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

I've read over a few posts concerning uploading files and I am looking at pp152-5 in Lincoln Stein's book on using cgi.pm. Right now, I am just toying around with uploading a file from the local hard drive to the server. All I am doing in my current script is is uploading the file and then trying to print its contents to the web browser window. However, instead of the file's contents, I am just getting the file's name.

## cgi.pm parameters
use CGI;
#use CGI::Carp qw(fatalsToBrowser carpout);
$CGI::DISABLE_UPLOADS = 0;
$CGI::POST_MAX = 24000;
my $query = new CGI;
$query = CGI->new();

my %formdata;
my @formfields = $query->param;

for my $field(@formfields) {
  $formdata{$field} = $query->param($field);
}

print <<FORM;
<center>
<form method="post" action="https://www.$domain/$self" enctype="multip
+art/form-data">
<input type="hidden" name="mod" value="on">
<input type="file" name="upload"  size="40"><p>
<input type="image" src="$images/submitbutton.gif">
</form>
</center>
FORM

## end upload documents ##

while(<$formdata{upload}>) {
  print;
}

[download]

This is just a snippet of my code. It seems to upload the file, however when a user selects C:\somefile.txt, the while statement just prints out this same path, minus the backslash. Based on Mr. Stein's code on p153 of his book with an example of how to print a file out to a local file on the server, I had thought the above snippet would work.

Can someone please point me straight?

humbly -c

Replies are listed 'Best First'.
Re: Uploading files using cgi.pm
by AidanLee (Chaplain) on Nov 29, 2001 at 19:39 UTC

    You might investigate the upload() function. From the CGI docs:

         $fh = $query->upload('uploaded_file');
     while (<$fh>) {
           print;
     }

    [download]
[reply]
[d/l]
      I read through CGI.pm and see what you are referring to. The doc says that $fh will return a usable filehandle or undef if the param is not a valid filehandle.

      I changed my existing code to reflect your suggestion, however I kept my loop in place that stick forms values into a hash. So, I ended up with something like:

      my $fh = $query->upload($formdata{upload});

      [download]

      This ended up coming back as undef, however once I removed my hash and made a direct query:

      my $fh = $query->upload('upload');

      [download]

      it worked. Thanks for your help.

      -c

[reply]
[d/l]
[select]
Re: Uploading files using cgi.pm
by cfreak (Chaplain) on Nov 29, 2001 at 22:17 UTC
    You don't need a filehandle, rather you need to use the read statement. So rather than what you have here: 
    while(<$formdata{upload}>) {
  print;
}

    [download]

    Change that to: 
    my $buffer;
while(read $formdata{upload},$buffer,1024) {
     print $buffer;
}

    [download]

    you can also limit the size of the image being uploaded: 
    my $buffer;
my $max_size = 10 * 1024; # 10 KB but it can be whatever
my $size;
while(read $formdata{upload},$buffer,1024) {
     $size += 1024;
     if($size > $max_size) {
          print "Image is too big!";
          last;
     }
}

    [download]
[reply]
[d/l]
[select]
Re: Uploading files using cgi.pm
by cLive ;-) (Prior) on Nov 30, 2001 at 01:04 UTC
    Hmmm,

    When I get stuck I like to look through the Q & A section of the monastry. In this case I'd probably look through the CGI Programming section and look for the word 'upload'. This word then point me to How can I get started with a file upload script?.

    But that's just me, I suppose.

    cLive ;-)

    note - I have a stinking cold and sarcasm is as good as a hot toddy when I feel this groggy... ;-)

[reply]
      I did take a look at that :) but i'm only interested in uploading text files, and I don't think I'll need to touch binmode. Maybe that should be renamed "How should I get started with an image upload script?".

      humbly -c

[reply]

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