Re: [gentoo-user] OT: Extracting year from data, but honour empty lines

[Floyd Anderson]

Hi Daniel,

On Fri, 11 May 2018 16:16:52 -0700
Daniel Frey <djqfrey@×××××.com> wrote:
>
> […]
>
>Does anyone have a quick tip for my tired brain to make this work and
>just output a blank line if there's no match? I swear I did this months
>ago and had something working but I apparently didn't bother saving the
>script I made. Argh!

if you can ensure there is only one four-digit year per line, try to 
strip all other line characters with:

    $ sed -e 's/.*\([0-9]\{4\}\).*/\1/' /path/to/your-date-file

while keeping none matching lines as they are. Note, pattern is always 
greedy and picks up the last year it founds.


-- 
Regards,
floyd