URI::Escape::escape_char error when posting to a form inside perl script

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

I've used this code on my website for years without issue. Recently, it appears that my host upgraded the shared hosting server that I use and now I receive an error Undefined subroutine &URI::Escape::escape_char called at /usr/local/share/perl/5.10.1/URI/_query.pm line 51. This occurs when I post a form in perl. I realize that scalars I'm posting have characters that are reserved in URI even though this worked before, so I tried using uri_escape() to no avail. I've spent 10 hours or so now trying to figure this out. I am out of ideas and need your wisdom!

#!/usr/bin/perl

use strict;
use LWP::UserAgent;
use HTTP::Request::Common;

my $URLtoPostTo = "http://www.theurltopostto.com";
my %Fields = (
   "data1" => "$email",
   "data2" => "$somethingelse",
   "data3" => "$andanother"
);

my $BrowserName = "This Be Mine";

my $Browser = new LWP::UserAgent;

if($BrowserName) { $Browser->agent($BrowserName); }

my $Page = $Browser->request(POST $URLtoPostTo,\%Fields);

#I don't need the results data
[download]

Comment on URI::Escape::escape_char error when posting to a form inside perl script Download Code

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Re: URI::Escape::escape_char error when posting to a form inside perl script by kcott (Archbishop) on Jan 31, 2013 at 05:59 UTC
G'day marknher, Welcome to the monastery. According to the HTTP::Request::Common documentation, the `request()` method, when used with `POST`, takes its list of key-value pairs as an arrayref: `use HTTP::Request::Common; $ua = LWP::UserAgent->new; $ua->request(POST 'http://somewhere/foo', [foo => bar, bar => foo]);` [download] You're using a hashref (`\%Fields`). I'd suggest changing your `request()` call to: `my $Page = $Browser->request(POST $URLtoPostTo, [%Fields]);` [download] -- Ken	[reply] [d/l] [select]
Re^2: URI::Escape::escape_char error when posting to a form inside perl script by marknher (Initiate) on Jan 31, 2013 at 06:15 UTC
Thank you Ken, I've updated my code to include [] around %fields. Unfortunately, the error remains. From what I can tell, it's because the scalars in the pairs have reserved characters such as @, etc. Any other ideas? Thanks, Mark T.	[reply]
Re^3: URI::Escape::escape_char error when posting to a form inside perl script by kcott (Archbishop) on Jan 31, 2013 at 06:56 UTC
Take a look at the code for `URI::Escape` which you'll probably find at `/usr/local/share/perl/5.10.1/URI/Escape.pm`. In the current source for this module, `escape_char()` is coded right at the end: `... sub escape_char { return join '', @URI::Escape::escapes{$_[0] =~ /(\C)/g}; } 1;` [download] If it's not there, you'll need to ask your server administrators to update their code. If it is there, please show the actual code you are running, i.e. with the calls to `uri_escape()` - the problem may lie with your implementation. -- Ken	[reply] [d/l] [select]
Re^4: URI::Escape::escape_char error when posting to a form inside perl script by Anonymous Monk on Jan 31, 2013 at 09:40 UTC
Re^3: URI::Escape::escape_char error when posting to a form inside perl script by marknher (Initiate) on Jan 31, 2013 at 06:24 UTC
If I comment out one of the key-pairs that have a reserved character such as $email (which has @ in it) then the script works fine. Thanks, Mark	[reply]
Re: URI::Escape::escape_char error when posting to a form inside perl script by Anonymous Monk on Jan 31, 2013 at 05:58 UTC
install URI::Escape, upgrade LWP and all the prerequisites	[reply]
Re^2: URI::Escape::escape_char error when posting to a form inside perl script by marknher (Initiate) on Jan 31, 2013 at 06:12 UTC
Unfortunately, since this is shared hosting server I'm unable to install or update anything on it. However, I'm not sure, but I'm assuming since I get an error regarding URI:Escape wouldn't that mean that some version is already installed? Thanks, Mark T.	[reply]
Re^3: URI::Escape::escape_char error when posting to a form inside perl script by Anonymous Monk on Jan 31, 2013 at 08:23 UTC
No `$ perl -we " URI::Escape::escape_char() " Undefined subroutine &URI::Escape::escape_char called at -e line 1. $ perl -we " use URI::Escape; URI::Escape::escape_char(1) "` [download] Since you get that from URI/_query.pm it must mean your URI installation is incomplete/broken -- install latest is solution :) Oh, and see Yes, even you can use CPAN Top 11 (GOOD) reasons not to use someone else's Modules, Top Seven (Bad) Reasons Not To Use Modules	[reply] [d/l]
Re: URI::Escape::escape_char error when posting to a form inside perl script by Khen1950fx (Canon) on Jan 31, 2013 at 07:26 UTC
I would try it like this: `#!/usr/bin/perl use strict; use warnings; use LWP::UserAgent; use HTTP::Request::Common qw/POST/; my(@fields) = ( 'http://your.url.com', [ data1 => 'something', data2 => 'somethingelse', data3 => 'andanother' ] ); my $ua = LWP::UserAgent->new; my $req = POST @fields; print $ua->request($req)->as_string();` [download]	[reply] [d/l]
Re: URI::Escape::escape_char error when posting to a form inside perl script by Anonymous Monk on Jan 31, 2013 at 23:32 UTC
In my all night (again) of searching I finally found a workaround that solved my issue since the host admin was of no help. In case, this comes up in the future for anyone.. Thank you monks for your help. I was literally lost for days and dreaming about this crap. `use strict; use LWP::UserAgent; use HTTP::Request::Common; my $data1 = "$something"; my $data2 = "someone@email.com; my $data3 = "something"; my $prepstring = "data1=$data1\&data2=$data2\&data3=$data3"; my $ua = LWP::UserAgent->new(); my $response = $ua->post("$URLtoPostTo", Content => $preppedstring ); # This allows reserved characters such as @$ to pass through URI:Escap +e without issue I guess.` [download]	[reply] [d/l]


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