DD linux command manual

DD(1)                          User Commands                           DD(1)



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 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 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 (C) 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 PARTICU-
       LAR PURPOSE.

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

       should give you access to the complete manual.



dd (coreutils) 5.2.1               May 2004                             DD(1)