#!/usr/bin/perl

use CGI;
my $cgi = CGI->new();

if ($cgi->request_method() eq 'POST') {
    if (my ($my_param) = $cgi->param('my_param')) {
        print($cgi->header('text/plain'));
        close(STDERR);
        open(STDERR, '>&', \*STDOUT);
        exec 'my_prog', $my_param;
    }
}

print($cgi->header('text/html'));
print(<<'__EOI__');
<title>my_prog</title>
<form method="POST">
<h1>my_prog</h1>
<p>my_param: <input type="text" name="my_param">
</form>
__EOI__
}