dd \- convert and copy a file
copies the specified input file
to the specified output with
The standard input and output are used by default.
The input and output block size may be
specified to take advantage of raw physical I/O.
input file name; standard input is default
output file name; standard output is default
output block size (default 512)
set both input and output block size,
also, if no conversion is specified,
it is particularly efficient since no copy need be done
input records before starting copy
input files before starting copy
records from beginning of output file before copying
slightly different map of ASCII to EBCDIC
map alphabetics to lower case
map alphabetics to upper case
do not stop processing on an error
pad every input record to
several comma-separated conversions
Where sizes are specified,
a number of bytes is expected.
to specify multiplication by
1024, 512, or 2 respectively;
a pair of numbers may be separated by
characters are placed into the conversion buffer, converted to
ASCII, and trailing blanks trimmed and new-line added
before sending the line to the output.
In the latter case ASCII characters are read into the
conversion buffer, converted to EBCDIC, and blanks added
reports the number of whole and partial input and output
For example, to read an EBCDIC tape blocked ten 80-byte
EBCDIC card images per record into the ASCII file
dd if=/dev/rmt0 of=x ibs=800 cbs=80 conv=ascii,lcase
Note the use of raw magtape.
is especially suited to I/O on the raw
physical devices because it allows reading
and writing in arbitrary record sizes.
f+p records in(out): numbers of full and partial records read(written)
The ASCII/EBCDIC conversion tables are
from the 256 character standard in
The `ibm' conversion, while less blessed as a standard,
corresponds better to certain IBM print train conventions.
There is no universal solution.
Newlines are inserted only on conversion to ASCII;
padding is done only on conversion to EBCDIC.
These should be separate options.