dc3dd

Langue: en

Version: March 2009 (fedora - 04/07/09)

Section: 1 (Commandes utilisateur)

NAME

dc3dd - convert and copy a file

SYNOPSIS

dc3dd [OPERAND]...
dc3dd OPTION

DESCRIPTION

Copy a file, converting and formatting according to the operands.

bs=BYTES
force ibs=BYTES and obs=BYTES
cbs=BYTES
convert BYTES bytes at a time
conv=CONVS
convert the file as per the comma separated symbol list
count=SECTORS
copy only SECTORS input sectors
ibs=BYTES
read BYTES bytes at a time (must be a multiple of input sector size)
if=FILE
read from FILE instead of stdin
ifjoin=BASE.FMT
read from split files with name BASE and splitformat FMT
iflag=FLAGS
read as per the comma separated symbol list
pattern=HEX
write HEX to every byte of the output
textpattern=TEXT
write the string TEXT repeatedly to the output
obs=BYTES
write BYTES bytes at a time
of=FILE
write to FILE instead of stdout
of:=COMMAND
pipe output to the given command
oflag=FLAGS
write as per the comma separated symbol list
wipe=FILE
wipe device FILE with zeros (or specify pattern/textpattern)
seek=SECTORS
skip SECTORS input sectors at start of output
skip=SECTORS
skip SECTORS input sectors at start of input
status=noxfer
suppress transfer statistics
split=BYTES
split the output into pieces of size BYTES
splitformat=FMT
create extensions for split pieces using FMT
Extensions can be numerical starting at zero, numerical starting at one, or alphabetical. These options are selected by using a series of zeros, ones, or a's, respectively. The number of characters used indicates the desired length of the extensions. For example, splitformat=1111 indicates four character numerical extensions starting with 0001.
progress=on
displays a progress meter
progresscount=NUM
number of blocks processed between each progress update
sizeprobe=on
estimates size of input file for use with status
hash=ALGORITHM
computes ALGORITHM hashes of the input data
hashconv=WHEN
determines when data should be hashed, either before or after conversions
hashwindow=BYTES
number of bytes for piecewise hashing
hashlog=FILE
appends piecewise hashes to the log file
errlog=FILE
appends errors to the log file
log=FILE
appends hashes and errors to the same file
errors=group
group read errors together
vf=FILE
verify the input against FILE
vfjoin=BASE.FMT verify the input against split files with name BASE and splitformat FMT verifylog=FILE write the results of the verify to the given file

ALGORITHM can be a comma separated list of md5, sha1, sha256, and sha512

BLOCKS and BYTES may be followed by the following multiplicative suffixes: xM M, c 1, w 2, b 512, kB 1000, K 1024, MB 1000*1000, M 1024*1024, GB 1000*1000*1000, G 1024*1024*1024, and so on for T, P, E, Z, Y.

Each CONV symbol may be:

ascii
from EBCDIC to ASCII
ebcdic
from ASCII to EBCDIC
ibm
from ASCII to alternate EBCDIC
block
pad newline-terminated records with spaces to cbs-size
unblock
replace trailing spaces in cbs-size records with newline
lcase
change upper case to lower case
nocreat
do not create the output file
excl
fail if the output file already exists
notrunc
do not truncate the output file
ucase
change lower case to upper case
swab
swap every pair of input bytes
noerror
continue after read errors
sync
pad every input block with NULs to ibs-size; when used with block or unblock, pad with spaces rather than NULs
fdatasync
physically write output file data before finishing
fsync
likewise, but also write metadata

Each FLAG symbol may be:

append
append mode (makes sense only for output; conv=notrunc suggested)
direct
use direct I/O for data
directory fail unless a directory dsync use synchronized I/O for data sync likewise, but also for metadata nonblock use non-blocking I/O noatime do not update access time noctty do not assign controlling terminal from file nofollow do not follow symlinks

Sending a USR1 signal to a running `dd' process makes it print I/O statistics to standard error and then resume copying.

$ dd if=/dev/zero of=/dev/null& pid=$!
$ kill -USR1 $pid; sleep 1; kill $pid
18335302+0 sectors in 18335302+0 sectors out 9387674624 bytes (9.4 GB) copied, 34.6279 seconds, 271 MB/s

Options are:

--help
display this help and exit
--version
output version information and exit
--flags
display compile-time flags

AUTHOR

Written by Paul Rubin, David MacKenzie, Stuart Kemp, and patched for DC3 by Jesse Kornblum and Andrew Medico.

REPORTING BUGS

Report bugs to <dc3dd@dc3.mil>. Copyright © 2008 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

SEE ALSO

The full documentation for dc3dd is maintained as a Texinfo manual. If the info and dc3dd programs are properly installed at your site, the command
info dc3dd

should give you access to the complete manual.