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dd(1) [minix man page]

DD(1)							      General Commands Manual							     DD(1)

NAME
dd - disk dumper SYNOPSIS
dd [option = value] ... EXAMPLES
dd if=/dev/fd0 of=/dev/fd1 # Copy disk 0 to disk 1 dd if=x of=y bs=1w skip=4 # Copy x to y, skipping 4 words dd if=x of=y count=3 # Copy three 512-byte blocks DESCRIPTION
This command is intended for copying partial files. The block size, skip count, and number of blocks to copy can be specified. The options are: if = file - Input file (default is stdin) of = file - Output file (default is standard output) ibs = n - Input block size (default 512 bytes) obs = n - Output block size (default is 512 bytes) bs = n - Block size; sets ibs and obs (default is 512 bytes) skip = n - Skip n input blocks before reading seek = n - Skip n output blocks before writing count = n - Copy only n input blocks conv = lcase - Convert upper case letters to lower case conv = ucase - Convert lower case letters to upper case conv = swab - Swap every pair of bytes conv = noerror- Ignore errors and just keep going conv = silent- Suppress statistics (Minix specific flag) Where sizes are expected, they are in bytes. However, the letters w, b, or k may be appended to the number to indicate words (2 bytes), blocks (512 bytes), or K (1024 bytes), respectively. When dd is finished, it reports the number of full and partial blocks read and writ- ten. SEE ALSO
vol(1). DD(1)

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DD(1)							      General Commands Manual							     DD(1)

NAME
dd - convert and copy a file SYNOPSIS
dd [option=value] ... DESCRIPTION
Dd copies the specified input file to the specified output with possible conversions. The standard input and output are used by default. The input and output block size may be specified to take advantage of raw physical I/O. option values if= input file name; standard input is default of= output file name; standard output is default ibs=n input block size n bytes (default 512) obs=n output block size (default 512) bs=n set both input and output block size, superseding ibs and obs; also, if no conversion is specified, it is particularly effi- cient since no copy need be done cbs=n conversion buffer size skip=n skip n input records before starting copy files=n copy n files from (tape) input seek=n seek n records from beginning of output file before copying count=n copy only n input records conv=ascii convert EBCDIC to ASCII ebcdic convert ASCII to EBCDIC ibm slightly different map of ASCII to EBCDIC lcase map alphabetics to lower case ucase map alphabetics to upper case swab swap every pair of bytes noerror do not stop processing on an error sync pad every input record to ibs ... , ... several comma-separated conversions Where sizes are specified, a number of bytes is expected. A number may end with k, b or w to specify multiplication by 1024, 512, or 2 respectively; a pair of numbers may be separated by x to indicate a product. Cbs is used only if ascii or ebcdic conversion is specified. In the former case cbs characters are placed into the conversion buffer, con- verted to ASCII, and trailing blanks trimmed and new-line added before sending the line to the output. In the latter case ASCII characters are read into the conversion buffer, converted to EBCDIC, and blanks added to make up an output record of size cbs. After completion, dd reports the number of whole and partial input and output blocks. For example, to read an EBCDIC tape blocked ten 80-byte EBCDIC card images per record into the ASCII file x: dd if=/dev/rmt0 of=x ibs=800 cbs=80 conv=ascii,lcase Note the use of raw magtape. Dd is especially suited to I/O on the raw physical devices because it allows reading and writing in arbitrary record sizes. To skip over a file before copying from magnetic tape do (dd of=/dev/null; dd of=x) </dev/rmt0 SEE ALSO
cp(1), tr(1) DIAGNOSTICS
f+p records in(out): numbers of full and partial records read(written) BUGS
The ASCII/EBCDIC conversion tables are taken from the 256 character standard in the CACM Nov, 1968. The `ibm' conversion, while less blessed as a standard, corresponds better to certain IBM print train conventions. There is no universal solution. Newlines are inserted only on conversion to ASCII; padding is done only on conversion to EBCDIC. These should be separate options. DD(1)
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