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bug#65416: Feature request: include first line of file in output
From: |
arnold |
Subject: |
bug#65416: Feature request: include first line of file in output |
Date: |
Mon, 21 Aug 2023 12:37:12 -0600 |
User-agent: |
Heirloom mailx 12.5 7/5/10 |
Gawk 4.0.2 is 11 years old. Try timing the current version,
I'll bet it's faster. And it solves your problem NOW,
instead of waiting for a feature that the grep developers
aren't likely to add.
My two cents of course.
Arnold
Daniel Green <ddgreen@gmail.com> wrote:
> That works, as well as the Perl version I've been using:
>
> perl -ne 'print if ($. == 1 || /pattern/)'
>
> But timings for a real-life example (3GB file with ~16m lines, CentOS 7)
> show the problem:
>
> grep (v2.20): ~1.15s
> perl (v5.36.1): ~4.48s
> awk (v4.0.2): ~10.81s
>
> Admittedly grep is just searching in those timings, but I suspect it could
> accomplish the full task with a minimal decrease in speed.
>
> Dan
>
> On Mon, Aug 21, 2023 at 12:57 PM <arnold@skeeve.com> wrote:
>
> > Daniel Green <ddgreen@gmail.com> wrote:
> >
> > > I'm frequently searching CSV files with 20-30 columns, and when there's a
> > > hit it can be hard to know what the columns are. An option to also print
> > > the first line of a file (either always, or only if that file had a match
> > > to the pattern) in addition to any hits would be nice.
> > >
> > > Thanks,
> > > Dan
> >
> > It sounds like awk would be a better tool:
> >
> > awk 'FNR == 1 || /pattern/' files ...
> >
> > should do the trick.
> >
> > HTH,
> >
> > Arnold
> >
- bug#65416: Feature request: include first line of file in output, Daniel Green, 2023/08/21
- bug#65416: Feature request: include first line of file in output, arnold, 2023/08/21
- bug#65416: Feature request: include first line of file in output, Daniel Green, 2023/08/21
- bug#65416: Feature request: include first line of file in output, Paul Jackson, 2023/08/23
- bug#65416: Feature request: include first line of file in output, Paul Jackson, 2023/08/23
- bug#65416: Feature request: include first line of file in output, Daniel Green, 2023/08/23
- bug#65416: Feature request: include first line of file in output, Paul Jackson, 2023/08/23
- bug#65416: Feature request: include first line of file in output, Daniel Green, 2023/08/24
- bug#65416: Feature request: include first line of file in output, lacsaP Patatetom, 2023/08/29