LWP+cgi file upload problems

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

ok so I've spent the last 2 days in the twilight zone. I cannot get something straight-forward to work. Please help.

I want to upload files to a web site using a script. The site has a html + CGI script that are able to successfully upload a file when using a web browser. Give it a try on http://www.perfectotion.co.uk/upload4s.html.

I am trying to get the SAME thing working using the LWP::UserAgent;. There are plenty of examples about and I?ve closely followed an example from lwpcook.

The client I?m running on is win2000 + Activeperl5.6. The server is a commercial server running solaris+apache.

I?ve given the various scripts below. I need to explain one thing that is a separate problem with the upload4s.cgi script.

PROBLEM(1)I couldn?t get the traditional upload script to work i.e

my $file = $q->param("file") || error ($q, " No file received.");
my $filename = $q->param("filename") || error ($q, " No filename enter
+ed.");

my $fh = $q->upload( $file );

$tmp="../user/$filename";
open(OUTPUT, ">$tmp") or die ("Cannot open upload file"); 
while ( read( $fh, $buffer, 1024) ) { 
    print OUTPUT $buffer; 
}
[download]

what seems to happen is the temp file opened by $fh receives the data but the while loop never does anything so ../user/$filename is created but zero length.

The workaround is to access the temp file directly. I?ve used a call to unsupported CGI.pm method tmpFileName() to give me the tmp file name. I then read this and write out to the final output file. Seems to work well but only from a browser dialog. No joy with LWP::UserAgent. It would seem that I?m not formatting the file post from uper.pl but I cannot find out what?s wrong. The theory is that if it works from a browser it should work from the LWP script provided it's formatted properly.

So here are the various scripts

 ****************** Upload4s.cgi

#!/usr/bin/perl -- 
$|=1; #Switch off buffering. 

use CGI qw( :standard );
use Fcntl qw( :DEFAULT :flock);

use constant UPLOAD_DIR => '../user';
use constant BUFFER_SIZE => 16_384;
use constant MAX_FILE_SIZE => 1_048_576;
use constant MAX_DIR_SIZE => 100 * 1_048_576;
use constant MAX_OPEN_TRIES => 2;

$CGI::DISABLE_UPLOADS = 0;
$CGI::POST_MAX = MAX_FILE_SIZE;

my $q = new CGI;
print $q->header, $q->start_html, $q->Dump;

$q->cgi_error and error( $q, "Error transferring file: " . $q->cgi_err
+or );

my $file = $q->param("file") || error ($q, " No file received.");
my $filename = $q->param("filename") || error ($q, " No filename enter
+ed.");
my $buffer = "";
$tmp="../user/$filename";
open(OUTPUT, ">$tmp") or die ("Cannot open upload file");
binmode OUTPUT;
open(FH,$q->tmpFileName($file)) or die ("eeeek dead");

while (read( FH, $buffer, 1024) ) { #FH
    print OUTPUT $buffer; 
}

close OUTPUT;
close FH;
[download]

**************** upload4s.html

<html>
<head>
<title>Untitled Document</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1
+">
</head>

<body bgcolor="#FFFFFF">
<form action="upload4s.cgi" method="POST" enctype="multipart/form-data
+">
  <p>Please choose a file to upload: 
    <input type="FILE" name="file">
  <p>Please enter the name of this file: 
    <input type="TEXT" name="filename">
</form>
<p>&nbsp;</p></body>
</html>
[download]

***************** uper.pl ? DOESN?T WORK ? run on Win2000.

#!/perl/bin/perl
  use HTTP::Request::Common qw(POST);
  use LWP::UserAgent;
  use LWP::Debug qw(+);

  my $ua = new LWP::UserAgent;  

  my $req = POST 'http://www.perfectmotion.co.uk/upload4s.cgi',
               [ filename => '111', file => 'C:\test.bat? ];
               
           #    print $req;
               
             
 my $res = $ua->request($req);
  print $res->as_string;
[download]

Comment on LWP+cgi file upload problems Select or Download Code

Replies are listed 'Best First'.
Re: LWP+cgi file upload problems by chromatic (Archbishop) on Jul 14, 2001 at 08:21 UTC
You might need to specify multipart/form-data encoding in your LWP program: `my $req = POST 'http://www.perfectmotion.co.uk/upload4s.cgi', [ 'c:\test.bat', '111', Content-type => 'multipart/form-data' ];` [download] This is untested. See HTTP::Request::Common for more details.	[reply] [d/l]
Re: LWP+cgi file upload problems by wertert (Sexton) on Jul 11, 2001 at 01:19 UTC
sorry that should be http://www.perfectmotion.co.uk/upload4s.html	[reply]