From: steve jenkin <sjenkin@canb.auug.org.au>
To: COFF <coff@tuhs.org>
Subject: [COFF] Re: Shell script advice: using 'dd' to write multiple media
Date: Tue, 27 Jun 2023 17:53:41 +1000 [thread overview]
Message-ID: <B0EDE921-CB6B-4517-B6D3-3831EF343AC9@canb.auug.org.au> (raw)
In-Reply-To: <20230627062316.858C6220E5@orac.inputplus.co.uk>
Ralph,
Nice solution:
examine dd’s STDERR then ‘break’.
Thanks for the test script - I like your generation of characters using ‘dc’.
cheers!
steve
> On 27 Jun 2023, at 16:23, Ralph Corderoy <ralph@inputplus.co.uk> wrote:
>
> Hi Steve,
>
>> I’ve never figured out how to use ‘dd’ so it returns after a single
>> block is written doesn’t close the input, killing the pipeline, or
>> cause the rest of the data to be discarded.
>
> I think this meets your description and complies with POSIX's dd(1p)
> here.
>
> $ seq 33 126 | sed 's/$/P/' | dc |
>> while :; do
>> LC_ALL=C dd bs=10 count=1 2>dd.err | sed -n l
>> grep -q '^[^0].* records in$' dd.err || break
>> done
> !"#$%&'()*$
> +,-./01234$
> 56789:;<=>$
> ?@ABCDEFGH$
> IJKLMNOPQR$
> STUVWXYZ[\\$
> ]^_`abcdef$
> ghijklmnop$
> qrstuvwxyz$
> {|}~$
> $
> $ rm dd.err
>
> I set the locale so the format of dd's stderr report is known.
>
> --
> Cheers, Ralph.
--
Steve Jenkin, IT Systems and Design
0412 786 915 (+61 412 786 915)
PO Box 38, Kippax ACT 2615, AUSTRALIA
mailto:sjenkin@canb.auug.org.au http://members.tip.net.au/~sjenkin
prev parent reply other threads:[~2023-06-27 7:53 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-26 23:09 [COFF] " steve jenkin
2023-06-26 23:21 ` [COFF] " Dave Horsfall
2023-06-26 23:44 ` steve jenkin
2023-06-27 21:01 ` Dave Horsfall
2023-06-26 23:32 ` Clem Cole
2023-06-27 4:43 ` Steve Jenkin
2023-06-26 23:44 ` Bakul Shah
2023-06-27 3:47 ` Steve Jenkin
2023-06-27 15:50 ` Steffen Nurpmeso
2023-06-27 16:07 ` Steffen Nurpmeso
2023-06-27 0:25 ` segaloco via COFF
2023-06-27 6:23 ` Ralph Corderoy
2023-06-27 6:28 ` Adam Thornton
2023-06-27 6:33 ` Ralph Corderoy
2023-06-27 7:53 ` steve jenkin [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=B0EDE921-CB6B-4517-B6D3-3831EF343AC9@canb.auug.org.au \
--to=sjenkin@canb.auug.org.au \
--cc=coff@tuhs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).