DD
Section: Misc. Reference Manual Pages (1L)
Updated: GNU File Utilities
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NAME
dd - convert a file while copying it
SYNOPSIS
dd
[--help] [--version]
[if=file] [of=file] [ibs=bytes] [obs=bytes] [bs=bytes] [cbs=bytes]
[skip=blocks] [seek=blocks] [count=blocks]
[conv={ascii,ebcdic,ibm,block,unblock,lcase,ucase,swab,noerror,notrunc,
sync}]
DESCRIPTION
This manual page
documents the GNU version of
dd.
dd
copies a file (from the standard input to the standard output, by
default) with a user-selectable blocksize, while optionally performing
conversions on it.
OPTIONS
Numbers can be followed by a multiplier:
b=512, c=1, k=1024, w=2, xm=number m
- --help
-
Print a usage message on standard output and exit successfully.
- --version
-
Print version information on standard output then exit successfully.
- if=file
-
Read from
file
instead of the standard input.
- of=file
-
Write to
file
instead of the standard output.
Unless
conv=notrunc
is given, truncate
file
to the size specified by
seek=
(0 bytes if
seek=
is not given).
- ibs=bytes
-
Read
bytes
bytes at a time.
- obs=bytes
-
Write
bytes
bytes at a time.
- bs=bytes
-
Read and write
bytes
bytes at atime. Override ibs and obs.
- cbs=bytes
-
Convert
bytes
bytes at a time.
- skip=blocks
-
Skip
blocks
ibs-sized blocks at start of input.
- seek=blocks
-
Skip
blocks
obs-sized blocks at start of output.
- count=blocks
-
Copy only
blocks
ibs-sized input blocks.
- conv=conversion[,conversion...]
-
Convert the file as specified by the
conversion
arguments.
-
Conversions:
- ascii
-
Convert EBCDIC to ASCII.
- ebcdic
-
Convert ASCII to EBCDIC.
- ibm
-
Convert ASCII to alternate EBCDIC.
- block
-
Pad newline-terminated records to size of cbs, replacing newline with
trailing spaces.
- unblock
-
Replace trailing spaces in cbs-sized block with newline.
- lcase
-
Change uppercase characters to lowercase.
- ucase
-
Change lowercase characters to uppercase.
- swab
-
Swap every pair of input bytes. Unlike the Unix dd, this works when
an odd number of bytes are read. If the input file contains an odd
number of bytes, the last byte is simply copied (since there is
nothing to swap it with).
- noerror
-
Continue after read errors.
- notrunc
-
Do not truncate the output file.
- sync
-
Pad every input block to size of ibs with trailing NULs.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- OPTIONS
-
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Time: 06:12:26 GMT, January 05, 2023