MPE/iX Shell and Utilities Reference Manual, Vol 1

dd(1) MPE/iX Shell and Utilities dd(1)
sync pads any input block shorter than ibs to that size with null bytes
before conversion and output. If you also specified block or
unblock, dd uses spaces instead of null bytes for padding.
ucase converts lowercase input to uppercase.
unblock converts fixed-length records to variable-length records by reading
a number of bytes equal to the size of the conversion buffer, delet-
ing all trailing spaces, and appending a newline character. You
must specify cbs=size with this conversion.
convfile uses convfile as a translation table if it is not one of the conversion
formats listed here and it is the name of a file of exactly 256 bytes.
You may perform multiple conversions at the same time by separating arguments to
conv with commas; however, some conversions are mutually exclusive (for
example, ucase and lcase).
count=n
copies only n input blocks to the output.
ibs=size
sets the input block size to size bytes. You specify it in the same way as bs.
if=file reads input data from file. If you don’t specify this option, dd reads data from the
standard input.
imsg=string
displays string when all data has been read from the current volume, replacing all
occurrences of %d in string with the number of the next volume to be read. dd then
reads and discards a line from the controlling terminal, giving you a chance to
change volumes (usually diskettes).
iseek=n
seeks to the nth block of the input file. The distinction between this and skip is that
iseek does not read the discarded data; however there are some devices, such as
tape drives and communication lines, on which seeking is not possible, so only skip
is appropriate.
obs=size
sets the output block size to size bytes. You specify it in the same way as the bs
value. The size of the destination should be a multiple of the value chosen for size.
For example, if you choose obs=10k, the destination’s size should be a multiple of
10k.
1-170 Commands and Utilities