如何使用CGI :: Application获取上传文件的内容类型？

#!/usr/bin/perl

use strict;
use warnings;
use CGI::Application;

# 创建一个新的CGI应用程序
my $app = CGI::Application->new;

# 定义一个处理上传文件的子例程
sub handle_upload {
    my $cgi = shift;
    my $upload = $cgi->param('upload');
    my $content_type = $upload->type;
    print "Content-Type: text/plain\n\n";
    print "上传文件的内容类型为：$content_type\n";
}

# 运行应用程序
$app->run(\&handle_upload);