dd

QNX SDP8.0Utilities ReferenceUtilities

Convert a file while copying it (POSIX, toybox)

Syntax:

dd [if|of=file][ibs|obs|bs|count|seek|skip=n] [conv|status|iflag|oflag=flag[,flag...]]

Runs on:

QNX OS

Description:

The dd utility copies a file with a user-selectable block size, while optionally performing conversions on it.

Blocks of data are copied and converted using the following keyword=value modifiers:

bs=n
Set block size in bytes (default is 512).
count=n
Copy only n blocks (by default, all blocks are copied).
ibs=n
Set input block size to n bytes. The default is the value set by b=
if=file
Read from file instead of the standard input.
obs=n
Set the output block size to n bytes. The default is the value set by b=
of=file
Write to file instead of the standard output.
seek=n
Skip n number of output blocks. The default is 0.
skip=n
Skip n number of input blocks. The default is 0.

Each n value accepts the normal unit suffixes (see toybox --help).

These modifiers take a comma-separated list of potential options:
conv= conversion[,conversion...]
excl
Fail if the output file already exists.
fsync
Flush the output file to disk at the end.
nocreat
Fail if the of=file option is missing.
noerror
Continue after read errors.
notrunc
Don't truncate the output file.
sparse
Try to seek past zeroed output.
sync
Pad input blocks with NULs for short reads.
iflag count_bytes, skip_bytes
The count=n or skip=n options are in bytes, not blocks.
oflag=seek_bytes,append
The seek=n option is in bytes, append output to file.
status=noxfer,none
Don't show the transfer rate, no summary info.

This utility is provided as part of the toybox package. For information on how to enable it, see toybox.

Contributing author:

Rob Landley and the toybox project (see https://landley.net/toybox/).

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