ultranerds has asked for the wisdom of the Perl Monks concerning the following question:

Hi,

I know this isn't really stricly perl related, but seeing as its going in a Perl script (and you guys seem to know most things :P), I thought I'd ask here =)

Basically, I'm trying to check if an image exists, before downloading it via wget. For example

http://www.test.com/something.gif

...gives a 404 status, while:

http://perlmonks.org/images/monkpics/pater_hat_sm.gif

..gives a 200.

I know its possible to do this via wget, but I can't for the life of me remember how / find the script I did it in previously.

Any suggestions?

TIA

Andy

Replies are listed 'Best First'.
Re: wget - getting status code?
by lakshmananindia (Chaplain) on May 21, 2009 at 11:17 UTC

    Refer LWP::UserAgent

    --Lakshmanan G.

    The great pleasure in my life is doing what people say you cannot do.

[reply]
      Thanks - I managed to get it working with: 

       
    # now lets actually get the image..
     my $ua = LWP::UserAgent->new;
        $ua->timeout(10);
        $ua->env_proxy;
 
     my $response = $ua->get($image);
 
     if ($response->is_success) {
        
         #print $response->content;  # or whatever

         open(WRITEIT,">$save_to") || die qq|Cant write to $save_to, r
+eason: $!|;
            binmode WRITEIT;
            print WRITEIT $response->content;
        close(WRITEIT);
         
        my ($x,$y) = imgsize($save_to);

        print qq|Got sizes: $x x $y \n|;

        return ($x,$y,$save_to_url);
        

     } else {
        # save a bad status...
         return (0,0,undef);
      }

      [download]


      (just in case anyone else comes across this issue :)

      Cheers

      Andy
[reply]
[d/l]
        Just for accuracy - I think your solution is not the real answer to the question you've asked initially.

        Probably irrelevant here, but you said you'd want to check if the image exists _before_ downloading it. In your code, you download it and _then_ check if it exists.

        If downloading is the single option, you're code is OK. But if you'd want to avoid say images bigger then 2 GiB, you're code would waste bandwide, downloading the images and then disposing them.

        To actually just check for the existence of an image, you'll want to use $ua->head($image) instead of $ua->get($image).

        Just in case that could matter.


        Krambambuli
        ---

[reply]

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