<form method="post" action="upload.mas" enctype="multipart/form-data">
  <input type="file" name="file_name" /><br />
  <input type="submit" value="Submit" />
</form>

<%init>
    use Apache2::Upload;
 
    # $r is an Apache2::RequestRec, not an Apache2::Request like some places say it is
    my $req = Apache2::Request->new($r);
 
    # file_name refers to the form name you had in your HTML
    my $upload = $req->upload('file_name');
 
    my $fh = $upload->fh;
    open OUTFILE, ">$where_ever_you_wanna_save_the)file";
 
    binmode $fh;
    binmode OUTFILE;
 
    print OUTFILE $line foreach my $line (<$fh>);
    close OUTFILE;
    close $fh;
</%init>