dd

Usage: dd [OPERAND]...
 or: dd OPTION
Copy a file, converting and formatting according to the operands.
 bs=BYTES read and write up to BYTES bytes at a time (default: 512);
 overrides ibs and obs
 cbs=BYTES convert BYTES bytes at a time
 conv=CONVS convert the file as per the comma separated symbol list
 count=N copy only N input blocks
 ibs=BYTES read up to BYTES bytes at a time (default: 512)
 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 (default: 512)
 of=FILE write to FILE instead of stdout
 oflag=FLAGS write as per the comma separated symbol list
 seek=N (or oseek=N) skip N obs-sized output blocks
 skip=N (or iseek=N) skip N ibs-sized input blocks
 status=LEVEL The LEVEL of information to print to stderr;
 'none' suppresses everything but error messages,
 'noxfer' suppresses the final transfer statistics,
 'progress' shows periodic transfer statistics
N 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.
Binary prefixes can be used, too: KiB=K, MiB=M, and so on.
If N ends in 'B', it counts bytes not blocks.
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
 ucase change lower case to upper case
 sparse try to seek rather than write all-NUL output blocks
 swab swap every pair of input bytes
 sync pad every input block with NULs to ibs-size; when used
 with block or unblock, pad with spaces rather than NULs
 excl fail if the output file already exists
 nocreat do not create the output file
 notrunc do not truncate the output file
 noerror continue after read errors
 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
 fullblock accumulate full blocks of input (iflag only)
 nonblock use non-blocking I/O
 noatime do not update access time
 nocache Request to drop cache. See also oflag=sync
 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.
Options are:
 --help display this help and exit
 --version output version information and exit
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
Full documentation <https://www.gnu.org/software/coreutils/dd>
or available locally via: info '(coreutils) dd invocation'