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

I am trying to run some information off of a web site. The code that I had been using is as below. 
   #!/usr/bin/perl -w
   use strict;
   use LWP::Simple;
   my @a = get("http://www.thewolfweb.com/");
   print "@a";

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The above works fine. When I change the 4th line to 
   my @a = get("http://www.thewolfweb.com/message.asp\?section\=6");

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I get a use of uninitialized variable on line 5. I was curious as to what this could be.

Also if anyone is familiar with this, I might need to login somehow or represent my user ID by showing a cookie. Could this cause the error? If so or if not could someone tell me how this could be done. I don't know what module to use if I do try to do this.

Thanks much in advance.

LeGo

Replies are listed 'Best First'.
Re: lwp::simple basic question about webbing
by ichimunki (Priest) on Jan 18, 2001 at 00:15 UTC
    In addition to following merlyn's advice about switching to a different module, I'd suggest using something like 
    my $a = get( $url ) || "get $url failed";

or

my $a = get( $url ) or die "Couldn't get() $url: $!";

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    The scalar is probably better to assign a blob of text info to. With the || operator, your variable is guaranteed to at least contain something-- if not the HTML, then an error message (since if get fails, it returns undefined). With the "die" message, your program stops altogether with an informative message-- probably better unless dying is not at all an option.
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Re: lwp::simple basic question about webbing
by merlyn (Sage) on Jan 18, 2001 at 00:05 UTC
    That page needs authorization. LWP::Simple isn't that smart. You'll need to read about how to provide authorization using LWP::UserAgent.

    -- Randal L. Schwartz, Perl hacker

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      This might not be directly to you merlyn but maybe a general question. I have a real hard time reading perl directions :). I did notice that my cookies file had been added to by the website I am trying to use. So I would like to somehow show this up to the server I am going into. I noticed this as possibly what I need to use but don't understand how. This is a part of LWP::UserAgent

      $ua->cookie_jar([$cookies])

      Get/set the HTTP::Cookies object to use. The default is to have no cookie_jar, i.e. never automatically add "Cookie" headers to the requests.

      I have four lines of stuff from this website. Would I put them into an array, would I put the cookies in $cookies and have many of the above lines of code, or how might I go about showing them my cookies that the have set?

      LeGo

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        If you are using Netscape, you can use HTTP::Cookies to have your LWP::UserAgent client read and write from your actual Netscape cookie files without needing to cut and paste the cookie string into your code:

        #!/usr/bin/perl -w

use strict;
use HTTP::Cookies;
use LWP::UserAgent;

#Set path to your Netscape Cookie files
my $cookie_jar = HTTP::Cookies::Netscape->new(
  File     => "$ENV{HOME}/.netscape/cookies",
  AutoSave => 1,
);

#Create a User Agent, and tell it to store cookies
my $ua = LWP::UserAgent->new;
$ua->cookie_jar($cookie_jar);
#...

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        If you aren't using Netscape, then you will have to explicitly set the cookies in the $cookie_jar object, which you can do using the HTTP::Cookies::set_cookie() method.

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