 2011-08-16 rsc Do not stop processing on an error.
136 11a3ce57 2011-08-16 rsc .TP
137 11a3ce57 2011-08-16 rsc .B sync
138 11a3ce57 2011-08-16 rsc Pad every input record to
139 11a3ce57 2011-08-16 rsc .I  ibs\^
140 11a3ce57 2011-08-16 rsc bytes.
141 11a3ce57 2011-08-16 rsc .RE
142 11a3ce57 2011-08-16 rsc .PD
143 11a3ce57 2011-08-16 rsc .PP
144 11a3ce57 2011-08-16 rsc .fi
145 11a3ce57 2011-08-16 rsc Where sizes are specified,
146 11a3ce57 2011-08-16 rsc a number of bytes is expected.
147 11a3ce57 2011-08-16 rsc A number may end with
148 11a3ce57 2011-08-16 rsc .L k
149 11a3ce57 2011-08-16 rsc or
150 11a3ce57 2011-08-16 rsc .LR b
151 11a3ce57 2011-08-16 rsc to specify multiplication by
152 11a3ce57 2011-08-16 rsc 1024 or 512 respectively;
153 11a3ce57 2011-08-16 rsc a pair of numbers may be separated by
154 11a3ce57 2011-08-16 rsc .L x
155 11a3ce57 2011-08-16 rsc to indicate a product.
156 11a3ce57 2011-08-16 rsc Multiple conversions may be specified in the style:
157 11a3ce57 2011-08-16 rsc .LR "-conv ebcdic,ucase" .
158 11a3ce57 2011-08-16 rsc .PP
159 11a3ce57 2011-08-16 rsc .L Cbs\^
160 11a3ce57 2011-08-16 rsc is used only if
161 11a3ce57 2011-08-16 rsc .LR ascii\^ ,
162 11a3ce57 2011-08-16 rsc .LR unblock\^ ,
163 11a3ce57 2011-08-16 rsc .LR ebcdic\^ ,
164 11a3ce57 2011-08-16 rsc .LR ibm\^ ,
165 11a3ce57 2011-08-16 rsc or
166 11a3ce57 2011-08-16 rsc .L block\^
167 11a3ce57 2011-08-16 rsc conversion is specified.
168 11a3ce57 2011-08-16 rsc In the first two cases,
169 11a3ce57 2011-08-16 rsc .I n
170 11a3ce57 2011-08-16 rsc characters are copied into the conversion buffer, any specified
171 11a3ce57 2011-08-16 rsc character mapping is done,
172 11a3ce57 2011-08-16 rsc trailing blanks are trimmed and new-line is added
173 11a3ce57 2011-08-16 rsc before sending the line to the output.
174 11a3ce57 2011-08-16 rsc In the latter three cases, characters are read into the
175 11a3ce57 2011-08-16 rsc conversion buffer and blanks are added to make up an
176 11a3ce57 2011-08-16 rsc output record of size
177 11a3ce57 2011-08-16 rsc .IR n .
178 11a3ce57 2011-08-16 rsc If
179 11a3ce57 2011-08-16 rsc .L cbs\^
180 11a3ce57 2011-08-16 rsc is unspecified or zero, the
181 11a3ce57 2011-08-16 rsc .LR ascii\^ ,
182 11a3ce57 2011-08-16 rsc .LR ebcdic\^ ,
183 11a3ce57 2011-08-16 rsc and
184 11a3ce57 2011-08-16 rsc .L ibm\^
185 11a3ce57 2011-08-16 rsc options convert the character set without changing the block
186 11a3ce57 2011-08-16 rsc structure of the input file; the
187 11a3ce57 2011-08-16 rsc .L unblock\^
188 11a3ce57 2011-08-16 rsc and
189 11a3ce57 2011-08-16 rsc .L block\^
190 11a3ce57 2011-08-16 rsc options become a simple file copy.
191 11a3ce57 2011-08-16 rsc .SH SOURCE
192 11a3ce57 2011-08-16 rsc .B \*9/src/cmd/dd.c
193 11a3ce57 2011-08-16 rsc .SH "SEE ALSO"
194 d32deab1 2020-08-16 rsc .MR cp (1)
195 11a3ce57 2011-08-16 rsc .SH DIAGNOSTICS
196 11a3ce57 2011-08-16 rsc .I Dd
197 11a3ce57 2011-08-16 rsc reports the number of full + partial input and output
198 11a3ce57 2011-08-16 rsc blocks handled.