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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