Passing parameters to Perl Script

I have written a program in perl that, when given a server path, will report the size of every folder 1 level below the given path. The use for this is in determining the size of user home drives on a network. What I am trying to do now is run that script through a cgi/web interface. What I envision is that a user will come to a website where they will enter the path to the directory they want to search into a text box ( \\theserver\share ). What I can't figure out is how to pass this to my perl script as an input parameter. I should note that I only need it to accept 1 input when it's executed.

This leads to somewhat of another question. This script could, in reality, take a great deal of time to finish (30+ min.) depending on the size of the directories. Is there a way to keep the script running on the server, even after the user has closed their browser? I am planning on adding functionality to where the script will email the results to the user.

Here is what I have now. Keep in mind that I have not modified it at all to be run on a web server. As it is shown below, it accepts input (server names) from a file and outputs the results to a file.

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use File::Find;
use strict;

my ($dir, @parts, $error);

open(IN, "< input.csv") or die("Couldn't open input.csv\n");
open(OUT, "> output.csv") or die("Couldn't open output.csv\n");

#Separates input by line
chomp ( @parts = <IN> );

#Prints headings for output
print OUT "Path,MB,Errors\n";

 
       use File::Find;
       use File::Spec;
       use strict;
       
       my $cur = File::Spec->curdir;
       my $up  = File::Spec->updir;
       my $dirtot;
       
       #Displays total for subdirectories
       foreach my $start (@parts) {
          my @dirs = &find_subdirs($start);
       
          foreach my $dir (@dirs) {
             print "Walking $dir\n";
               my $total = 0;
             find sub { $total += -s }, $dir;
             $dirtot = $dirtot + $total;                                                  #Used for determining total directory size
                   $total = ($total / 1024) / 1024;            #Converts to MB
                   $total = sprintf("%0.2f", $total);            #Formats output to 2 decimals
                   print OUT "$dir,$total,$!\n";
          }
          print STDERR "$start: No subdirectories\n" unless @dirs;
       }
       
       sub find_subdirs {
          my $start = shift;
       
          unless(opendir(D, $start)) {
             warn "$start: $!\n";
             next;
          }
       
          my @dirs =
             map {
                 -d "$start/$_" &&
                !-l "$start/$_" &&
                $_ ne $cur && $_ ne $up
                   ? "$start/$_" : ()
             }
             readdir(D);
       
          closedir(D);
       
          @dirs;
       }
 close(OUT);
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I'm really not sure where to go from here. I haven't been working with Perl for a real long time, and I am brand new to CGI. I appreciate anyone's comments.