Add the DragonFly cvs id and perform general cleanups on cvs/rcs/sccs ids. Most
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984263bc
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1.\" Copyright (c) 1990, 1993
2.\" The Regents of the University of California. All rights reserved.
3.\"
4.\" This code is derived from software contributed to Berkeley by
5.\" Keith Muller of the University of California, San Diego.
6.\"
7.\" Redistribution and use in source and binary forms, with or without
8.\" modification, are permitted provided that the following conditions
9.\" are met:
10.\" 1. Redistributions of source code must retain the above copyright
11.\" notice, this list of conditions and the following disclaimer.
12.\" 2. Redistributions in binary form must reproduce the above copyright
13.\" notice, this list of conditions and the following disclaimer in the
14.\" documentation and/or other materials provided with the distribution.
15.\" 3. All advertising materials mentioning features or use of this software
16.\" must display the following acknowledgement:
17.\" This product includes software developed by the University of
18.\" California, Berkeley and its contributors.
19.\" 4. Neither the name of the University nor the names of its contributors
20.\" may be used to endorse or promote products derived from this software
21.\" without specific prior written permission.
22.\"
23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33.\" SUCH DAMAGE.
34.\"
35.\" @(#)dd.1 8.2 (Berkeley) 1/13/94
36.\" $FreeBSD: src/bin/dd/dd.1,v 1.15.2.5 2003/01/24 02:17:12 keramida Exp $
1de703da 37.\" $DragonFly: src/bin/dd/dd.1,v 1.2 2003/06/17 04:22:49 dillon Exp $
984263bc
MD
38.\"
39.Dd January 13, 1994
40.Dt DD 1
41.Os
42.Sh NAME
43.Nm dd
44.Nd convert and copy a file
45.Sh SYNOPSIS
46.Nm
47.Op Ar operands ...
48.Sh DESCRIPTION
49The
50.Nm
51utility copies the standard input to the standard output.
52Input data is read and written in 512-byte blocks.
53If input reads are short, input from multiple reads are aggregated
54to form the output block.
55When finished,
56.Nm
57displays the number of complete and partial input and output blocks
58and truncated input records to the standard error output.
59.Pp
60The following operands are available:
61.Bl -tag -width ".Cm of Ns = Ns Ar file"
62.It Cm bs Ns = Ns Ar n
63Set both input and output block size to
64.Ar n
65bytes, superseding the
66.Cm ibs
67and
68.Cm obs
69operands.
70If no conversion values other than
71.Cm noerror ,
72.Cm notrunc
73or
74.Cm sync
75are specified, then each input block is copied to the output as a
76single block without any aggregation of short blocks.
77.It Cm cbs Ns = Ns Ar n
78Set the conversion record size to
79.Ar n
80bytes.
81The conversion record size is required by the record oriented conversion
82values.
83.It Cm count Ns = Ns Ar n
84Copy only
85.Ar n
86input blocks.
87.It Cm files Ns = Ns Ar n
88Copy
89.Ar n
90input files before terminating.
91This operand is only applicable when the input device is a tape.
92.It Cm ibs Ns = Ns Ar n
93Set the input block size to
94.Ar n
95bytes instead of the default 512.
96.It Cm if Ns = Ns Ar file
97Read input from
98.Ar file
99instead of the standard input.
100.It Cm iseek Ns = Ns Ar n
101Seek on the input file
102.Ar n
103blocks.
104This is synonymous with
105.Cm skip Ns = Ns Ar n .
106.It Cm obs Ns = Ns Ar n
107Set the output block size to
108.Ar n
109bytes instead of the default 512.
110.It Cm of Ns = Ns Ar file
111Write output to
112.Ar file
113instead of the standard output.
114Any regular output file is truncated unless the
115.Cm notrunc
116conversion value is specified.
117If an initial portion of the output file is seeked past (see the
118.Cm oseek
119operand),
120the output file is truncated at that point.
121.It Cm oseek Ns = Ns Ar n
122Seek on the output file
123.Ar n
124blocks.
125This is synonymous with
126.Cm seek Ns = Ns Ar n .
127.It Cm seek Ns = Ns Ar n
128Seek
129.Ar n
130blocks from the beginning of the output before copying.
131On non-tape devices, an
132.Xr lseek 2
133operation is used.
134Otherwise, existing blocks are read and the data discarded.
135If the user does not have read permission for the tape, it is positioned
136using the tape
137.Xr ioctl 2
138function calls.
139If the seek operation is past the end of file, space from the current
140end of file to the specified offset is filled with blocks of
141.Dv NUL
142bytes.
143.It Cm skip Ns = Ns Ar n
144Skip
145.Ar n
146blocks from the beginning of the input before copying.
147On input which supports seeks, an
148.Xr lseek 2
149operation is used.
150Otherwise, input data is read and discarded.
151For pipes, the correct number of bytes is read.
152For all other devices, the correct number of blocks is read without
153distinguishing between a partial or complete block being read.
154.It Cm conv Ns = Ns Ar value Ns Op , Ns Ar value ...
155Where
156.Cm value
157is one of the symbols from the following list.
158.Bl -tag -width ".Cm unblock"
159.It Cm ascii , oldascii
160The same as the
161.Cm unblock
162value except that characters are translated from
163.Tn EBCDIC
164to
165.Tn ASCII
166before the
167records are converted.
168(These values imply
169.Cm unblock
170if the operand
171.Cm cbs
172is also specified.)
173There are two conversion maps for
174.Tn ASCII .
175The value
176.Cm ascii
177specifies the recommended one which is compatible with
178.At V .
179The value
180.Cm oldascii
181specifies the one used in historic
182.At
183and
184.No pre- Ns Bx 4.3 reno
185systems.
