2015-02-02 17:34:26 +00:00
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.Dd February 2, 2015
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.Dt DD 1
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.Os ubase
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.Sh NAME
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.Nm dd
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.Nd convert and copy a file
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.Sh SYNOPSIS
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.Nm
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.Op Ar operand...
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.Sh DESCRIPTION
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.Nm
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copies the standard input to the standard output. By default input data is
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read and written in 64kB blocks. When finished,
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.Nm
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displays the number of records read and written as well as the total number
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of bytes copied.
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.Nm
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syncs the filesystem once it is done copying. If you want to disable that use
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the
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.Ar nosync
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option.
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.Sh OPTIONS
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.Bl -tag -width Ds
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.It Ar bs Op Ar [=N]
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If
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.Ar bs
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is not specified, the default blocksize is 64kB. If
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.Ar bs
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is specified
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without setting it to a specific value then an optimal value between the
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source and target filesystem will be selected. If this process fails it will
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fallback to the system's pagesize. Adjust
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.Ar N
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to set the block size of the transfers in bytes.
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.It Ar count=N
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Copy only
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.Ar N
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input blocks.
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.It Ar direct
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2014-06-11 10:49:44 +00:00
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Use direct I/O for data.
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2015-02-02 17:34:26 +00:00
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.It Ar if=file
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Read input from
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.Ar file
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instead of the standard input.
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.It Ar nosync
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2014-06-11 10:49:44 +00:00
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Do not sync the filesystem once we are done copying.
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2015-02-02 17:34:26 +00:00
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.It Ar quiet
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Enable quiet output.
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.It Ar of=file
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Write output to
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.Ar file
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instead of the standard output. If an initial portion of the output
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.Ar file
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is skipped using the seek operand, the output file is truncated at that
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point.
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.It Ar seek=N
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Seek
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.Ar N
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blocks from the beginning of the output before copying.
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.It Ar skip=N
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Skip
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.Ar N blocks from the beginning of the input before copying.
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.El
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