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From: Ralph Corderoy <ralph@inputplus.co.uk>
To: coff@tuhs.org
Subject: [COFF] Re: Shell script advice: using 'dd' to write multiple media
Date: Tue, 27 Jun 2023 07:23:16 +0100	[thread overview]
Message-ID: <20230627062316.858C6220E5@orac.inputplus.co.uk> (raw)
In-Reply-To: <D0AEA7F2-9981-4AAF-8F52-3FCF79089394@canb.auug.org.au>

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.

  parent reply	other threads:[~2023-06-27  6:23 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 [this message]
2023-06-27  6:28   ` Adam Thornton
2023-06-27  6:33     ` Ralph Corderoy
2023-06-27  7:53   ` steve jenkin

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