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DD(1)				 User Commands				 DD(1)

NAME
       dd - convert and	copy a file

SYNOPSIS
       dd [OPERAND]...
       dd 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=BLOCKS
	      copy only	BLOCKS input blocks

       ibs=BYTES
	      read BYTES bytes at a time

       if=FILE
	      read from	FILE instead of	stdin

       iflag=FLAGS
	      read as per the comma separated symbol list

       obs=BYTES
	      write BYTES bytes	at a time

       of=FILE
	      write to FILE instead of stdout

       oflag=FLAGS
	      write as per the comma separated symbol list

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

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

       status=noxfer
	      suppress transfer	statistics

       BLOCKS  and  BYTES may be followed by the following multiplicative suf-
       fixes: 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 sug-
	      gested)

       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 fullblock
	      accumulate full blocks  of  input	 (iflag	 only)	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 sta-
       tistics to standard error and then resume copying.

	      $	dd if=/dev/zero	of=/dev/null& pid=$!
	      $	kill -USR1 $pid; sleep 1; kill $pid

	      18335302+0 records in 18335302+0 records	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

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

REPORTING BUGS
       Report bugs to <bug-coreutils@gnu.org>.

COPYRIGHT
       Copyright  (C) 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 dd	is maintained as a Texinfo manual.  If
       the info	and dd programs	are properly installed at your site, the  com-
       mand

	      info coreutils 'dd invocation'

       should give you access to the complete manual.

GNU coreutils 6.12		  March	2009				 DD(1)

NAME | SYNOPSIS | DESCRIPTION | AUTHOR | REPORTING BUGS | COPYRIGHT | SEE ALSO

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