in reply to Automated extraction of NOAA weather satellite images

I had never heard of Time::Tiny before... If I understand its man page correctly, I think your code would create variable-length file names that might be hard to interpret reliably -- and might not be unique over the course of a day. That is, when you do: 
my $timestring = $current_time->hour.$current_time->minute.$current_ti
+me->second;

[download]
the time-stamp portion of each file name will range from "*.000.jpg" at midnight to "*.235959.jpg" at one second before midnight, with potential file-name collisions among sets of times like 01:23:45, 12:03:45 and 12:34:05 (which all would end up as "*.12345.jpg"), for example.

Personally, I'd use the POSIX "strftime" function to set up fixed-width (zero-padded) strings for the file names -- and while I'm at it, might as well throw in the "ymd" date as well. Also, I think I'd rather use less repetition in the literal strings (looks like there was an inconsistency in your file names: an extra "v" in "westconusvwv"). 

use strict;
use LWP::Simple;
use POSIX;

my %image_url;
for my $e_w ( qw/eastconus westconus/ ) {
    for my $typ ( qw/ir vs wv/ ) {
        $image_url{$e_w.$typ} = "http://www.goes.noaa.gov/GIFS/" .
             uc(substr($e_w,0,1)) . 'C' . $typ . '.JPG';
    }
}
my $timestring = strftime( "%Y%m%d_%H%M%S", localtime );
print $timestring;

for my $img ( keys %image_url ) {
    my $status = getstore( $image_url{$img}, join( '.', $img, $timestr
+ing, 'jpg' ));
    print join( "\n", $img, $image_url{$img}, $status, "\n" );
}

[download]
For that matter, it would be even simpler if I decided that the original four-letter NOAA file names were good enough for me...

(updated the code to add a missing close-paren at line 16. Thanks, zentara!)

Replies are listed 'Best First'.
Re^2: Automated extraction of NOAA weather satellite images
by Scott7477 (Chaplain) on May 30, 2007 at 13:51 UTC
    Thanks for the feedback. I was looking at the POSIX module for including a timestamp in the saved filenames, but wanted to get a script up and running quickly and having never used the "strftime" function you mention Time::Tiny filled the bill. I agree with the potential problems you point out that the timestamps in my code have... I have updated my code to use the "strftime" function and the filenames now are very precise(for example "eastconusir20070530_074348.jpg"): 
    #NOAA updates the images on the GOES website every 30 minutes

use strict;
use LWP::Simple;
use POSIX;


my $image;
my $url;
my %images = (
 "eastconusir"  => "http://www.goes.noaa.gov/GIFS/ECIR.JPG",
 "eastconusvis" => "http://www.goes.noaa.gov/GIFS/ECVS.JPG",
 "eastconuswv"  => "http://www.goes.noaa.gov/GIFS/ECWV.JPG",
 "westconusir"  => "http://www.goes.noaa.gov/GIFS/WCIR.JPG",
 "westconusvis" => "http://www.goes.noaa.gov/GIFS/WCVS.JPG",
 "westconusvwv" => "http://www.goes.noaa.gov/GIFS/WCWV.JPG",
        );

my $timestring = strftime( "%Y%m%d_%H%M%S", localtime );
print $timestring."\n";

foreach my $key (keys %images) {
    print $key."\n";
    print $images{$key}."\n";
    my $status = getstore($images{$key},$key.$timestring.".jpg");
        print $status."\n" ;
    };

    [download]


    See my Standard Code Disclaimer
[reply]
[d/l]

In Section Cool Uses for Perl