186.It Cm block
187Treats the input as a sequence of newline or end-of-file terminated variable
188length records independent of input and output block boundaries.
189Any trailing newline character is discarded.
190Each input record is converted to a fixed length output record where the
191length is specified by the
192.Cm cbs
193operand.
194Input records shorter than the conversion record size are padded with spaces.
195Input records longer than the conversion record size are truncated.
196The number of truncated input records, if any, are reported to the standard
197error output at the completion of the copy.
198.It Cm ebcdic , ibm , oldebcdic , oldibm
199The same as the
200.Cm block
201value except that characters are translated from
202.Tn ASCII
203to
204.Tn EBCDIC
205after the
206records are converted.
207(These values imply
208.Cm block
209if the operand
210.Cm cbs
211is also specified.)
212There are four conversion maps for
213.Tn EBCDIC .
214The value
215.Cm ebcdic
216specifies the recommended one which is compatible with
217.At V .
218The value
219.Cm ibm
220is a slightly different mapping, which is compatible with the
221.At V
222.Cm ibm
223value.
224The values
225.Cm oldebcdic
226and
227.Cm oldibm
228are maps used in historic
229.At
230and
231.No pre- Ns Bx 4.3 reno
232systems.
233.It Cm lcase
234Transform uppercase characters into lowercase characters.
235.It Cm noerror
236Do not stop processing on an input error.
237When an input error occurs, a diagnostic message followed by the current
238input and output block counts will be written to the standard error output
239in the same format as the standard completion message.
240If the
241.Cm sync
242conversion is also specified, any missing input data will be replaced
243with
244.Dv NUL
245bytes (or with spaces if a block oriented conversion value was
246specified) and processed as a normal input buffer.
247If the
248.Cm sync
249conversion is not specified, the input block is omitted from the output.
250On input files which are not tapes or pipes, the file offset
251will be positioned past the block in which the error occurred using
252.Xr lseek 2 .
253.It Cm notrunc
254Do not truncate the output file.
255This will preserve any blocks in the output file not explicitly written
256by
257.Nm .
258The
259.Cm notrunc
260value is not supported for tapes.
261.It Cm osync
262Pad the final output block to the full output block size.
263If the input file is not a multiple of the output block size
264after conversion, this conversion forces the final output block
265to be the same size as preceding blocks for use on devices that require
266regularly sized blocks to be written.
267This option is incompatible with use of the
268.Cm bs Ns = Ns Ar n
269block size specification.
270.It Cm sparse
271If one or more output blocks would consist solely of
272.Dv NUL
273bytes, try to seek the output file by the required space instead of
274filling them with
275.Dv NUL Ns s ,
276resulting in a sparse file.
277.It Cm swab
278Swap every pair of input bytes.
279If an input buffer has an odd number of bytes, the last byte will be
280ignored during swapping.
281.It Cm sync
282Pad every input block to the input buffer size.
283Spaces are used for pad bytes if a block oriented conversion value is
284specified, otherwise
285.Dv NUL
286bytes are used.
287.It Cm ucase
288Transform lowercase characters into uppercase characters.
289.It Cm unblock
290Treats the input as a sequence of fixed length records independent of input
291and output block boundaries.
292The length of the input records is specified by the
293.Cm cbs
294operand.
295Any trailing space characters are discarded and a newline character is
296appended.
297.El
298.El
299.Pp
300Where sizes are specified, a decimal, octal, or hexadecimal number of
301bytes is expected.
302If the number ends with a
303.Dq Li b ,
304.Dq Li k ,
305.Dq Li m ,
306.Dq Li g ,
307or
308.Dq Li w ,
309the
310number is multiplied by 512, 1024 (1K), 1048576 (1M), 1073741824 (1G)
311or the number of bytes in an integer, respectively.
312Two or more numbers may be separated by an
313.Dq Li x
314to indicate a product.
315.Pp
316When finished,
317.Nm
318displays the number of complete and partial input and output blocks,
319truncated input records and odd-length byte-swapping blocks to the
320standard error output.
321A partial input block is one where less than the input block size
322was read.
323A partial output block is one where less than the output block size
324was written.
325Partial output blocks to tape devices are considered fatal errors.
326Otherwise, the rest of the block will be written.
327Partial output blocks to character devices will produce a warning message.
328A truncated input block is one where a variable length record oriented
329conversion value was specified and the input line was too long to
330fit in the conversion record or was not newline terminated.
331.Pp
332Normally, data resulting from input or conversion or both are aggregated
333into output blocks of the specified size.
334After the end of input is reached, any remaining output is written as
335a block.
336This means that the final output block may be shorter than the output
337block size.
338.Pp
339If
340.Nm
341receives a
342.Dv SIGINFO
343(see the
344.Cm status
345argument for
346.Xr stty 1 )
347signal, the current input and output block counts will
348be written to the standard error output
349in the same format as the standard completion message.
350If
351.Nm
352receives a
353.Dv SIGINT
354signal, the current input and output block counts will
355be written to the standard error output
356in the same format as the standard completion message and
357.Nm
358will exit.
359.Sh DIAGNOSTICS
360.Ex -std
361.Sh SEE ALSO
362.Xr cp 1 ,
363.Xr mt 1 ,
364.Xr tr 1
365.Sh STANDARDS
366The
367.Nm
368utility is expected to be a superset of the
369.St -p1003.2
370standard.
371The
372.Cm files
373operand and the
374.Cm ascii ,
375.Cm ebcdic ,
376.Cm ibm ,
377.Cm oldascii ,
378.Cm oldebcdic
379and
380.Cm oldibm
381values are extensions to the
382.Tn POSIX
383standard.