Difficulty with using LWP to display JPEG

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

Greetings Monks.

I am trying to create an HTTP request to an ordinary jpg on a website and return and print it.

Instead of an image, I am seeing what appears to be binary data. I have scoured various online websites to try and remedy this. I figured maybe it's a header issue, or perhaps I need to decode or otherwise modify the binary to some viewable format, but all has been to no avail.

Here is the code:

#!perl

use strict;
use LWP::UserAgent;
 
my $ua = LWP::UserAgent->new;
 
my $server_endpoint = "http://upload.wikimedia.org/wikipedia/en/7/70/B
+logscope-logo-simple.jpg";

my $req = HTTP::Request->new(GET => $server_endpoint);
$req->header('content-type' => 'image/jpeg');


my $resp = $ua->request($req);
if ($resp->is_success) {
    my $message = $resp->content;
    print $message;
}
[download]

I appreciate your time and help with this matter! Thanks!

Comment on Difficulty with using LWP to display JPEG Download Code

Replies are listed 'Best First'.
Re: Difficulty with using LWP to display JPEG by roboticus (Chancellor) on Apr 11, 2014 at 18:20 UTC
Aquilae: That's what I'd expect if I printed a jpeg to the console--a bunch of binary data. Instead of printing it, save it to a file: `open my $FH, '>', 'image.jpg'; binmode $FH; print $FH $resp->content; close $FH;` [download] Then use an image viewer to look at the resulting file. Update: I just replaced the contents of your if statement with the above lines of code, and tried it. It worked just fine. ...roboticus When your only tool is a hammer, all problems look like your thumb.	[reply] [d/l]
Re^2: Difficulty with using LWP to display JPEG by Aquilae (Novice) on Apr 11, 2014 at 18:26 UTC
Thank you for a quick response Roboticus. Let me explain further. What I am ultimately trying to do is make several HTTP requests to read in and print multiple images to the browser so that they appear on screen. Printing to a file will probably do me no good as I need the image to display in the browser.	[reply]
Re^3: Difficulty with using LWP to display JPEG by roboticus (Chancellor) on Apr 11, 2014 at 18:33 UTC
Aquilae: LWP lets you talk with servers over the network, it doesn't have anything to do with the browser. If you want the browser to display the images, I'd suggest one of: Use WWW::Mechanize::Firefox to drive a Firefox browser, if you're on a linux machine. Write your program in Javascript, so you can have it load the appropriate objects into a browser window. Create a website where you can direct the browser to the links you want them to see. ...roboticus When your only tool is a hammer, all problems look like your thumb.	[reply]
Re^4: Difficulty with using LWP to display JPEG by Aquilae (Novice) on Apr 11, 2014 at 19:03 UTC
Re^5: Difficulty with using LWP to display JPEG by roboticus (Chancellor) on Apr 11, 2014 at 19:14 UTC
Some notes below your chosen depth have not been shown here
Re^5: Difficulty with using LWP to display JPEG by ww (Archbishop) on Apr 12, 2014 at 17:57 UTC
Re^3: Difficulty with using LWP to display JPEG by trwww (Priest) on Apr 12, 2014 at 16:57 UTC
What I am ultimately trying to do is make several HTTP requests to read in and print multiple images to the browser so that they appear on screen. How are you calling your script? via an <img> tag in html? If thats the case, before you print the content you need to print the content type. I see this in your code: `$req->header('content-type' => 'image/jpeg');` You're setting a header in your lwp request, which is unnecessary. You should replace that line with: `print "Content-type: image/jpeg\n\n";` So you can tell the client that requested your script's output the content type of the output it will receive. Although without more information it seems like it would make sense to just have your image pull right from the remote server: `<img src="http://upload.wikimedia.org/wikipedia/en/7/70/Blogscope-logo-simple.jpg" />`	[reply] [d/l] [select]