DD(1) DOMAIN/IX Reference Manual (SYS5) DD(1)
NAME
dd - convert and copy a file
USAGE
dd [ option=value ] ...
DESCRIPTION
Dd copies the specified input file to the specified output
with possible conversions. By default, it uses the standard
input and output. You may specify the input and output
block size. After completion, dd reports the number of
whole and partial input and output blocks.
OPTION/VALUE PAIRS
ibs=n Input block size n bytes; 512 is the
default.
obs=n Output block size; 512 is the default.
bs=n Set both input and output block size,
superseding ibs and obs; also, if no conver-
sion is specified, it is particularly effi-
cient since no in-core copy has to be done.
cbs=n Conversion buffer size; used only if
conv=ascii or conv=ebcdic is specified. In
the former case, cbs characters are placed
into the conversion buffer, converted to
ASCII, and trimmed of any trailing blanks.
Newlines are then added before sending the
line to the output. In the latter case,
ASCII characters are read into the conver-
sion buffer, converted to EBCDIC, and blanks
are added to make up an output block of size
cbs.
skip=n Skip n input blocks before starting copy.
seek=n Seek n blocks from the beginning of the out-
put file before copying.
count=n Copy only n input blocks.
conv=ascii Convert EBCDIC to ASCII.
ebcdic Convert ASCII to EBCDIC.
ibm Map ASCII to EBCDIC in a slightly different
way than the above case.
lcase Map alphabetics to lowercase.
ucase Map alphabetics to uppercase.
swab Swap every pair of bytes.
noerror Do not stop processing on an error.
sync Pad every input block to ibs.
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DD(1) DOMAIN/IX Reference Manual (SYS5) DD(1)
... , ... Represent several comma-separated conver-
sions.
Where sizes are specified, a number of bytes is expected. A
number may end with k, b, or w to specify multiplication by
1024, 512, or 2, respectively; a pair of numbers may be
separated by x to indicate a product.
The ASCII/EBCDIC conversion tables are taken from the 256-
character standard of the CACM (November, 1968). The ibm
conversion, while less accepted as a standard, corresponds
better to certain IBM print train conventions.
DD-2 Printed 6/10/85
DD(1) DOMAIN/IX Reference Manual (SYS5) DD(1)
EXAMPLE
To read an EBCDIC tape blocked with ten 80-byte EBCDIC card
images per block into the ASCII file x, use the following:
dd if=/dev/rmt0 of=x ibs=800 cbs=80 conv=ascii,lcase
CAUTIONS
DOMAIN/IX does not support some raw I/O devices typically
used with dd.
Newlines are inserted only on conversion to ASCII. Padding
is done only on conversion to EBCDIC. These should be
separate options.
DIAGNOSTICS
f+p blocks in(out)
numbers of full and partial blocks
read(written)
RELATED INFORMATION
cp (1).
Printed 6/10/85 DD-3