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

I need to "pack" a URL into a URL as one of the parameters to a script. For example: 

http://cgi3.ebay.com/aw-cgi/eBayISAPI.dll?MfcISAPICommand=SignInWelcom
+e&userid=userid&pass=pass&keepMeSignInOption=1&ru=http%3A%2F%2Fcontac
+t.ebay.com%2Faw-cgi%2FeBayISAPI.dll%3FReturnUserEmail%26requested%3Du
+ser%26de%3Doff%26iid%3D1733367971%26frm%3D284%26acceptcookie%3D1%26lo
+ginconfirmed%3D1%26pass%3D%7B_pass_%7D%26userid%3D

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If you look deep into the URL, you see the parameter "ru". That parameter has to be an encoded url.

I know that string as a literal would work fine.

So what's my problem?

I want the "ru" parameter as a separate, readable string in perl, so developers don't kick themselves when they look at my uncommented.

Code: 
$main_request = "http://cgi3.ebay.com/aw-cgi/eBayISAPI.dll?MfcISAPICom
+mand=SignInWelcome&userid=userid&pass=pass&keepMeSignInOption=1&ru=";
$ru = "http://encode_this/";
# Encode $ru ?????
$main_request += $ru;

# Send $main_request

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Thanks for the help.

-Keith

Replies are listed 'Best First'.
•Re: Packing a URL into a URL
by merlyn (Sage) on May 29, 2002 at 03:34 UTC
    Just use URI as it was intended: 
    $main = 'http://cgi3.ebay.com/aw-cgi/eBayISAPI.dll'; 
$ru = "http://encode_this/";
use URI;
my $uri = URI->new($main);
$uri->query_form(
  qw(MfcISAPICommand SignInWelcome userid userid pass pass keepMeSignI
+nOption 1),
  ru => $ru
 );
print $uri->as_string;

    [download]
    which generates 
    http://cgi3.ebay.com/aw-cgi/eBayISAPI.dll?MfcISAPICommand=SignInWelcom
+e&userid=userid&pass=pass&keepMeSignInOption=1&ru=http%3A%2F%2Fencode
+_this%2F

    [download]

    -- Randal L. Schwartz, Perl hacker

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[d/l]
[select]
Re: Packing a URL into a URL
by Zaxo (Archbishop) on May 29, 2002 at 02:30 UTC
    Here you go
    #!/usr/bin/perl -w
use strict;

use URI::Escape;
use HTTP::Request;

my $ru = uri_escape("http://foo.org/cgi-bin/bar.cgi?baz = qu ux;foo=di
+m");

my $v=new HTTP::Request(url=>"http://foo.org/cgi-bin/bar.cgi?ru=$ru");
print $v->url, $/;

=pod

prints:
http://foo.org/cgi-bin/bar.cgi?ru=http%3A%2F%2Ffoo.org%2Fcgi-bin%2Fbar
+.cgi%3Fbaz%20%3D%20qu%20ux%3Bfoo%3Ddim

call, say:
$cgi->redirect( uri_unescape($cgi->param('ru'));
to use the url
=cut

    [download]

    Update: I hasten to point out the the uri_unescape() suggestion in pod is insecure if you care where the redirect goes or whether it is an url at all. Repaired a couple of pasteos.

    After Compline,
    Zaxo

[reply]
[d/l]
      Zaxo, I compiled your code to the up until the "=pod" line. You say: 
      prints:
http://foo.org/cgi-bin/bar.cgi?ru=http%3A%2F%2Ffoo.org%2Fcgi-bin%2Fbar
+.cgi%3Fbaz%20%3D%20qu%20ux%3Bfoo%3Ddim

      [download]

      But, this is what it prints on my machine: 
      http://foo.org/cgi-bin/bar.cgi?ru=http://foo.org/cgi-bin/bar.cgi?baz%2
+0=%20qu%20ux;foo=dim

      [download]

      Only spaces are encoded.........?
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[d/l]
[select]

      Not sure why you're getting different results, but I can tell you hoe to adjust what gets escaped. &uri_escape can take a second argument, a string which specifies a character class to escape. "^A-Za-z" will escape everything but ASCII alphabetics.

      From the command line mine does ( with versions):

      $ perl -MURI::Escape -MHTTP::Request -e'my $ru=uri_escape("http://foo.
+org/cgi-bin/bar.cgi?baz = qu ux;foo=dim");$v=new HTTP::Request(url=>"
+http://foo.org/cgi-bin/bar.cgi?ru=$ru");print $v->url,$/,"URI::Escape
+ v",$URI::Escape::VERSION,$/,"Perl v",$],$/'
http://foo.org/cgi-bin/bar.cgi?ru=http%3A%2F%2Ffoo.org%2Fcgi-bin%2Fbar
+.cgi%3Fbaz%20%3D%20qu%20ux%3Bfoo%3Ddim
URI::Escape v3.20
Perl v5.006001
$

      [download]
      on Linux. I wonder if the difference is in defaults selected at build?

      After Compline,
      Zaxo

[reply]
[d/l]

        The results are different because of different versions of URI::Escape.

          Jenda

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