Dd

NAME
dd - convert and copy a file

SYNOPSIS
dd [OPTION]...

DESCRIPTION
Copy a file, converting and formatting according to the options.
 * bs=BYTES
 * force ibs=BYTES and obs=BYTES


 * cbs=BYTES
 * convert BYTES bytes at a time


 * conv=KEYWORDS
 * convert the file as per the comma separated keyword list


 * count=BLOCKS
 * copy only BLOCKS input blocks


 * ibs=BYTES
 * read BYTES bytes at a time


 * if=FILE
 * read from FILE instead of stdin


 * obs=BYTES
 * write BYTES bytes at a time


 * of=FILE
 * write to FILE instead of stdout


 * seek=BLOCKS
 * skip BLOCKS obs-sized blocks at start of output


 * skip=BLOCKS
 * skip BLOCKS ibs-sized blocks at start of input


 * --help
 * display this help and exit


 * --version
 * output version information and exit

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 KEYWORD may be:
 * ascii - from EBCDIC to ASCII
 * ebcdic - from ASCII to EBCDIC
 * ibm - from ASCII to alternated 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
 * 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

Note that sending a SIGUSR1 signal to a running `dd' process makes it print to standard error the number of records read and written so far, then to resume copying. $ dd if=/dev/zero of=/dev/null& pid=$! $ kill -USR1 $pid; sleep 1; kill $pid 10899206+0 records in 10899206+0 records out

AUTHOR
Written by Paul Rubin, David MacKenzie, and Stuart Kemp.

REPORTING BUGS
Report bugs to .

COPYRIGHT
Copyright &copy; 2004 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Edit Log

 * 2005-06-25 Created from Linux manpage (Ubuntu hoary)