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<p>New page: DD(1) UNIX Programmer&#039;s Manual DD(1) == NAME == dd - convert and copy a file == SYNOPSIS == dd [option=value] ... == DESCRIPTION == _D_d co...</p> <p><b>New page</b></p><div>DD(1) UNIX Programmer's Manual DD(1)<br /> <br /> <br /> <br /> == NAME ==<br /> dd - convert and copy a file<br /> <br /> == SYNOPSIS ==<br /> dd [option=value] ...<br /> <br /> == DESCRIPTION ==<br /> _D_d copies the specified input file to the specified output<br /> with possible conversions. The standard input and output<br /> are used by default. The input and output block size may be<br /> specified to take advantage of raw physical I/O.<br /> <br /> _o_p_t_i_o_n _v_a_l_u_e_s<br /> if= input file name; standard input is default<br /> of= output file name; standard output is default<br /> ibs=_n input block size _n bytes (default 512)<br /> obs=_n output block size (default 512)<br /> bs=_n set both input and output block size,<br /> superseding _i_b_s and _o_b_s; also, if no conver-<br /> sion is specified, it is particularly effi-<br /> cient since no copy need be done<br /> cbs=_n conversion buffer size<br /> skip=_n skip _n input records before starting copy<br /> files=_n skip _n input files before starting copy<br /> seek=_n seek _n records from beginning of output file<br /> before copying<br /> count=_n copy only _n input records<br /> conv=ascii convert EBCDIC to ASCII<br /> ebcdic convert ASCII to EBCDIC<br /> ibm slightly different map of ASCII to EBCDIC<br /> lcase map alphabetics to lower case<br /> ucase map alphabetics to upper case<br /> swab swap every pair of bytes<br /> noerror do not stop processing on an error<br /> sync pad every input record to _i_b_s<br /> ... , ... several comma-separated conversions<br /> <br /> Where sizes are specified, a number of bytes is expected. A<br /> number may end with k, b or w to specify multiplication by<br /> 1024, 512, or 2 respectively; a pair of numbers may be<br /> separated by x to indicate a product.<br /> <br /> _C_b_s is used only if _a_s_c_i_i or _e_b_c_d_i_c conversion is specified.<br /> In the former case _c_b_s characters are placed into the<br /> conversion buffer, converted to ASCII, and trailing blanks<br /> trimmed and new-line added before sending the line to the<br /> output. In the latter case ASCII characters are read into<br /> the conversion buffer, converted to EBCDIC, and blanks added<br /> to make up an output record of size _c_b_s.<br /> <br /> After completion, _d_d reports the number of whole and partial<br /> input and output blocks.<br /> <br /> For example, to read an EBCDIC tape blocked ten 80-byte<br /> EBCDIC card images per record into the ASCII file _x:<br /> <br /> <br /> dd if=/dev/rmt0 of=x ibs=800 cbs=80 conv=ascii,lcase<br /> <br /> Note the use of raw magtape. _D_d is especially suited to I/O<br /> on the raw physical devices because it allows reading and<br /> writing in arbitrary record sizes.<br /> <br /> == SEE ALSO ==<br /> [[32v 1m cp|cp(1)]], [[32v 1m tr|tr(1)]]<br /> <br /> == DIAGNOSTICS ==<br /> f+p records in(out): numbers of full and partial records<br /> read(written)<br /> <br /> == BUGS ==<br /> The ASCII/EBCDIC conversion tables are taken from the 256<br /> character standard in the CACM Nov, 1968. The `ibm' conver-<br /> sion, while less blessed as a standard, corresponds better<br /> to certain IBM print train conventions. There is no univer-<br /> sal solution.<br /> <br /> Newlines are inserted only on conversion to ASCII; padding<br /> is done only on conversion to EBCDIC. These should be<br /> separate options.<br /> <br /> [[Category:32v man section 1]]</div>

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