[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH] dd - support for reading of full blocks
From: |
Pádraig Brady |
Subject: |
Re: [PATCH] dd - support for reading of full blocks |
Date: |
Fri, 18 Jul 2008 09:59:12 +0100 |
User-agent: |
Thunderbird 2.0.0.6 (X11/20071008) |
Paul Eggert wrote:
> Pádraig Brady <address@hidden> writes:
>
>> or conv=wait, though I do have a strong preference
>> for iflag=block as it's the most accurate.
>
> I dunno, iflag= is supposed to be symmetric with oflag=.
Well there is no harm in having that oflag as well
to handle short writes, even though it's probably redundant.
> This "feels" more like a conversion, so conv= seems more
> appropriate.
Hmm, there is no obvious right option for me given
the current syntax of dd.
To me, conv should mean that the data is actually
changed in some way. Unfortunately that doesn't seem
to be the case currently as we have the following
conversions which actually modify the data:
ascii from EBCDIC to ASCII
ebcdic from ASCII to EBCDIC
ibm from ASCII to alternate EBCDIC
block pad \n-terminated records with spaces to cbs-size
unblock replace trailing spaces in cbs-size records with \n
lcase change upper case to lower case
ucase change lower case to upper case
swab swap every pair of input bytes
sync pad every input block with NULs to ibs-size;
when used with block or unblock, pad with spaces
But we also have these, which should be flags IMHO:
noerror continue after read errors
notrunc do not truncate the output file
nocreat do not create the output file
excl fail if the output file already exists
fdatasync physically write output file data before finishing
fsync likewise, but also write metadata
Note only noerror and notrunc are specified by POSIX,
and POSIX dd has no flag options at all, so it's excused :)
I do agree that a flag=block is confusing with the existing
conv=block option, so I'm currently 60/40 for iflag=wait/conv=fill
cheers,
Pádraig.
- [PATCH] dd - support for reading of full blocks, Kamil Dudka, 2008/07/17
- Re: [PATCH] dd - support for reading of full blocks, Pádraig Brady, 2008/07/17
- Re: [PATCH] dd - support for reading of full blocks, Kamil Dudka, 2008/07/17
- Re: [PATCH] dd - support for reading of full blocks, Pádraig Brady, 2008/07/17
- Re: [PATCH] dd - support for reading of full blocks, Jim Meyering, 2008/07/18
- Re: [PATCH] dd - support for reading of full blocks, Kamil Dudka, 2008/07/21
- Message not available
- Re: [PATCH] dd - support for reading of full blocks, Kamil Dudka, 2008/07/23
- Re: [PATCH] dd - support for reading of full blocks, Jim Meyering, 2008/07/23
- Re: [PATCH] dd - support for reading of full blocks, Jim Meyering, 2008/07/24