3 dd \- convert and copy a file
12 copies the specified input file
13 to the specified output with
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.
19 .TP \w'\fLoseek\ \ \fIn'u
31 Set input block size to
36 Set output block size (default 512).
39 Set both input and output block size,
44 If no conversion is specified,
45 preserve the input block size instead of packing short blocks
46 into the output buffer.
47 This is particularly efficient since no in-core copy need be done.
50 Set conversion buffer size.
55 input records before copying.
60 records forward on input file
66 input files (useful only for magnetic tape or similar input device).
71 records from beginning of output file before copying.
81 truncates the output file when it opens it;
84 opens it without truncation.
89 prints the number of blocks read and written
93 silences this summary.
95 \fL-conv\ ascii\ \ \ \ \fRConvert
100 .RS "\w'\fLconv\ \fP'u"
101 .TP "\w'\fLunblock\ \ \fP'u"
111 but with a slightly different character map.
114 Convert variable length
116 records to fixed length.
121 records to variable length.
124 Map alphabetics to lower case.
127 Map alphabetics to upper case.
130 Swap every pair of bytes.
133 Do not stop processing on an error.
136 Pad every input record to
143 Where sizes are specified,
144 a number of bytes is expected.
145 A number may end with
149 to specify multiplication by
150 1024 or 512 respectively;
151 a pair of numbers may be separated by
153 to indicate a product.
154 Multiple conversions may be specified in the style:
155 .LR "-conv ebcdic,ucase" .
165 conversion is specified.
166 In the first two cases,
168 characters are copied into the conversion buffer, any specified
169 character mapping is done,
170 trailing blanks are trimmed and new-line is added
171 before sending the line to the output.
172 In the latter three cases, characters are read into the
173 conversion buffer and blanks are added to make up an
174 output record of size
178 is unspecified or zero, the
183 options convert the character set without changing the block
184 structure of the input file; the
188 options become a simple file copy.
195 reports the number of full + partial input and output