Re: Looking for regex

It worked!

I'll have to digest what you did, this evening. It's been raining for over a week and the sun is finally out so, I have to take care of some yard work.

Thanks again, Chas!

T

"Chas. Owens" <chas.owens@xxxxxxxxx> wrote:
On Jan 26, 2008 1:13 PM, John Kufrovich wrote:
Chas,
Thanks for the help. I'm not expert but I think your code will output each
line.
snip

You don't have to be an expert to run the code and see what it does
(it only prints out the hour and temp for the first instance of each
hour). If you want to print out the whole line for the first instance
of each hour you can simplify the regex and the print:

#! /usr/bin/perl

use strict;
use warnings;

my %seen;
while () {
my ($hour) = / (..)/;
print unless $seen{$hour}++;
}

__DATA__
2007-01-23 00:01:00,43.3,34.9,30.14,North,359,7,8,72,0.00,,,0.00,Wunderground
v.1.13,
2007-01-23 00:06:00,43.2,34.8,30.14,North,354,11,11,72,0.00,,,0.00,Wunderground
v.1.13,
2007-01-23 00:12:00,43.2,34.8,30.14,North,1,6,9,72,0.00,,,0.00,Wunderground
v.1.13,
2007-01-23 01:11:00,42.9,34.8,30.13,North,1,5,6,73,0.00,,,0.00,Wunderground
v.1.13,
2007-01-23 01:17:00,42.9,34.8,30.12,NNW,346,3,7,73,0.00,,,0.00,Wunderground
v.1.13,
2007-01-23 01:23:00,43.1,35.0,30.12,North,359,5,11,73,0.00,,,0.00,Wunderground
v.1.13,
2007-01-23 02:14:00,43.2,34.1,30.10,North,0,16,16,70,0.00,,,0.00,Wunderground
v.1.13,
2007-01-23 02:19:00,43.2,34.1,30.09,North,0,6,13,70,0.00,,,0.00,Wunderground
v.1.13,
2007-01-23 02:24:00,43.2,33.7,30.09,North,349,8,14,69,0.00,,,0.00,Wunderground
v.1.13,
2007-01-23 03:04:00,43.2,34.1,30.11,North,0,7,12,70,0.00,,,0.00,Wunderground
v.1.13,
2007-01-23 03:09:00,43.2,34.1,30.11,North,0,10,17,70,0.00,,,0.00,Wunderground
v.1.13,

This can be further refined into a single command:

perl -ne '($h)=/ (..)/;print unless $s{$h}++' file_to_filter