Re Perl's read speed, it's faster when not doing the line number check for
every line. So `perl -ne 'print if (/pattern/)'` is only ~2.60s, compared
to ~3.28s for `perl -ne 'print if ($. == 1 || /pattern/)'`. Doing nothing
in Perl, i.e., `perl -ne ''` is only ~1.38s.
Dan
On Wed, Aug 23, 2023 at 6
On the original test machine I timed the sed solution, as well as `(grep
-m1 . 'file' && grep 'pattern' 'file')` and `(mapfile -n1 <'file' && echo
$MAPFILE[0] && grep 'pattern' 'file')` and `(head -n1 'file' && grep
'pattern' 'file')`. Total table of speeds.
grep (v2.20):~1.15s
perl (
7;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 wrote:
>
> > That works, as well as the Perl version I've been using:
> &
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 wrote:
> Daniel Green wrote:
>
> > I'm frequently searching CSV files with 20-30 columns, and when there&#x
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
