On 2022-12-20 at 05:37, David wrote: > On Tue, 20 Dec 2022 at 21:10, The Wanderer <wande...@fastmail.fm> > wrote: > >> On 2022-12-20 at 02:51, Thomas Schmitt wrote:
>>> This contradicts the promises of man grep about option -m.
>>
>> It does seem to, at least at a glance - but I think I've figured
>> out what's going on, and it's actually consistent with the option
>> set you gave.
>
> [...]
>
> Hi,
>
> Slightly offtopic rambling ...
>
> I haven't looked at the 'grep' part of the above expression, but
> I assume that its output lines look something like:
> 100:CD001
>
> If that is the case, then awk does not need any assistance
> from 'expr' or 'sed' (and even not from 'grep' if we were not
> searching a binary file).
>
> Short demo:
> $ echo 100:CD001 | awk 'BEGIN { FS=":" } /CD001/ { print $1 - 50 }'
> 50
If you replace the "echo 100:CD001" with "echo -e
'100:CD001\n200:CD001'" (not sure if that syntax is portable to all
shells, but it works in my version of bash), this does print '50' and
'150' on consecutive lines - which (if I'm not mistaken) matches the
behavior of the original pipeline, but is not what is actually desired
here.
> I only write this because I just magine how poor old 'awk' feels:
> "don't embed me in this pipelines and subshells and unnecessary
> commands, I can do all that stuff myself without any help!!".
Because of the above, it looks like a pipeline may still be necessary
here, to filter it down to just the first number being output. Unless
awk has another feature that would let us do that limiting internally too?
--
The Wanderer
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore all
progress depends on the unreasonable man. -- George Bernard Shaw
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