frinky, the limitation that you have run into is one of the many reasons why people recommend that you use CGI.pm or one of its (few) competitors on the CPAN. Your code cannot handle file uploads and is unlikely to be able to do so at any point in the future. This is because the encoding for 'multipart/form-data' is much different from the standard encoding that you are used to. Lets look at a standard upload form.

<form action="/cgi-bin/display.cgi" method="post" enctype="multipart/f
+orm-data">
    <input type="file"     name="file" /><br />
    <input type="hidden"   name="hiddenData"   value="nothing to see h
+ere, folks" /><br />
    <input type="checkbox" name="someCheckbox" value="someValue" check
+ed="checked" />Checkbox<br />
    <input type="submit"><br />
</form>
[download]

Let's say that I use that form to upload a small file named 'temp.pl'. The entity-body (the part after the headers) that is sent to the browser might resemble the following:

-----------------------------7d03ca41c0
Content-Disposition: form-data; name="file"; filename="C:\WINDOWS\Desk
+top\temp.pl"
Content-Type: text/plain

#!C:/perl/bin/perl.exe -w
use strict;

$SIG{INT} = 'IGNORE';
my $count=0;
while (){
    print $count++;
}


-----------------------------7d03ca41c0
Content-Disposition: form-data; name="hiddenData"

nothing to see here, folks
-----------------------------7d03ca41c0
Content-Disposition: form-data; name="someCheckbox"

someValue
-----------------------------7d03ca41c0--
[download]

Not only is that rather difficult to parse, but different browsers often have subtly different formats for multipart/form-data. Debugging those issues can be a nightmare. That is one of the many reasons people suggest that you use a standard module instead of trying to roll your own.

Since CGI.pm is part of the standard distribution, you should have no problem using it. Check out Lesson 2 of my CGI course for more information about this topic.

Cheers,
Ovid

Join the Perlmonks Setiathome Group or just click on the the link and check out our stats.

You don't say why you didn't use a single module. If it's an exercise in "can I do this", then pat yourself on the back and move on. For production code, CGI.pm is a more responsible^* thing to use, and it's included in all modern Perl distributions, so your chances of not encountering it are effectively nil.

* There are numerous subtle security problems that crop up if you try to handle CGI requests by hand. CGI.pm handles them, and it's been thoroughly tested.

Of course, people that do that will have to license their script under the same license as CGI.pm if they distribute it.

-sam

-sam

sub library_read_form {
 # Reads the incoming data from the web browser
 my ($buffer,$pair,$datasent,$name,$value,$mydata,$filename,$contentty
+pe)=("","","","","","","","");
 if (length($ENV{'CONTENT_LENGTH'})>0) {
  if ($ENV{'CONTENT_TYPE'}=~/^multipart\/form-data/i) {
   binmode(STDIN); # cope with Windows platforms - but only if we have
+ to...
  }
  read(STDIN, $buffer, $ENV{'CONTENT_LENGTH'});
  if (length($ENV{'QUERY_STRING'}>0)) { $buffer.="&".$ENV{'QUERY_STRIN
+G'};}
 } else {
  $buffer=$ENV{'QUERY_STRING'};
 }
 foreach $var (sort(keys(%ENV))) {
  $val = $ENV{$var};$val =~ s|\n|\\n|g;$val =~ s|"|\\"|g;
 }
 if (($buffer=~/^\<doc /) && ($buffer=~/\<\/doc\>\n?$/)) {
  ### section removed.....
  ### don't ask what this did or why, I'm not allowed to say :(
 } else {
  if (!($ENV{'CONTENT_TYPE'}=~/^multipart\/form-data/i)) {
   @pairs = split(/(&|;)/, $buffer);
   foreach $pair (@pairs) {
    ($name, $value) = split(/=/, $pair);
    $value =~ tr/+/ /;
    $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
    $datasent.=";$name=$value";
    if (length($form{$name})>0) { $value=$form{$name}."\0".$value; }
    $form{lc($name)} = $value;
   }
  } else {
   $ENV{'CONTENT_TYPE'}=~/boundary=([^"]+)/i;
   $boundary="--".$1;$section=0;
   @lines=split(/(\n|\r)/,$buffer);
   MULTIPART: foreach $line (@lines) {
    if ($section==3) { 
     if ($line=~/content-type:\s?(.*)/i) {
      $contenttype=$1;
     } elsif (!($line=~/^(\n|\r|\n\r|\r\n)?$/)) {
      $section=4;
     }
    } elsif ($section==2) {
      if ($line=~/^content-type:\s?(.*)/i) {
      $contenttype=$1;
     } elsif ($line=~/^(\n|\r|\n\r|\r\n)?$/) {
      $section=3; # data possibly starts next line
     }
    } elsif ($section==1) {
       if ($line=~/^content-disposition:\s?form-data;\s?name="([^"]+)"
+(.*)$/i) {
      $name=$1;if ($2=~/filename="([^"]+)"/) { $filename=$1; }
      $section=2; # prepare for data
     }
    }
    if ($line=~/^$boundary(--)?$/) {
     $section=1;# found boundary
     if ((length($name)>0) && (length($filename)<1)) {
      chomp($mydata);chop($mydata); # munch munch
      $datasent.=";$name=$mydata";
      if (length($form{$name})>0) { $mydata=$form{$name}."\0".$mydata;
+ }
      $form{lc($name)}=$mydata;
     } elsif (length($name)>0) {
      $form_filenames{$name}=$filename;$form_contenttype{$name}=$conte
+nttype;
      $tempfile=$tempdir.(time())."_".int(rand(300000));
      $tempfile.=".tmp";
      open (DATA,">".$tempfile) || die("Unable to open temp directory 
+for storage\n");
      binmode(DATA);print DATA $mydata;close DATA;
      $form_data{$name}=$tempfile;
     }
     $name="";$mydata="";$filename="";$contenttype="";
    } 
    if ($section==4) {
     $mydata.=$line;
    }
   }
  }
 }
 $datasent.=";";
}
[download]