.\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.35.
.TH DD "1" "September 2011" "GNU coreutils 8.12.197-032bb" "User Commands"
.SH NAME
dd \- convert and copy a file
.SH SYNOPSIS
.B dd
[\fIOPERAND\fR]...
.br
.B dd
\fIOPTION\fR
.SH DESCRIPTION
.\" Add any additional description here
.PP
Copy a file, converting and formatting according to the operands.
.TP
bs=BYTES
read and write up to BYTES bytes at a time
.TP
cbs=BYTES
convert BYTES bytes at a time
.TP
conv=CONVS
convert the file as per the comma separated symbol list
.TP
count=BLOCKS
copy only BLOCKS input blocks
.TP
ibs=BYTES
read up to BYTES bytes at a time (default: 512)
.TP
if=FILE
read from FILE instead of stdin
.TP
iflag=FLAGS
read as per the comma separated symbol list
.TP
obs=BYTES
write BYTES bytes at a time (default: 512)
.TP
of=FILE
write to FILE instead of stdout
.TP
oflag=FLAGS
write as per the comma separated symbol list
.TP
seek=BLOCKS
skip BLOCKS obs\-sized blocks at start of output
.TP
skip=BLOCKS
skip BLOCKS ibs\-sized blocks at start of input
.TP
status=noxfer
suppress transfer statistics
.PP
BLOCKS and BYTES may be followed by the following multiplicative suffixes:
c =1, w =2, b =512, kB =1000, K =1024, MB =1000*1000, M =1024*1024, xM =M
GB =1000*1000*1000, G =1024*1024*1024, and so on for T, P, E, Z, Y.
.PP
Each CONV symbol may be:
.TP
ascii
from EBCDIC to ASCII
.TP
ebcdic
from ASCII to EBCDIC
.TP
ibm
from ASCII to alternate EBCDIC
.TP
block
pad newline\-terminated records with spaces to cbs\-size
.TP
unblock
replace trailing spaces in cbs\-size records with newline
.TP
lcase
change upper case to lower case
.TP
ucase
change lower case to upper case
.TP
swab
swap every pair of input bytes
.TP
sync
pad every input block with NULs to ibs\-size; when used
with block or unblock, pad with spaces rather than NULs
.TP
excl
fail if the output file already exists
.TP
nocreat
do not create the output file
.TP
notrunc
do not truncate the output file
.TP
noerror
continue after read errors
.TP
fdatasync
physically write output file data before finishing
.TP
fsync
likewise, but also write metadata
.PP
Each FLAG symbol may be:
.TP
append
append mode (makes sense only for output; conv=notrunc suggested)
.TP
direct
use direct I/O for data
.TP
directory
fail unless a directory
.TP
dsync
use synchronized I/O for data
.TP
sync
likewise, but also for metadata
.TP
fullblock
accumulate full blocks of input (iflag only)
.TP
nonblock
use non\-blocking I/O
.TP
noatime
do not update access time
.TP
nocache
discard cached data
.TP
noctty
do not assign controlling terminal from file
.TP
nofollow
do not follow symlinks
.PP
Sending a USR1 signal to a running `dd' process makes it
print I/O statistics to standard error and then resume copying.
.IP
\f(CW$ dd if=/dev/zero of=/dev/null& pid=$!\fR
.br
\f(CW$ kill -USR1 $pid; sleep 1; kill $pid\fR
.IP
18335302+0 records in
18335302+0 records out
9387674624 bytes (9.4 GB) copied, 34.6279 seconds, 271 MB/s
.PP
Options are:
.TP
\fB\-\-help\fR
display this help and exit
.TP
\fB\-\-version\fR
output version information and exit
.SH AUTHOR
Written by Paul Rubin, David MacKenzie, and Stuart Kemp.
.SH "REPORTING BUGS"
Report dd bugs to bug\-coreutils@gnu.org
.br
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
.br
General help using GNU software: <http://www.gnu.org/gethelp/>
.br
Report dd translation bugs to <http://translationproject.org/team/>
.SH COPYRIGHT
Copyright \(co 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
.br
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
.SH "SEE ALSO"
The full documentation for
.B dd
is maintained as a Texinfo manual.  If the
.B info
and
.B dd
programs are properly installed at your site, the command
.IP
.B info coreutils \(aqdd invocation\(aq
.PP
should give you access to the complete manual.